WO2008094840A2

WO2008094840A2 - Hydrogen generation processes using silicon compounds

Info

Publication number: WO2008094840A2
Application number: PCT/US2008/052127
Authority: WO
Inventors: Raymond E. Paggi; Michael D. Redemer; Benjamin Root
Original assignee: Hydrogen Solutions International
Priority date: 2007-02-01
Filing date: 2008-01-25
Publication date: 2008-08-07
Also published as: WO2008094840A3

Abstract

There are disclosed are compositions that include various silicon-based compounds such as polysilanes, layered polysilanes, organosilanes or siloxenes, that are used to generate hydrogen. Methods and devices for generating hydrogen are also disclosed, including those directed to the processes of generating hydrogen for fuel cells or as a supplementary fuel for internal combustion engines.

Description

HYDROGEN GENERATION PROCESSES USING SILICON COMPOUNDS

TECHNICAL FIELD

[0001] The present invention generally relates to improved compositions and methods for generation of hydrogen using silicon-based compounds. More particularly, the invention is concerned with methods for generating hydrogen using organosilanes, polysilanes, and suicides and catalyst(s) under particular and specific reaction conditions.

BACKGROUND INFORMATION

[0002] The ability to store hydrogen efficiently, economically and safely is one of the challenges to be overcome to make hydrogen an economic source of energy. There have been described the limitations in the current commercialization of fuel cells, internal combustion engines fueled with hydrogen, and engine exhaust after-treatment systems utilizing hydrogen. Technology and processes that utilize certain silicon based compounds to generate hydrogen safely and efficiently in the amounts needed by the device on an "as needed" basis have been also described previously.

[0003] Previously, a process was described where the hydrolysis of organosilicon compounds (e.g., organosilanes) was used to generate hydrogen safely and on as needed basis, eliminating the need for storage of large amounts of hydrogen in pressure vessels. It was theorized that the dilute strong base provided hydroxyl ions throughout the aqueous mixture while the amine floated to the surface of the water as did the organosilanes.

[0004] Further research has led to the discovery of processes and hardware that enable the reaction to proceed more rapidly, yield a larger amount of hydrogen and enhanced separation of the precipitate from the reaction zone preventing premature termination of the process. Specifically, the generation of a vortex in the mixing process has demonstrated this improvement. The addition of a nucleation site such as that provided by absorbed glass mat provides similar improvement. [0005] There remains a need for further improvements in efficiency, performance, and cost effectiveness of such clean energy sources, for a variety of applications, such as portable and stationary fuels cells or emissions control systems for motor vehicles. There remains a need for improvements which exhibit enhanced efficiency, performance, and that are cost effective. We provide processes and devices that can be used to meet such needs.

SUMMARY

[0006] We provide compositions and process(s) for use in generation of hydrogen, as it is needed, in a safe and controlled manner, for use as a fuel in a fuel cell, in an engine as a NOx reducing agent or as a supplementary fuel or for any other hydrogen consuming device, using silicon-containing compounds as a starting material, resulting in improved efficiency and allowing to avoid generating airborne pollutants.

[0007] We also describe new devices for commercial applications and new silicon-containing compounds that can be used to generate hydrogen as needed. . We have further determined that a mixture of a dilute strong base such as KOH or NaOH along with an organic amine enables the reaction to initiate and be self-sustaining without any agitation.

[0008] In some embodiments, we provide silicon-containing compounds that have been shown to be an effective fuel for generating hydrogen as needed. For example, we provide several new silicon based compounds that can be used for this purpose, including but not limited to, powdered siloxene, layered polysilane Si₆H₆, and various silanes and oligosilanes, including a silane oligomer with at least three repeating groups. We further provide mixtures of dilute strong bases and an organic amine that improve the rate of reaction generating hydrogen. We further provide for the addition or inclusion of hardware, material or processes that enhance the nucleation of the reaction to improve the rate of the reaction generating hydrogen, the overall yield of the reaction and also enhance the separation of the precipitate formed. Devices that incorporate these materials and processes are also disclosed. [0009] In further embodiments, we provide for viable catalysts for the continuing replenishment for hydroxyl ions into the liquid phase of the reaction. In one non-limiting embodiment such a catalyst is calcium oxide.

[0010] The invention also provides for the use of combinations of catalysts that include alkali, such as potassium hydroxide (KOH) or sodium hydroxide (NaOH), and an organic amine catalyst, to produce hydrogen (H₂) on an as needed basis by altering the reaction conditions. An exemplary combination is two or more of octylamine, aniline, ethanolamine (EtOHNH₂), NaOH, and KOH. Functionalized octylamine catalysts are also within the scope of the invention.

[0011] We also provide for various reaction conditions under which hydrogen may be generated, including self-initiating reaction that is self-sustaining without agitation; the use of UV light; enhancing the rate of the reaction by separating hydrogen from the starting materials by enhanced nucleation (e.g., by use of an absorbed glass mat and the generation of a vortex during the mixing process); and combinations of specific starting materials and catalysts that result in enhanced gravimetric efficiency and/or can increase the rate of the hydrogen generation reaction.

[0012] The processes of silane hydrolysis described in the present application allow to obtain hydrogen yields that may be two to three times higher than those obtainable using other fuel cell technologies, due to the fact the co-reactant is water, which can be collected in situ, precluding the need to carry the extra weight. Also, unlike methanol or hydrocarbon fueled fuel cell technologies, the processes of the present invention allow to avoid formation of carbon dioxide which is a harmful green house gas. The precipitate formed in the processes of the present invention is non-hazardous and non-valuable and need not be recovered, as opposed to sodium borohydride, lithium hydride or other by-products which are formed when other technologies are used, thus providing significant advantage to the consumer.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 illustrates schematically the overall hydrogen generation process. [0014] Figure 2 illustrates schematically a cartridge-type hydrogen generator for portable power applications.

[0015] Figure 3 illustrates schematically a hydrogen generator for use with light duty automotives.

[0016] Figure 4 illustrates schematically a hydrogen generator for heavy duty applications.

[0017] Figure 5 illustrates schematically a system using powder siloxene or layered polysilane prepared from calcium suicide.

DETAILED DESCRIPTION

[0018] The following definitions are used below, unless otherwise described:

[0019] Throughout the description and claims of this specification the word "comprise" and other forms of the word, such as "comprising" and "comprises," means including but not limited to, and is not intended to exclude, for example, other additives, components, integers, or steps.

