TWI778890B

TWI778890B - Catalyst and method for selectively chemically reducing co to form co

Info

Publication number: TWI778890B
Application number: TW110146665A
Authority: TW
Inventors: 吳國卿; 許希彥; 陳朝煌; 杜遠朋
Original assignee: 財團法人工業技術研究院
Priority date: 2021-12-14
Filing date: 2021-12-14
Publication date: 2022-09-21
Also published as: TW202322902A

Abstract

A method for selectively chemically reducing CO ₂to form CO includes providing a catalyst, and contacting H ₂and CO with the catalyst to chemically reduce CO ₂to form CO. The catalyst includes a metal oxide having a chemical formula of Fe _xCo _yMn ₍ _1-x-y)O _z, in which 0.7≤x≤0.95, 0.01≤y≤0.25, and z is an oxidation coordination number.

Description

選擇性還原CO2成CO的觸媒與方法Catalyst and method for selective reduction of CO2 to CO

本揭露關於選擇性還原CO ₂成CO的製程，更特別關於其所用的觸媒。 The present disclosure relates to a process for the selective reduction of CO ₂ to CO, and more particularly to a catalyst used therefor.

全球暖化使得CO ₂的應用越來越受到重視，將CO ₂轉化為甲烷與甲醇受到熱力學限制，其轉化率都不高，若能先將CO ₂轉化成CO，再轉化成其他碳氫化合物(FT反應)，其轉化率就可大幅提高。CO是化學工業的關鍵建構原料，全球產值約58.7億美元 (主要生產醋酸、OXO醇等) 。台灣的醋酸產量達75萬噸/年，初步統計台灣CO年需求超過數拾萬噸/年。 Global warming makes the application of CO ₂ more and more attention. The conversion of CO ₂ into methane and methanol is limited by thermodynamics, and its conversion rate is not high. If CO ₂ can be converted into CO first, and then into other hydrocarbons (FT reaction), the conversion rate can be greatly improved. CO is a key building material for the chemical industry, with a global output value of about US$5.87 billion (mainly producing acetic acid, OXO alcohol, etc.). Taiwan's acetic acid output reaches 750,000 tons per year, and preliminary statistics show that Taiwan's annual CO demand exceeds several hundred thousand tons per year.

將CO ₂還原成CO，一般都是以逆水氣轉移反應進行，其反應式為H ₂+ CO ₂→ CO + H ₂O，其反應熱為41.2 kJ/mole。因此高溫下有利於逆水氣反應，而在低溫下有利於水氣轉移反應。水氣轉移反應的反應式為CO + H ₂O → H ₂+ CO ₂，其反應熱為-41.2 kJ/mole。然而氫氣與CO ₂亦產生甲烷化反應，其反應式為4H ₂+ CO ₂→ CH ₄+ 2H ₂O，其反應熱為-165 kJ/mole。由熱力學可知，低溫有利於水氣轉移反應與甲烷化反應。然而將CO ₂還原成CO的已知方法溫度偏高(比如高達600℃)，且CO的選擇率偏低(比如產物含有高濃度的甲烷而需分離，因此增加製造CO的成本)。 The reduction of CO ₂ to CO is generally carried out by reverse water gas shift reaction, the reaction formula is H ₂ + CO ₂ → CO + H ₂ O, and the reaction heat is 41.2 kJ/mole. Therefore, the reverse water-vapor reaction is favorable at high temperature, and the water-vapor transfer reaction is favorable at low temperature. The reaction formula of the water-gas shift reaction is CO + H ₂ O → H ₂ + CO ₂ , and the reaction heat is -41.2 kJ/mole. However, hydrogen and CO ₂ also produce methanation reaction, the reaction formula is 4H ₂ + CO ₂ → CH ₄ + 2H ₂ O, and the reaction heat is -165 kJ/mole. From the thermodynamics, low temperature is beneficial to the water vapor transfer reaction and the methanation reaction. However, known methods of reducing CO2 to _CO2 are relatively high temperature (eg up to 600°C) and CO2 selectivity is relatively low (eg the product contains high concentration of methane and needs to be separated, thus increasing the cost of CO production).