[0020] As used in the description and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a composition" includes mixtures of two or more such compositions, reference to "an organosilane" includes mixtures of two or more such organosilanes, reference to "the silane" includes mixtures of two or more such silanes, and the like.

[0021] "Optional" or "optionally" means that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where the event or circumstance occurs and instances where it does not. For example, statements about a device that optionally contains a check valve refers to devices that have a check valve and devices that do not have a check valve.

[0022] Ranges can be expressed herein as from "about" one particular value, and/or to "about" another particular value. When such a range is expressed, another aspect includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. It is also understood that there are a number of values disclosed herein, and that each value is also herein disclosed as "about" that particular value in addition to the value itself. For example, if the value "10" is disclosed, then "about 10" is also disclosed. It is also understood that when a value is disclosed that "less than or equal to" the value, "greater than or equal to the value" and possible ranges between values are also disclosed, as appropriately understood by the skilled artisan. For example, if the value "10" is disclosed, then "less than or equal to 10" as well as "greater than or equal to 10" is also disclosed. It is also understood that throughout the application data are provided in a number of different formats and that this data represent endpoints and starting points and ranges for any combination of the data points. For example, if a particular data point "10" and a particular data point "15" are disclosed, it is understood that greater than, greater than or equal to, less than, less than or equal to, and equal to 10 and 15 are considered disclosed as well as between 10 and 15. It is also understood that each unit between two particular units are also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.

[0023] References in the specification and concluding claims to parts by weight or mass of a particular element or component in a composition denotes the weight or mass relationship between the element or component and any other elements or components in the composition or article for which a part by weight is expressed. Thus, in a compound containing 2 parts by weight of component X and 5 parts by weight component Y, X and Y are present at a weight ratio of 2:5, and are present in such ratio regardless of whether additional components are contained in the compound.

[0024] A weight or mass percent (wt. % or mass %) of a component, unless specifically stated to the contrary, is based on the total weight of the formulation or composition in which the component is included. As used herein the term "gravimetric efficiency" means the yield of hydrogen per unit weight of starting material. A high gravimetric efficiency is achieved by optimization of starting materials, catalysts, and processes.

[0025] As used herein the term "as needed basis" used interchangeably with the term "on demand" refers to the ability to control the reaction conditions wherein the amount of hydrogen produced is controlled.

[0026] As used herein the term "in a controlled manner" means the amount of hydrogen produced can be varied in a predictable manner by alteration of the reaction conditions.

[0027] As used herein the term "reaction conditions" includes, but is not limited to, temperature, feed rate, stoichiometry, the order of mixing of reagents, and pressure.

[0028] As used herein, the term "substituted" is contemplated to include all permissible substituents of organic or inorganic compounds. In one example, the permissible substituents can include acyclic and cyclic, branched and unbranched, carbocyclic and heterocyclic, and aromatic and nonaromatic substituents of compounds. Illustrative substituents include, for example, those described below. The permissible substituents can be one or more and the same or different for appropriate compounds. For the purposes of this disclosure, the heteroatoms, such as nitrogen, can have hydrogen substituents and/or any permissible substituents of organic or inorganic compounds described herein which satisfy the valences of the heteroatoms. This disclosure is not intended to be limited in any manner by the permissible substituents of compounds.

[0029] "A¹," "A²," "A³," and "A⁴" are used herein as generic symbols to represent various specific substituents. These symbols can be any substituent, not limited to those disclosed herein, and when they are defined to be certain substituents in one instance, they can, in another instance, be defined as some other substituents.

[0030] The term "alkane" as used herein is a branched or unbranched saturated hydrocarbon group having the general formula of C_nH_2n+2 and can have from 1 to 40 carbon atoms, such as methyl, ethyl, w-propyl, isopropyl, «-butyl, ώø-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, eicosyl, tetracosyl, and the like. The alkane can also be cyclic, substituted, or unsubstituted, which are included within the meaning of the term "alkane." A cyclic alkane can specifically be referred to as a cycloalkane, but these structures are included within the meaning of the term "alkane." A radical of an alkane can be specifically referred to as an "alkyl," but throughout the disclosure alkyls are also intended to be included within the meaning of alkanes.

[0031] A "cycloalkyl" is a type of alkyl group and is included within the meaning of the word "alkyl." A cycloalkyl group is a non-aromatic carbon-based ring composed of at least three carbon atoms. Examples of cycloalkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc. The term "heterocycloalkyl" is a type of cycloalkyl group, and is included within the meaning of "alkyl" and "cycloalkyl," where at least one of the carbon atoms of the ring is substituted with a heteroatom such as, but not limited to, nitrogen, oxygen, sulfur, or phosphorus. The cycloalkyl group and heterocycloalkyl group can be substituted or unsubstituted. The cycloalkyl group and heterocycloalkyl group can be substituted with one or more groups including, but not limited to, alkyl, alkoxy, alkenyl, alkynyl, aryl, heteroaryl, aldehyde, amino, carboxylic acid, ester, ether, halide, hydroxy, ketone, nitro, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, or thiol as described herein.

[0032] The term "alkoxy" as used herein is an alkyl group bound through a single, terminal ether linkage; that is, an "alkoxy" group can be defined as — OA¹ where A¹ is alkyl as defined above.

[0033] The term "alkene" as used herein is a hydrocarbon group of from 2 to 40 carbon atoms with a structural formula containing at least one carbon-carbon double bond. Asymmetric structures such as (A¹A^C=C(A³A⁴) are intended to include both the E and Z isomers. This may be presumed in structural formulas herein, wherein an asymmetric alkene is present, or it may be explicitly indicated by the bond symbol C=C. The alkene can also be cyclic, substituted, or unsubstituted, which are included within the meaning of the term "alkene." A cyclic alkene can specifically be referred to as a cycloalkene, but these structures are included within the meaning of the term "alkene." A radical of an alkene can be specifically referred to as an "alkenyl," but throughout the disclosure alkenyls are also intended to be included within the meaning of alkenes.

[0034] A "cycloalkenyl" is a type of alkenyl group and is included within the meaning of the word "alkenyl." A cycloalkenyl group is a non-aromatic carbon-based ring composed of at least three carbon atoms and containing at least one double bound, i.e., C=C. Examples of cycloalkenyl groups include, but are not limited to, cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclopentadienyl, cyclohexenyl, cyclohexadienyl, and the like. The term "heterocycloalkenyl" is a type of cycloalkenyl group, and is included within the meaning of the terms "alkenyl" and "cycloalkenyl," where at least one of the carbon atoms of the ring is substituted with a heteroatom such as, but not limited to, nitrogen, oxygen, sulfur, or phosphorus. The cycloalkenyl group and heterocycloalkenyl group can be substituted or unsubstituted. The cycloalkenyl group and heterocycloalkenyl group can be substituted with one or more groups including, but not limited to, alkyl, alkoxy, alkenyl, alkynyl, aryl, heteroaryl, aldehyde, amino, carboxylic acid, ester, ether, halide, hydroxy, ketone, nitro, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, or thiol as described herein.

[0035] The term "alkyne" as used herein is a hydrocarbon group of 2 to 40 carbon atoms with a structural formula containing at least one carbon-carbon triple bond. The alkyne can also be cyclic, substituted, or unsubstituted, which are included within the meaning of the term "alkyne." A radical of an alkyne can be specifically referred to as an "alkynyl," but throughout the disclosure alkynyls are also intended to be included within the meaning of alkynes.

[0036] The term "aryl" as used herein is a group that contains any carbon-based aromatic group including, but not limited to, benzene, naphthalene, phenyl, biphenyl, phenoxybenzene, and the like. The term "aryl" also includes "heteroaryl," which is defined as a group that contains an aromatic group that has at least one heteroatom incorporated within the ring of the aromatic group. Examples of heteroatoms include, but are not limited to, nitrogen, oxygen, sulfur, and phosphorus. Likewise, the term "non-heteroaryl," which is also included in the term "aryl," defines a group that contains an aromatic group that does not contain a heteroatom. An aryl can also be substituted or unsubstituted, which are included within the meaning of the term "aryl." The term "biaryl" is a specific type of aryl group and is included in the definition of "aryl." "Biaryl" refers to two aryl groups that are bound together via a fused ring structure, as in naphthalene, or are attached via one or more carbon-carbon bonds, as in biphenyl.

[0037] The term "silane" as used herein is represented by the formula H — SiA¹A²A³, where A¹, A², and A³ can be, independently, hydrogen, or a substituted or unsubstituted alkyl, alkoxy, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, or cycloalkenyl. Generally, the term "silane" means a silicon analogue of an alkane, alkoxyl, alkene, alkyne, or aryl where one, more than one, or all carbon atoms in those structures are replaced by a silicon atom and at least one of the silicon atoms is covalently bonded to a hydrogen atom.

[0038] In some examples, a silane can be analog of an unsubstituted alkane and have the general formula of Si_nH_2n+2. Such structures are typically named according to regular nomenclature where the word "silane" is preceded by a numerical prefix (di, tri, tetra, etc.) for the number of silicon atoms in the molecule. Thus, Si₂H₆ is disilane, Si₃H₈ is trisilane, and so forth. There is usually no prefix for one, as SiH₄ is referred to as simply "silane." Silanes can also be named like any other inorganic compound; for example, silane can be named silicon tetrahydride, disilane can be named disilicon hexahydride, and so forth. Silanes that are substituted with a hydroxy group are called silanols.

[0039] In other examples disclosed herein, a silane can be substituted with one or more organic groups such as an alkane, alkene, alkyne, or aryl. Such structures, which contain a silicon-carbon bond, are typically referred to as organosilanes. Examples of some well known organosilanes include teft-butyldimethylsilane, trimethylsilane, phenylsilane, and the like. Silanes with more than one silicon atom can also be referred to as polysilanes.

[0040] Throughout this disclosure and the appended claims, the term "silane" is intended to include organosilanes, polysilanes, branched silanes, cyclic silanes, substituted silanes (e.g., silanols), and unsubstituted silanes, though in some instances these structures can be referred to specifically herein. Further, a radical of such a silane can be specifically referred to as a "silyl," but throughout the disclosure silyls are also intended to be included within the meaning of silanes.

[0041] The term "halide" as used herein refers to the halogens fluorine, chlorine, bromine, and iodine.

[0042] The term "hydroxyl" as used herein is represented by the formula -OH.

[0043] The terms "amine" or "amino" as used herein are represented by the formula NA¹A²A³, where A¹, A², and A³ can be, independently, hydrogen, an alkyl, halogenated alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, or heterocycloalkenyl group described above.

[0044] Unless stated to the contrary, a formula with chemical bonds shown only as solid lines and not as wedges or dashed lines contemplates each possible isomer, e.g., each enantiomer and diastereomer, and a mixture of isomers, such as a racemic or scalemic mixture.

[0045] The term "a catalyst" is defined as substance that changes the speed or yield of a chemical reaction without being itself substantially consumed or otherwise chemically changed in the process, or appearing as part of the product. Catalysts typically act by lowering the activation energy of reactions, but they do not change the relative potential energy of the reactants and products. The term "nucleation" is defined as

[0046] The term "nucleation" is defined as the beginning of chemical or physical changes at discrete points in a system.

[0047] The present invention is directed to generation of hydrogen as needed from non-toxic, energy-dense liquids and solids for use in fuel cells, internal combustion engines, engine exhaust after-treatment systems for reducing oxides of nitrogen and any other device that consumes hydrogen. The invention provides an overall lower weight than other systems, requires no expensive precious metal catalysts, emits no carbon dioxide or other pollutants. The starting material for this chemistry is very plentiful silicon dioxide which could also be harvested from rice straw or rice husks.

[0048] In general, disclosed herein are compositions, methods, and devices that address issues related to the perceived hazardous character, low hydrogen density, and poor regeneration capability of silanes as fuel. For example, the compositions, methods, and devices disclosed herein can reduce or eliminate the need to provide separation or clean-up of the hydrogen from gaseous by-products. The disclosed compositions and processes also mitigate/eliminate the hazardous nature of the starting materials and the precipitate, eliminating special handling and recovery logistics. Also, the disclosed compositions, methods, and devices can provide pressure to eliminate or reduce the need for mechanical pumping and assist the fuel cell with its own pumping needs. Moreover, the disclosed compositions, methods, and devices do not result in the release of carbon dioxide (or any other gaseous pollutants) to the atmosphere. And, in most instances disclosed herein, a residual by-product is formed, but it is environmentally benign (i.e., a silicate).

[0049] More specifically, we provide a method for generating hydrogen comprising hydrolyzing a silicon-containing compound in the presence of an organic amine catalyst and/or a hydroxide, i.e., reacting such a silicon-containing compound with water and a hydroxide. The use of the amine lowers the pH of the system and enhances the overall safety of the unit. Hydrogen is a product of this reaction. The method of the invention may be practiced using a variety of starting silicon-containing compound(s), organic amine catalysts, and hydroxides under various specific conditions, as discussed below in more detail. By varying and altering the specific conditions of the reacting we provide for substantially and unexpectedly improved gravimetric and volumetric efficiency, and for other advantages, as discussed below.