綜上所述，目前亟需新的觸媒以在低溫下選擇性還原CO ₂成CO，並降低CO產物中的CH ₄含量。 In conclusion, new catalysts are urgently needed to selectively reduce _CO to CO at low temperature and reduce the CH content in CO products _.

本揭露一實施例提供之選擇性還原CO ₂成CO的觸媒，包括：金屬氧化物，其化學式為Fe _xCo _yMn _(1-x-y)O _z，其中0.7≤x≤0.95，0.01≤y≤0.25，且z為氧化配位數。 An embodiment of the present disclosure provides a catalyst for selectively reducing CO ₂ to CO, comprising: a metal oxide, the chemical formula of which is F _x Co _y Mn _(1-xy) O _z , wherein 0.7≤x≤0.95, 0.01≤y ≤0.25, and z is the oxidation coordination number.

本揭露一實施例提供之選擇性還原CO ₂成CO的方法，包括：提供上述選擇性還原CO ₂成CO的觸媒；以及將H ₂與CO ₂與觸媒接觸，使CO ₂還原成CO。 An embodiment of the present disclosure provides a method for selectively reducing CO ₂ to CO, including: providing the above-mentioned catalyst for selectively reducing CO ₂ to CO; and contacting H ₂ with CO ₂ and the catalyst to reduce CO ₂ to CO .

本揭露一實施例提供之選擇性還原CO ₂成CO的觸媒，包括：金屬氧化物，其化學式為Fe _xCo _yMn _(1-x-y)O _z，其中0.7≤x≤0.95，0.01≤y≤0.25，且z為氧化配位數。若Fe的比例過高或過低，則CO ₂的轉換效率不足，或選擇性還原CO ₂成CO的效果不良(比如產物中的CH ₄含量過高)。若Co的比例過高或過低，則CO ₂的轉換效率不足，或選擇性還原CO ₂成CO的效果不良(比如產物中的CH ₄含量過高)。若Mn的比例過高或過低，則CO ₂的轉換效率不足，或選擇性還原CO ₂成CO的效果不良(比如產物中的CH ₄含量過高)。 An embodiment of the present disclosure provides a catalyst for selectively reducing CO ₂ to CO, comprising: a metal oxide, the chemical formula of which is F _x Co _y Mn _(1-xy) O _z , wherein 0.7≤x≤0.95, 0.01≤y ≤0.25, and z is the oxidation coordination number. If the proportion of Fe is too high or too low, the conversion efficiency of CO ₂ will be insufficient, or the effect of selectively reducing CO ₂ to CO will be poor (for example, the content of CH ₄ in the product is too high). If the proportion of Co is too high or too low, the conversion efficiency of CO ₂ will be insufficient, or the effect of selectively reducing CO ₂ to CO will be poor (for example, the content of CH ₄ in the product is too high). If the ratio of Mn is too high or too low, the conversion efficiency of CO ₂ will be insufficient, or the effect of selectively reducing CO ₂ to CO will be poor (for example, the content of CH ₄ in the product is too high).

在一些實施例中，上述觸媒更包括載體，且金屬氧化物負載於載體上。舉例來說，載體可為氧化鋯、氧化鈦、氧化矽、沸石、氧化鋁、其他合適載體、或上述之組合。在一些實施例中，金屬氧化物與載體的重量比為1:0.01至1:9。若載體的比例過高，則金屬氧化物含量過低導致CO ₂的轉換效率不足。 In some embodiments, the above catalyst further includes a carrier, and the metal oxide is supported on the carrier. For example, the support can be zirconia, titania, silica, zeolite, alumina, other suitable supports, or combinations thereof. In some embodiments, the weight ratio of metal oxide to support is 1:0.01 to 1:9. If the ratio of the carrier is too high, the metal oxide content is too low, resulting in insufficient conversion efficiency of _CO2 .