[0050] According to embodiments of the present invention, not every organic amine catalyst is capable of providing equally good results with every silicon-containing compound to be hydrolyzed. Therefore, the organic amine catalyst has to be matched to the specific silicon- containing compound to minimize the concentration of catalyst needed, to improve the rate of reaction or to optimize the hydrogen yield. For example, propylamine works well with siloxene but poorly with 1 ,4 disilabutane.

[0051] According to embodiments of the present invention, the order in which the materials are mixed significantly impacts the yield. The catalyst and water, therefore, should be mixed prior to the contact with the silane material to gain the optimum performance. The water and catalyst mixture may then either be added to the silicon-based compound or the silicon-based compound may be added to the water/catalyst mixture. To improve yields that may be as high as to approach theoretical yields, a slight excess of stoichiometric water has to be maintained locally for the organosilanes and a significant excess of water is needed for siloxene.

Starting Silicon-Containing Materials

[0052] Silicon-containing compounds that can be employed as starting products to generate hydrogen as needed include silanes, poly- or oligosilanes organosilanes, and siloxenes derived from suicides. All of the silicon-containing products that can be used are capable of being hydrolyzed or alcoholized under various conditions to produce hydrogen gas. The reaction is typically carried out in a basic solution, and in a presence of a catalyst, as discussed below in greater detail. One example of the process of generating hydrogen may be illustrated by the net reaction scheme I (hydrolysis of phenylsilane):

(I)

[0053] Reaction I (which omits showing the intermediate products) proceeds via a nucleophilic attack of the hydroxyl anion on the silane bond Si-H. If reaction I employs an amine, e.g., octyl amine catalyst, the reaction may proceed via formation of an ammonium cation, e.g., CH₃(CH₂)₇NH₃ ⁺ and hydroxyl, which form as a result of interaction of water with octyl amine. The hydroxyl then attacks the Si-H bond of phenylsilane leading to the formation of S-OH fragment and to the release of a proton, followed by generation of hydrogen gas and regeneration of octyl amine.

[0054] The reaction may be carried out at temperatures ranging between about -I⁰C and about 43⁰C and can utilize various kinds of water, including seawater, brackish water, distilled water, tap water, and water contained in urine. It is worth mentioning that water may be supplied from the effluent of the fuel cell or from the engine exhaust which may, therefore, help to lower the weight and volume of the system in these applications. In addition, the water recovered from the engine exhaust contains acids that are neutralized by the catalyst, thereby preventing harm to the vehicle components and lowering the amount ofNO_x required to be converted by the catalyst.

[0055] It is desirable that the starting silicon-containing compounds have low vapor pressure, high boiling point and high energy density with respect to hydrogen evolution capability. In several embodiments of the invention, compositions comprising silanes can be used to generate hydrogen, which in turn can be supplied, for example, to a fuel cell or an internal combustion engine or catalyst. Silanes or organosilanes that may be used include silane oligomers with at least three repeating groups, such as pentasilane, cyclopentasilane, substituted cyclopentasilane, hexasilane, cyclohexasilane and substituted cyclohexasilane all of which do have low vapor pressure, high boiling point and high energy density with respect to hydrogen evolution capability. Other silanes or organolsilanes that may be used include short chain hydrocarbons with at least one terminal silane group(s), disilabutane, disilapropane, layered polysilane Si₆H₆ (i.e., a product of reaction between calcium suicide and hydrochloric acid under cold conditions), and aromatic silanes such as phenylsilane, disilylbenzene, trisilylbenzene, and hexasilylbenzene.

[0056] Very dry powdered siloxenes may be also used as starting silicon-containing products for generating hydrogen by hydrolysis in the presence of a hydroxide and an amino catalyst. Powdered siloxenes having the net structure Si₆H₆O₃ are synthetic products that may be obtained from suicides using methods and techniques known to those skilled in the art, for example, by an exemplary reaction II:

3 CaSi₂ + H₂O + 6 HCl → Si₆H₆O₃ + 3 CaCl₂ + 3 H₂ (II) [0057] However, layered polysilane Si₆H₆ which may be also generated from the low temperature reaction of calcium suicide with hydrochloric acid has a higher gravimetric efficiency than siloxene because there are no oxygen atoms in the molecule. The presence of oxygen atoms reduces the amount of available silicon sites to be oxidized and also adds to the weight of the overall fuel.

[0058] Other silicon-containing products that can be employed as starting products to generate hydrogen as needed include the pyrolized ash of rice husks or the pyrolized ash of rice straw. The pyrolized ash of rice husks or the pyrolized ash of rice straw have been identified as renewable and environmentally favorable source of hydrogen generating fuels.

[0059] For example, rice straw contains up to twelve percent silicon, has no current value and has a cost for disposal. The silicon in rice husk and rice straw exists as silicon dioxide intermingled closely with cellulosic chains. It is well known that bulk silicon does not react with water because of a layer of silicon dioxide that builds up on the surface. However, under proper conditions, silicon may react rapidly with water, similar to the behavior of lithium, magnesium, sodium, aluminum and other metals.

[0060] Therefore, rice husk and rice straw can be pyrolized in a steam atmosphere to form a reduced silicic acid, or can be combined with magnesium to form amorphous silicon. The theoretical gravimetric efficiency in grams of hydrogen that could be produced per hundred grams of rice husk ash ranges from 14 to 17% according to the schematic equations III and IV:

Si + 2H₂O → SiO₂ + 2H₂ (III)

2Si + 8H₂O → 2SiO(OH)₃ + 5H₂ (IV)

[0061] Other reactions may also occur in the presence of other elements in the rice husk ash which may raise or lower the hydrogen yield. Catalysts

[0062] As discussed above, the hydrogen-generating process of hydrolysis of silicon- containing compounds is conducted in the presence of a catalyst. Strong acids, strong bases, and transition or precious metals may be used as catalysts. Typical catalysts that may be used include hydroxides, such as potassium or sodium hydroxide (KOH or NaOH), calcium oxide (CaO), or calcium hydroxide (Ca(OH)₂), and nitrogen-containing compounds, such as a soluble or insoluble amines.