本揭露一實施例提供之選擇性還原CO ₂成CO的方法，包括：提供上述選擇性還原CO ₂成CO的觸媒；以及將H ₂與CO ₂與觸媒接觸，使CO ₂還原成CO。在一些實施例中，將H ₂與CO ₂與觸媒接觸的溫度為200℃至500℃。若上述步驟的溫度過低，則CO ₂的轉換效率不足或甚至不轉換。若上述步驟的溫度過高，則會增加製程能耗並增加碳排放量。在一些實施例中，將H ₂與CO ₂與觸媒接觸的壓力為1 bar至40 bar。若上述步驟的壓力過低，則產量(throughput)不足而不適於工業化。若上述步驟的壓力過高，則會增加製程能耗並增加碳排放量。 An embodiment of the present disclosure provides a method for selectively reducing CO ₂ to CO, including: providing the above-mentioned catalyst for selectively reducing CO ₂ to CO; and contacting H ₂ with CO ₂ and the catalyst to reduce CO ₂ to CO . In some embodiments, the temperature at which the H ₂ and CO ₂ are contacted with the catalyst is 200°C to 500°C. If the temperature of the above steps is too low, the conversion efficiency of _CO2 is insufficient or not even converted. If the temperature of the above steps is too high, it will increase the energy consumption of the process and increase the carbon emission. In some embodiments, the pressure at which the _H2 and _CO2 are contacted with the catalyst is 1 bar to 40 bar. If the pressure of the above steps is too low, the throughput will be insufficient and not suitable for industrialization. If the pressure of the above steps is too high, it will increase the energy consumption of the process and increase the carbon emission.

在一些實施例中，H ₂與CO ₂的莫耳比例為16:1至1:4。若H ₂的用量過高，則降低產物中CO的選擇性(比如CH ₄的產率提高)。若H ₂的用量過低，則無法有效轉換CO ₂。 In some embodiments, the molar ratio of H to _CO is 16: ₁ to 1:4. If the amount of H ₂ is too high, the selectivity of CO in the product is reduced (eg, the yield of CH ₄ is increased). If the amount of H ₂ is too low, CO ₂ cannot be efficiently converted.

值得注意的是，本揭露所提供的觸媒之金屬氧化物中，金屬元素如Fe、Co、及Mn的種類不可隨意置換。舉例來說，若將Co置換成Cu，則在低溫下(如≤500℃，甚或≤400℃)不具有高選擇性還原CO ₂成CO的效果。 It should be noted that, in the metal oxide of the catalyst provided by the present disclosure, the types of metal elements such as Fe, Co, and Mn cannot be arbitrarily replaced. For example, if Co is replaced by Cu, it does not have the effect of reducing CO ₂ to CO with high selectivity at low temperature (eg, ≤500°C, or even ≤400°C).

綜上所述，本揭露提供的觸媒可在低溫下有效轉換CO ₂，使其選擇性還原成CO而不產生CH ₄。與現有還原CO2成CO的製程相較，本揭露的製程溫度較低(比如可低至300℃以下)且產物中的CO選擇性較高，可有效降低製程能耗並節省分離成本(比如分離CO與CH ₄)。 To sum up, the catalyst provided by the present disclosure can effectively convert CO ₂ at low temperature, so that it can be selectively reduced to CO without generating CH ₄ . Compared with the existing process of reducing CO2 to CO, the process temperature of the present disclosure is lower (for example, it can be as low as 300° C. or less) and the selectivity of CO in the product is high, which can effectively reduce process energy consumption and save separation costs (such as separation costs). CO and CH ₄ ).

為讓本揭露之上述內容和其他目的、特徵、和優點能更明顯易懂，下文特舉出較佳實施例，作詳細說明如下： [實施例] In order to make the above-mentioned content and other objects, features, and advantages of the present disclosure more obvious and easy to understand, preferred embodiments are given below, and are described in detail as follows: [Example]