[0063] For example, solid CaO can be an effective catalyst for the reaction of the silicon- based compounds with water to generate hydrogen. The limited solubility of Ca(OH)₂ in water provides the advantage of maintaining a continuous supply of hydroxyl ions as they are consumed in the reaction. In addition, CaO generates two hydroxyl ions per mole as opposed to NaOH and KOH which generate one hydroxyl ion per mole. The density and the effectiveness of this solid catalyst significantly reduces the volume and weight of the hydrogen generating system. The pH of the calcium hydroxide solution generated by the calcium oxide is also significantly less alkaline than a strong base catalyst improving the safe handling and disposal of commercial products using this technology.

[0064] Other suitable catalysts include, but are not limited to, 10% Pd-C, Pd-Cu, Raney nickel, 5% Ru-C, H₂PtCl₆, PdCl₂, PdOAc₂, CuOAc₂, superacid membranes, phosphonic acid containing membranes, sulfonic acid containing membranes, and polymers, along with alkaline membrane and polymers.

[0065] In the embodiments employing a nitrogen-containing catalyst, such as amines, examples of suitable amines include, but are not limited to, substituted or unsubstituted mono-, di-, and tri-alkyl amines, hydroxyalkylamines, substituted or unsubstituted mono-, di-, and tri- alkenylamines, and jeffamines, including combinations thereof. Some specific examples include, but are not limited to, triethylamine (TEA), tributylamine, ethylbutylamine, hexylenediamine, N,N-dimethylethanolamine (DMEDA), dimethylaminoethanol (DMEA), triethylenediamine (TEDA), ethylenediamine tetraacetic acid (EDTA), NJN- dimethylcyclohexylamine, N,N'-dimethylaniline, N,N,N',N'-tetramethylethylenedianiine (TMEDA), N,N,N',N",N"-pentamethyldiethylenetriamine (PMDETA), pyridine, dimethylaminopyridine, benzyldimethylamine, tris-(dimethylaminomethyl) phenol, alkyl- substituted imidazoles (e.g., 1,2- dimethylimidazole), phenyl-substituted imidazoles, or bis(2- dimethylaminoethyl) ether (BDMEE). In one particular example, the catalyst is an alkyl amine, such as methylamine, ethylamine, propylamine, isopropylamine, butylamine, tert-butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamin, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine, nonadecylamine, icosylamine, henicosylamine, doicosylamine, triicosylamine, tetraicosylamine, and the like. Some exemplary amine catalysts that may be used include propylamine and octylamine.

[0066] According to some embodiments of the invention, specific combinations of particular starting silicon-containing compounds paired with particular catalysts may lead to enhanced gravimetric efficiency and/or can increase the rate of the hydrogen generation reaction. Examples of such particularly beneficial specific combinations include propylamine paired with siloxene and 1,4-disilabutane paired with octylamine. The efficiency of such special pairs may be illustrated by the fact that closely related to 1,4-disilabutane is 1,3-disilabutane which in combination with octylamine provided only 6.8 % efficiency. Yet, 1,4-disilabutane/octylamine combination gave 13.3% efficiency. At the same time, short chain diamines in combination with 1,4-disilabutane were unable to start a reaction. Aniline, on the other hand, which is a weak base compared to the alkylamines, provided good results with 1,4-disilabutane.

Materials and Compositions.

[0067] Certain materials, compounds, compositions, and components disclosed herein can be obtained commercially or readily synthesized using techniques generally known to those of skill in the art. For example, the starting materials and reagents used in preparing the disclosed compounds and compositions are either available from commercial suppliers such as Aldrich Chemical Co., (Milwaukee, Wis.), Acros Organics (Morris Plains, Ν.J.), Fisher Scientific (Pittsburgh, Pa.), or Sigma (St. Louis, Mo.) or are prepared by methods known to those skilled in the art following procedures set forth in references such as Fieser and Fieser's Reagents for Organic Synthesis, Volumes 1-17 (John Wiley and Sons, 1991); Rodd's Chemistry of Carbon Compounds, Volumes 1-5 and Supplemental (Elsevier Science Publishers, 1989); Organic Reactions, Volumes 1-40 (John Wiley and Sons, 1991); March's Advanced Organic Chemistry, (John Wiley and Sons, 4th Edition); and Larock's Comprehensive Organic Transformations (VCH Publishers Inc., 1989).

[0068] Also, disclosed herein are materials, compounds, compositions, and components that can be used for, in conjunction with, in preparation for, or are the products of, the disclosed methods and compositions. It is understood that when combinations, subsets, interactions, groups, etc., of these materials are disclosed, that even if a specific reference of each various individual and collective combinations and permutation of these compounds may not be explicitly disclosed, each is specifically contemplated and described herein.

[0069] For example, if a composition is disclosed and a number of modifications that can be made to a number of components of the composition are discussed, each and every combination and permutation that are possible are specifically contemplated unless specifically indicated to the contrary. For example, each of the combinations of A-E, A-F, B-D, B-E, B-F, C-D, C-E, and C-F are specifically contemplated and should be considered disclosed just from the disclosure of A, B, and C; D, E, and F; and the example combination A-D. Likewise, any subset or combination of these is also specifically contemplated and disclosed. Thus, for example, the sub-group of A-E, B-F, and C-E are specifically contemplated and should be considered disclosed from the disclosure of A, B, and C; D, E, and F; and the example combination A-D. This concept applied to all aspects of this disclosure including, but not limited to, steps in methods of making and using the disclosed compositions. Thus, if there are a variety of additional steps that can be performed, it is understood that each of these additional steps can be performed with any specific aspect or combination of aspects of the disclosed methods, and that each such combination is specifically contemplated and should be considered disclosed. Reaction Conditions

[0070] The conditions of the process of generating hydrogen may be selected to optimize of the yield of hydrogen, mitigate potential safety risks and obtain other benefits. According to embodiments of the invention, the optimal steps of the process include:

(a) the segregated water-free, air-free and UV-light free storage of the polysilane, siloxene or organosilane fuel;

(b) mixing water and catalyst first to form the water/catalyst mixture, followed by adding either the silicon-containing compound to the water/catalyst mixture, or by adding the water/catalyst mixture to the silicon-containing compound, at the desired concentrations and feed rates necessary to maintain the required pressure and supply for each application using a process, or in the presence of materials, that will enhance the nucleation of the reaction;

(c) selectively isolating and directing the hydrogen obtained in step (b) through a delivery port to prevent contamination of the fuel cell or automotive catalyst or combustion chamber with unreacted, partially reacted or products of the complete reaction; and

(d) collecting and/or isolating the reaction products to avoid tying up the catalyst, interference with, or premature termination of, the reaction or the delivery of the hydrogen.