製備例1 (Fe _0.8Co _0.1Mn _0.1O _z) 將硝酸鐵(0.8 mol) 、硝酸鈷(0.1 mol)、與硝酸錳(0.1 mol)置於燒杯，加入水(200 mL)後於常溫下攪拌溶解。調整溶液pH值至中性。攪拌2小時後直接加熱至110℃使其乾燥。將乾燥後的固體加熱至450℃後煅燒4小時，以得金屬氧化物觸媒Fe _0.8Co _0.1Mn _0.1O _z。z為氧化配位數。 Preparation Example 1 (Fe _0.8 Co _0.1 Mn _0.1 O _z ) Put iron nitrate (0.8 mol), cobalt nitrate (0.1 mol), and manganese nitrate (0.1 mol) in a beaker, add water (200 mL), and stir at room temperature dissolve. Adjust the pH of the solution to neutral. After stirring for 2 hours, it was directly heated to 110°C and dried. The dried solid was heated to 450° C. and then calcined for 4 hours to obtain a metal oxide catalyst Fe _0.8 Co _0.1 Mn _0.1 O _z . z is the oxidation coordination number.

製備例2 (Fe _0.8Co _0.1Mn _0.1O _z) 將硝酸鈷(0.1 mol)與硝酸錳(0.1 mol)置於燒杯，加入水(200 mL)後於常溫下攪拌溶解。調整溶液pH值至中性。將氫氧化鐵(0.8 mol)加入溶液後攪拌使其均勻混合，攪拌2小時後直接加熱至110℃使其乾燥。將乾燥後的固體加熱至450℃後煅燒4小時，以得金屬氧化物觸媒Fe _0.8Co _0.1Mn _0.1O _z。z為氧化配位數。 Preparation Example 2 (Fe _0.8 Co _0.1 Mn _0.1 O _z ) Cobalt nitrate (0.1 mol) and manganese nitrate (0.1 mol) were placed in a beaker, water (200 mL) was added, and the mixture was stirred and dissolved at room temperature. Adjust the pH of the solution to neutral. Ferric hydroxide (0.8 mol) was added to the solution, and the solution was stirred to be uniformly mixed. After stirring for 2 hours, the solution was directly heated to 110° C. and dried. The dried solid was heated to 450° C. and then calcined for 4 hours to obtain a metal oxide catalyst Fe _0.8 Co _0.1 Mn _0.1 O _z . z is the oxidation coordination number.

製備例3 (Fe _0.7Co _0.2Mn _0.1O _z) 將硝酸鐵(0.7 mol) 、硝酸鈷(0.2 mol)、與硝酸錳(0.1 mol)置於燒杯，加入水(200 mL)後於常溫下攪拌溶解。調整溶液pH值至中性。攪拌2小時後直接加熱至110℃使其乾燥。將乾燥後的固體加熱至450℃後煅燒4小時，以得金屬氧化物觸媒Fe _0.7Co _0.2Mn _0.1O _z。z為氧化配位數。 Preparation Example 3 (Fe _0.7 Co _0.2 Mn _0.1 O _z ) Put iron nitrate (0.7 mol), cobalt nitrate (0.2 mol), and manganese nitrate (0.1 mol) in a beaker, add water (200 mL), and stir at room temperature dissolve. Adjust the pH of the solution to neutral. After stirring for 2 hours, it was directly heated to 110°C and dried. The dried solid was heated to 450° C. and then calcined for 4 hours to obtain a metal oxide catalyst Fe _0.7 Co _0.2 Mn _0.1 O _z . z is the oxidation coordination number.

製備例4 (Fe _0.9Co _0.01Mn _0.09O _z) 將硝酸鐵(0.9 mol) 、硝酸鈷(0.01 mol)、與硝酸錳(0.09 mol)置於燒杯，加入水(200 mL)後於常溫下攪拌溶解。調整溶液pH值至中性。攪拌2小時後直接加熱至110℃使其乾燥。將乾燥後的固體加熱至450℃後煅燒4小時，以得金屬氧化物觸媒Fe _0.9Co _0.01Mn _0.09O _z。z為氧化配位數。 Preparation Example 4 (Fe _0.9 Co _0.01 Mn _0.09 O _z ) Ferric nitrate (0.9 mol), cobalt nitrate (0.01 mol), and manganese nitrate (0.09 mol) were placed in a beaker, water (200 mL) was added, and the mixture was stirred at room temperature dissolve. Adjust the pH of the solution to neutral. After stirring for 2 hours, it was directly heated to 110°C and dried. The dried solid was heated to 450° C. and then calcined for 4 hours to obtain a metal oxide catalyst Fe _0.9 Co _0.01 Mn _0.09 O _z . z is the oxidation coordination number.