[0071] In performing steps (a) through (d) described above, the following guidelines may be followed. Mixing a catalyst with water first allows to achieve a yield that is significantly higher than that obtainable in a process utilizing any other order of steps. Indeed, mixing a catalyst with water first may lead to efficiency of the process that is 20 to 50% higher compared with that of the process when the water is mixed with the silane first, followed by mixing with the catalyst.

[0072] The catalyst may be mixed with water to obtain the concentration of the catalyst in water that is between about 2 and about 5 mass %, for example, about mass 5%, in the water. Typically, the process is expected to be slower at a lower part of the range of concentrations. The feed rate of the silicon-containing compound may be selected to ensure acceptable supply pressure of the resulting hydrogen. The supply pressure of hydrogen that has to be maintained may be determined by those having ordinary skill in the art and for most fuel cells it may be in a range between about from 0.2 atmosphere (i.e., ~ 3 psi) and about 0.7 atmosphere (i.e., ~ 10 psi). The supply pressure needed for automotive after-treatment systems may be between about 0.14 atmosphere (i.e., ~ 2 psi) and about 0.35 atmosphere (i.e., ~ 5 psi).

[0073] In the above-described step (c), selective isolation of hydrogen may be needed since the gas obtained in some instances o f the process may not be 100% pure hydrogen, but include partially reacted silanes. To selectively isolate and direct the hydrogen obtained in step (b), those having ordinary skill in the art may put a size exclusion membrane or filter in the outlet since the silicon compounds will have much bigger size than hydrogen. A secondary benefit of that will be to reflux those partially reacted compounds back into the reaction, improving the yield.

[0074] In performing the final above-described step (d) of the process, one should keep in mind that the intermediate product of the organosilane reaction is a silanol which may be present but is not shown on the reaction scheme I above. Silanol is known to react with some alkyl amines thus inactivating them. Therefore, having ordinary skill in the art may choose only those alkyl amines that do not interact with silanol. If silanol is formed, it quickly polymerizes via condensation reaction at its tails. This causes the formation of a cake that floats on the surface of the water. This cake may interrupt or even completely stop the reaction of hydrolysis. Therefore, a step of removing the precipitate may be performed to avoid the premature termination of the reaction.

[0075] In view of the foregoing, a process exemplifying the above-described processes may include, but is not limited to, the following steps:

(a) introducing water from the effluent of the fuel cell, from the engine exhaust or from another source ( including salt water from the ocean, urine or any other contaminated water source), under positive or negative pressure, to a mixing site; (b) mixing of the water with at least one catalyst to form a water/catalyst mixture having the concentration of the catalyst(s) within the above-discussed range;

(c) further mixing the water/catalyst mixture with a silicon-containing compound, e.g., a polysilane, organosilane, or siloxene at a feed rate that would ensure the above-described hydrogen supply pressure, the feed rate being controlled by check valves and/or sensors, to satisfy but not exceed the needs of the fuel cell, engine or exhaust after-treatment system and to maintain a slightly excess of stoichiometric water-to-the silicon-containing compound ratio;

(d) optionally using an induced vortex or a material such as absorbed glass mat to increase nucleation sites;

(e) building a pressure at the mixing site this forcing hydrogen through an exit port and through a selective membrane that prevents the flow of reaction products through the same port; and

(e) collecting the reaction products either in the reactor, in the fuel storage unit or a separate container.

[0076] It has also been discovered that the use of a process or material that enhances nucleation will improve the rate of reaction and the overall yield of hydrogen. The processes above are optimized for the individual application. For instance, the optimum amount of hydrogen generated may be of secondary importance to the cost of the chemistry and unit, to the management, collection and discharge of the reaction by-product, to the volume or weight of the fuel system, or to other criteria. The invention is partially based on the observation that a mixture of catalysts (i.e. a catalyst cocktail) can increase the rate of a hydrogen generation reaction, which enhances the ability to control the reaction, resulting in a process with enhanced commercial value.

[0077] The process of obtaining hydrogen may be speeded up and the yield of hydrogen may be improved by optionally using UV radiation. In one embodiment, for example, hexasilane may be used as a starting silane. The theoretical yield for the reaction of hexasilane with water and a catalyst is 15 kg of hydrogen for every 100 kg of hexasilane. The hydrogen yield may be increased from 15% to 21% if the Si-Si bonds could be broken to form six silyl radicals. Such cleavage of the Si-Si bonds may be facilitated by using UV radiation. For example, the reaction blend including hexasilane may be irradiated by UV light emitted from a mercury vapor lamp or from a UV light emitting diode potentially releasing all the hydrogen and forming amorphous SiO₂ as a by-product. Those skilled in the art may use similar techniques employing UV radiation on other starting silicon-containing products, as appropriate.

[0078] The process of obtaining hydrogen may be further accelerated and the yield of hydrogen may be improved by optionally using an induced vortex. The vortex may be created, for example, by flutes in the supply line and reaction chamber. When vortex was used, the bubbles of hydrogen were coming almost exclusively from the very center of the vortex, and the yield of hydrogen was increased by about 20 %.

[0079] In some embodiments, the process of obtaining hydrogen may be further accelerated and the yield of hydrogen may be improved by optionally using a material capable of causing the increase in nucleation sites, e.g., a fiber glass material, such as an absorbed glass mat. The use of materials increasing nucleation may help to pull the precipitate out of the reaction zone and prevent the formation of a cake or lid on the reaction. Hydrogen bubbled quickly from many sites on the fiberglass material and improved the yield by about 20%.

Devices

[0080] Devices or cartridges that can be used to generate hydrogen according to the methods of the present invention can be designed to be specific to each application, whether it be portable or stationary, and whether weight or volume is more important. The devices or cartridges connect to a fuel cell, to the intake air of an engine, to a vehicle exhaust after-treatment system or to any other device that needs hydrogen as a fuel. As shown in Figure 1, generally devices feed the reactants and catalyst as needed to a reaction zone. The call for the reactants to the reaction chamber can be controlled simply by a check valve responding to a pressure increase in the reaction zone or can be controlled by electronic activation of valves and pumps. The devices blend the reactants in the desired concentrations, segregate the resulting hydrogen gas, and deliver the gas to the fuel cell, engine, engine exhaust after-treatment system or other hydrogen consuming device. The devices can also contain a means for segregating and collecting the silicate precipitate, refluxing clean water, and preventing backflow of reaction products into the reactant streams.

[0081] One example of a device that may be used is shown in Figure 2. The device comprises a mixing chamber for mixing a polysilane or organosilane, water and catalyst(s). The mixing chamber can comprise an inlet for the polysilane or organosilane with check valve to regulate the amount of fuel introduced into the reaction zone to minimize pressure build up, and a water inlet also with a check valve. The reaction chamber can also comprise a silicate collector such as absorbed glass mat, which can be used to contain and/or remove the silicate by-product of the reaction. When a polysilane is used the reaction zone may also contain a source of UV light to catalyze the reaction.

[0082] Another example of a device that may be used, i.e., a device for automobiles or light duty trucks, is shown in Figure 3. The device comprises a metal housing with separated storage for the organosilane, polysilane or silicide-based fuel, and a reaction chamber. Water is condensed from the engine exhaust and directed to the device where it is first mixed with the catalyst and then mixed with the fuel. The hydrogen liberated is directed to the intake air system of the engine, or is directed to the exhaust gas after-treatment system or is directed to an onboard fuel cell. The precipitate is collected in the cartridge.

[0083] Yet another example of a device that may be used, i.e., a device that can produce large amounts of hydrogen, is shown in Figure 4. This device can use water condensed from engine exhaust or from any other source. The organosilane, polysilane or silicide-based fuel, water and catalyst are mixed in a reaction chamber and both the hydrogen and the precipitate is removed. This device has a hydrogen permeable membrane on the hydrogen outlet.

[0084] In still another example, a device to mix a powder silicide-based fuel is shown in Figure 5. The device incorporates a feed system for the powder. Water and catalyst is mixed with the fuel in the auger and hydrogen is collected using a hydrogen permeable membrane. The auger discharges the precipitate from the unit.

EXAMPLES

[0085] The following examples are provided to further illustrate the advantages and features of our processes and systems, but are not intended to limit the scope of this disclosure.

[0086] In reducing the invention to practice, samples of gas were collected and tested using a gas chromatograph to confirm the purity of hydrogen gas and a small fuel cell was operated for several days on the produced hydrogen gas.

Example 1

[0087] Table 1, below, shows some of the data collected employing nucleation methods to enhance the production of hydrogen. In the phenylsilane experiment, a small piece of absorbed glass mat and 2 ml of water was added to a 50 ml reaction vial. KOH was then added to make a 0.25 M solution. 0.050 ml of n-octylamine was added. A septum was then used to cover the neck of the flask. The side neck of the flask was then connected by tubing to a 250 ml graduated cylinder that was filled with water and then inverted and placed in a reservoir of water. 0.20 ml of phenylsilane was injected using a 1 ml syringe into the reaction vial. The gas generated during the reaction was collected in the top portion of the graduated cylinder displacing the water. The amount of gas collected in this reaction was twenty five percent higher than reactions described in U.S. Patent Application Serial No. 60/705,331, without the absorbed glass mat.

[0088] Also shown in Table 1 are the results of an experiment utilizing 1,4-disilabutane. In this test, 1000 ml of water was added to a 1 liter Erlenmeyer flaks along with sufficient NaOH to make a solution of 0.5 molarity. This mixture was stirred rapidly to generate a vortex to enhance nucleation of the reaction. 0.25 ml of 1, 4 disilabutane was injected into the flask. The amount of gas collected in this reaction was thirteen percent higher than reactions described in patent application 60/705,331 without an induced vortex. The calculated gravimetric efficiency which is the weight of the hydrogen generated divided by the weight of the phenylsilane is shown in the table.

Table 1. Nucleation Studies

Example 2

[0089] Table 2, below, shows some of the data collected utilizing mixtures of catalysts to enhance the rate of production of hydrogen. In these tests, a 4 ml of water was added to a 50 ml reaction vial. KOH was then added to make a 0.5 M solution. N-octylamine was added in the separate tests in the amount indicated in the table. A septum was then used to cover the neck of the flask. The side neck of the flask was then connected by tubing to a 250 ml graduated cylinder that was filled with water and then inverted and placed in a reservoir of water. ImI of phenylsilane was injected using a 1 ml syringe into the reaction vial. The gas generated during the reaction was collected in the top portion of the graduated cylinder displacing the water. The amount of gas collected in fifteen minutes in these reactions improves significantly with the addition of increasing amounts of n-octylamine to the KOH solution.

Table 2. Use Of Mixtures Of Catalysts (Hydrolysis of Phenylsilane)

Example 3 [0090] Table 3, below, shows some of the data collected to utilizing « -propylamine as a catalyst to enhance the rate of production of hydrogen and to lower the alkalinity of the starting material and by-products. In these tests, approximately 0.25 g of siloxene was added to a 50 ml reaction vial. A septum was then used to cover the neck of the flask. The side neck of the flask was then connected by tubing to a 1000 ml graduated cylinder that was filled with water and then inverted and placed in a reservoir of water. 0.1 ml of propylamine in solution with between 2.0 and 2.5 ml of water was injected using a 3 ml syringe into the reaction vial. The gas generated during the reaction was collected in the top portion of the graduated cylinder displacing the water. The amount of gas collected in less than ten seconds in these reactions improves significantly when propylamine replaces KOH or NaOH in the solution. The largest quantity of hydrogen gas collected with 0.5 M KOH as the catalyst was 160 ml.

Table 3. Use of ^-Propylamine as a Catalyst for Hydrolysis of Siloxene

[0091] Although methods, compositions and devices of the present invention have been described with reference to the above-discussed embodiments and examples, it will be understood that modifications and variations are encompassed within the spirit and scope of the disclosure as defined in the appended claims.

Claims

CLAIMSWHAT IS CLAIMED IS:

1. A method for generating hydrogen, comprising:

(a) combining water and a catalyst to obtain a water-catalyst mixture; followed by

(b) combining the water-catalyst mixture with a silicon-containing compound to carry out a reaction that generates hydrogen thereby,

wherein:

(i) the silicon-containing compound is selected from the group consisting of hexasilane, pentasilane, cyclopentasilane, substituted cyclopentasilane, cyclohexasilane, substituted cyclohexasilane, phenylsilane having one or more silane groups, disilylbenzene, trisilylbenzene, hexasilylbenzene, a powdered siloxene, a layered polysilane, a silane oligomer with at least three repeating groups, a short chain hydrocarbon with at least one terminal silane groups, disilabutane, disilapropane, a metal suicide, the pyrolized ash of rice husks, the pyrolized ash of rice straw, and a combination thereof;

(ii) the catalyst comprises a mixture consisting of a hydroxide and an organic amine,

wherein the hydroxide is selected from the group consisting of potassium hydroxide, sodium hydroxide, calcium oxide, calcium hydroxide, and combinations thereof,

with the further proviso that hydrogen is produced in situ on an as needed basis.