比較製備例1 (Fe _0.5Co _0.4Mn _0.1O _z) 將硝酸鐵(0.5 mol)、硝酸鈷(0.4 mol)、與硝酸錳(0.1 mol)置於燒杯，加入水(200 mL)後於常溫下攪拌溶解。調整溶液pH值至中性。攪拌2小時後直接加熱至110℃使其乾燥。將乾燥後的固體加熱至450℃後煅燒4小時，以得金屬氧化物觸媒Fe _0.5Co _0.4Mn _0.1O _z。z為氧化配位數。 Comparative Preparation Example 1 (Fe _0.5 Co _0.4 Mn _0.1 O _z ) Ferric nitrate (0.5 mol), cobalt nitrate (0.4 mol), and manganese nitrate (0.1 mol) were placed in a beaker, water (200 mL) was added, and the mixture was kept at room temperature. Stir to dissolve. Adjust the pH of the solution to neutral. After stirring for 2 hours, it was directly heated to 110°C and dried. The dried solid was heated to 450° C. and then calcined for 4 hours to obtain a metal oxide catalyst Fe _0.5 Co _0.4 Mn _0.1 O _z . z is the oxidation coordination number.

比較製備例2 (Fe _0.8Co _0.2O _z) 將硝酸鈷(0.2 mol)置於燒杯，加入水(200 mL)後於常溫下攪拌溶解，調整溶液pH值至中性。將氫氧化鐵(0.8 mol)加入溶液後攪拌使其均勻混合，攪拌2小時後直接加熱至110℃使其乾燥。將乾燥後的固體加熱至450℃後煅燒4小時，以得金屬氧化物觸媒Fe _0.8Co _0.2O _z。z為氧化配位數。 Comparative Preparation Example 2 (Fe _0.8 Co _0.2 O _z ) Cobalt nitrate (0.2 mol) was placed in a beaker, water (200 mL) was added, and the solution was stirred and dissolved at room temperature, and the pH value of the solution was adjusted to neutral. Ferric hydroxide (0.8 mol) was added to the solution, and the solution was stirred to be uniformly mixed. After stirring for 2 hours, the solution was directly heated to 110° C. and dried. The dried solid was heated to 450° C. and then calcined for 4 hours to obtain a metal oxide catalyst Fe _0.8 Co _0.2 O _z . z is the oxidation coordination number.

比較製備例3 (Fe _0.8Cu _0.1Mn _0.1O _z) 將硝酸鐵(0.8 mol)、硝酸銅(0.1 mol)、與硝酸錳(0.1 mol)置於燒杯，加入水(200 mL)後於常溫下攪拌溶解。調整溶液pH值至中性。攪拌2小時後直接加熱至110℃使其乾燥。將乾燥後的固體加熱至450℃後煅燒4小時，以得金屬氧化物觸媒Fe _0.8Cu _0.1Mn _0.1O _z。z為氧化配位數。 Comparative Preparation Example 3 (Fe _0.8 Cu _0.1 Mn _0.1 O _z ) Ferric nitrate (0.8 mol), copper nitrate (0.1 mol), and manganese nitrate (0.1 mol) were placed in a beaker, water (200 mL) was added, and the mixture was kept at room temperature. Stir to dissolve. Adjust the pH of the solution to neutral. After stirring for 2 hours, it was directly heated to 110°C and dried. The dried solid was heated to 450° C. and then calcined for 4 hours to obtain a metal oxide catalyst Fe _0.8 Cu _0.1 Mn _0.1 O _z . z is the oxidation coordination number.