2. The method of claim 1 , wherein the water-catalyst and the silicon-containing compound are combined at a rate to generate a predetermined pressure and supply of hydrogen, with the further proviso that the pressure build up is monitored in a mixing chamber and controlled by the opening and closing of check valves.

3. The method of claim 1 , further comprising catalyzing the reaction by short wavelength UV light.

4. The method of claim 1, further comprising enhancing the rate of the reaction and separating the hydrogen from the starting by enhanced nucleation.

5. The method of claim 4, wherein the enhanced nucleation is accomplished by use of an absorbed glass mat and the generation of a vortex during the mixing process.

6. The method of Claim 1, wherein the organic amine catalyst comprises octylamine.

7. The method of claim 6, wherein the organic amine catalyst comprises the combination of at least two of propylamine, octylamine, aniline, and ethanolamine.

8. The method of claim 7, wherein the combination comprises octylamine.

9. The method of claim 1 , wherein the water is selected from the group consisting of brackish water, distilled water, seawater, tap water, and water contained in urine.

10. The method of claim 1, wherein the water is supplied from the fuel cell effluent or the engine exhaust.

11. The method of claim 1 , further comprising supplying the produced hydrogen to a device selected from the group consisting of a fuel cell, an engine exhaust after-treatment system, and an engine combustion chamber.

12. The method of claim 1, wherein the silicon-containing compound is selected from the group consisting of powdered siloxene, layered polysilane and a silane oligomer with at least three repeating groups.

13. The method of claim 12, wherein the silicon-containing compound is powdered siloxene.

14. The method of claim 12, wherein the silicon-containing compound is a layered polysilane.

15. The method of claim 12, wherein the silicon-containing compound is a silane oligomer with at least three repeating groups.

16. The method of claim 1, wherein the gravimetric efficiency is enhanced to a degree selected from the group consisting of at least 4%, at least 5%, at least 6%, at least 7%, at least 8%, at least 9%, at least 10%, at least 11%, at least 12%, at least 13%, and at least 14%.

17. The method of claim 1, wherein the catalyst comprises a compound selected from the group consisting of a substituted or unsubstituted mono-, di-, and tri-alkyl amine, hydroxyalkylamine, substituted or unsubstituted mono-, di-, tri-alkenylamine.

18. The method of claim 17, wherein the catalyst is an alkyl amine, selected from the group consisting of methylamine, ethylamine, propylamine, isopropylamine, butylamine, tert- butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine, nonadecylamine, icosylamine, henicosylamine, doicosylamine, triicosylamine, tetraicosylamine, and combinations thereof.

19. The method of claim 1, wherein the catalyst comprises a compound selected from the group consisting of PdAc, CuAc, CuSO₄, octylamine, aniline, ethanolamine, NaOH, KOH, β- picoline, propylamine, hexyl diamine, pentadecylamine, tributyl amine, tert-butyl amine, ethylbutyl amine, decylamine and combinations thereof.

20. The method of claim 19, wherein the catalyst comprises propylamine.

21. The method of claim 19, wherein the catalyst comprises the combination of at least two of octylamine, propylamine, aniline, ethanolamine, NaOH, CaO, Ca(OH)₂ and KOH.

22. The method of claim 19, wherein the combination comprises propylamine and KOH.

23. The method of claim 1, wherein the silicon-containing compound is selected from the group consisting of the pyrolized ash of rice husks, the pyrolized ash of rice straw, and a combination thereof.

24. A device for generating hydrogen on an as needed basis in a controlled manner, comprising:

(a) a mixing chamber for mixing:

(i) a silicon-containing compound selected from the group consisting of an organosilane, a suicide, a powdered siloxene, and a layered polysilane;

(ii) water; and

(iii) optionally, a catalyst;

(b) a reaction chamber comprising a hydrogen outlet; and

(c) a hydrogen outlet comprising a hydrogen permeable membrane.

25. The device of claim 24, further comprising at least one check valve and at least one sensor for controlling the rate of generation the hydrogen.

26. The device of claim 24, wherein the reaction chamber further comprises a silicate collector.

27. The device of claim 24, wherein the mixing chamber comprises a mixing tee.

28. The device of claim 24, wherein the mixing chamber comprises a UV-light source.

29. The device of claim 24, wherein the hydrogen outlet comprises a hydrogen permeable membrane.

30. A hydrogen fuel cell, comprising a device of any one of claims 24 or 25.

31. An internal combustion engine comprising a hydrogen source, wherein the hydrogen source comprises a device of any one of claims 24 or 25.

32. An exhaust gas treatment system for an internal combustion engine comprising a hydrogen source, wherein the hydrogen source comprises a device of any one of claims 24 or 25.

33. A composition for generating hydrogen on an as needed basis in a controlled manner, comprising:

(a) water;

(b) siloxene; and

(c) a propylamine catalyst,

wherein the propylamine catalyst is present in the amount of between about 0.1 and about 5 mass % of the siloxene, and the mass ratio of water to siloxene is between about 1:1 and about 10:1.

34. The composition of claim 33, wherein hydrogen is generated at the gravimetric efficiency that is enhanced to a degree selected from the group consisting of at least 4%, at least 5%, at least 6%, at least 7%, at least 8%, at least 9%, at least 10%, at least 11%, at least 12%, at least 13%, and at least 14%.

35. A composition for generating hydrogen on an as needed basis in a controlled manner, comprising:

(a) water;

(b) a silicon-containing compound selected from the group consisting of phenylsilane and 1, 4-disilabutane; and

(c) an octylamine catalyst, wherein the octylamine catalyst is present in the amount of between about 0.5 and about 10 mass % of the silicon-containing compound, and the mass ratio of water to the silicon-containing compound is between about 4:1 and about 8:1.

36. The composition of claim 35, wherein hydrogen is generated at the gravimetric efficiency that is enhanced to a degree selected from the group consisting of at least 4%, at least 5%, at least 6%, at least 7%, at least 8%, at least 9%, at least 10%, at least 11%, at least 12%, at least 13%, and at least 14%.

37. The method of claim 1, wherein the silicon-containing compound is the powdered siloxene, and the organic amine is propylamine.

38. The method of claim 1 , wherein the silicon-containing compound is selected from the group consisting of phenylsilane and 1, 4-disilabutane, and the organic amine is octylamine.