比較製備例4 (Fe _0.8Mn _0.2O _z) 將硝酸錳(0.2 mol)置於燒杯，加入水(200 mL)後於常溫下攪拌溶解，調整溶液pH值至中性。將氫氧化鐵(0.8 mol，Alfa)加入溶液後攪拌使其均勻混合，攪拌2小時後直接加熱至110℃使其乾燥。將乾燥後的固體加熱至450℃後煅燒4小時，以得金屬氧化物觸媒Fe _0.8Mn _0.2O _z。z為氧化配位數。 Comparative Preparation Example 4 (Fe _0.8 Mn _0.2 O _z ) Manganese nitrate (0.2 mol) was placed in a beaker, water (200 mL) was added, and the solution was stirred and dissolved at room temperature, and the pH value of the solution was adjusted to neutral. Ferric hydroxide (0.8 mol, Alfa) was added to the solution, and the solution was stirred to be uniformly mixed. After stirring for 2 hours, the solution was directly heated to 110° C. and dried. The dried solid was heated to 450° C. and then calcined for 4 hours to obtain the metal oxide catalyst Fe _0.8 Mn _0.2 O _z . z is the oxidation coordination number.

實施例1 將製備例1的金屬氧化物觸媒Fe _0.8Co _0.1Mn _0.1O _z(20-30 mesh，6 mL)填入管柱中，將氫氣與二氧化碳(GHSV為800至1200hr ^-1)通入管柱以接觸金屬氧化物觸媒，控制管柱溫度並連續反應60分鐘後，以氣相層析法(搭配carboxen-1010 plot管柱)確認產物組成，如表1所示。由表1可知，製備例1的金屬氧化物觸媒在低溫下(300℃)的CO ₂轉化率接近理論值，且產物的CO選擇率極高。 Example 1 The metal oxide catalyst Fe _0.8 Co _0.1 Mn _0.1 O _z (20-30 mesh, 6 mL) of Preparation Example 1 was filled into a column, and hydrogen and carbon dioxide (GHSV: 800 to 1200 hr ^-1 ) were passed through. After entering the column to contact the metal oxide catalyst, controlling the column temperature and reacting continuously for 60 minutes, the product composition was confirmed by gas chromatography (with a carboxen-1010 plot column), as shown in Table 1. It can be seen from Table 1 that the CO ₂ conversion rate of the metal oxide catalyst of Preparation Example 1 at low temperature (300° C.) is close to the theoretical value, and the CO selectivity of the product is extremely high.

實施例2 與實施例1類似，差別在於將金屬氧化物觸媒改為製備例2的金屬氧化物觸媒Fe _0.8Co _0.1Mn _0.1O _z。其餘反應條件的控制方式與產物分析方法與實施例1相同，結果如表1所示。由表1可知，不同製備方式所形成的金屬氧化物觸媒Fe _0.8Co _0.1Mn _0.1O _z在低溫下(300℃)的CO ₂轉化率接近理論值，且產物的CO選擇率極高。 Example 2 Similar to Example 1, the difference is that the metal oxide catalyst is changed to the metal oxide catalyst of Preparation Example 2 Fe _0.8 Co _0.1 Mn _0.1 O _z . The control mode and product analysis method of the remaining reaction conditions are the same as those in Example 1, and the results are shown in Table 1. It can be seen from Table 1 that the CO ₂ conversion rate of the metal oxide catalyst Fe _0.8 Co _0.1 Mn _0.1 O _z formed by different preparation methods at low temperature (300 ° C) is close to the theoretical value, and the CO selectivity of the product is extremely high.

實施例3 與實施例1類似，差別在於將金屬氧化物觸媒改為製備例3的金屬氧化物觸媒Fe _0.7Co _0.2Mn _0.1O _z。其餘反應條件的控制方式與產物分析方法與實施例1相同，結果如表1所示。由表1可知，金屬氧化物觸媒Fe _0.7Co _0.2Mn _0.1O _z在低溫下(300℃)的CO ₂轉化率接近理論值，且產物的CO選擇率極高。 Example 3 Similar to Example 1, the difference is that the metal oxide catalyst is changed to the metal oxide catalyst of Preparation Example 3 Fe _0.7 Co _0.2 Mn _0.1 O _z . The control mode and product analysis method of the remaining reaction conditions are the same as those in Example 1, and the results are shown in Table 1. It can be seen from Table 1 that the CO ₂ conversion rate of the metal oxide catalyst Fe _0.7 Co _0.2 Mn _0.1 O _z at low temperature (300°C) is close to the theoretical value, and the CO selectivity of the product is extremely high.

實施例4 與實施例1類似，差別在於將金屬氧化物觸媒改為製備例4的金屬氧化物觸媒Fe _0.9Co _0.01Mn _0.09O _z。其餘反應條件的控制方式與產物分析方法與實施例1相同，結果如表1所示。由表1可知，金屬氧化物觸媒Fe _0.9Co _0.01Mn _0.09O _z在低溫下(400℃)的CO ₂轉化率接近理論值，且產物的CO選擇率極高。 Example 4 Similar to Example 1, the difference is that the metal oxide catalyst is changed to the metal oxide catalyst of Preparation Example 4 Fe _0.9 Co _0.01 Mn _0.09 O _z . The control mode and product analysis method of the remaining reaction conditions are the same as those in Example 1, and the results are shown in Table 1. It can be seen from Table 1 that the CO ₂ conversion rate of the metal oxide catalyst Fe _0.9 Co _0.01 Mn _0.09 O _z at low temperature (400°C) is close to the theoretical value, and the CO selectivity of the product is extremely high.

比較例1 與實施例1類似，差別在於將金屬氧化物觸媒改為比較製備例1的金屬氧化物觸媒Fe _0.5Co _0.4Mn _0.1O _z。其餘反應條件的控制方式與產物分析方法與實施例1相同，結果如表1所示。由表1可知，金屬氧化物觸媒Fe _0.5Co _0.4Mn _0.1O _z在低溫下(300℃)的CO ₂轉化率偏低，且產物的CO選擇率低。由此可知，Fe的比例過低且Co的比例過高的金屬氧化物觸媒，無法在低溫下有效地選擇性還原CO ₂成CO。 Comparative Example 1 Similar to Example 1, the difference is that the metal oxide catalyst of Comparative Preparation Example 1 is changed to Fe _0.5 Co _0.4 Mn _0.1 O _z . The control mode and product analysis method of the remaining reaction conditions are the same as those in Example 1, and the results are shown in Table 1. It can be seen from Table 1 that the CO ₂ conversion rate of the metal oxide catalyst Fe _0.5 Co _0.4 Mn _0.1 O _z at low temperature (300°C) is low, and the CO selectivity of the product is low. From this, it can be seen that a metal oxide catalyst with an excessively low proportion of Fe and an excessively high proportion of Co cannot efficiently selectively reduce CO ₂ to CO at low temperature.

比較例2 與實施例1類似，差別在於將金屬氧化物觸媒改為比較製備例2的金屬氧化物觸媒Fe _0.8Co _0.2O _z。其餘反應條件的控制方式與產物分析方法與實施例1相同，結果如表1所示。由表1可知，金屬氧化物觸媒Fe _0.8Co _0.2O _z在低溫下(300℃)的CO ₂轉化率偏低，且產物的CO選擇率低。由此可知，無Mn的金屬氧化物觸媒無法在低溫下有效地選擇性還原CO ₂成CO。 Comparative Example 2 is similar to Example 1, except that the metal oxide catalyst is changed to the metal oxide catalyst Fe _0.8 Co _0.2 O _z of Comparative Preparation Example 2. The control mode and product analysis method of the remaining reaction conditions are the same as those in Example 1, and the results are shown in Table 1. It can be seen from Table 1 that the CO ₂ conversion rate of the metal oxide catalyst Fe _0.8 Co _0.2 O _z at low temperature (300°C) is low, and the CO selectivity of the product is low. From this, it can be seen that the Mn-free metal oxide catalyst cannot selectively reduce _CO2 to CO efficiently at low temperature.

比較例3 與實施例1類似，差別在於將金屬氧化物觸媒改為比較製備例3的金屬氧化物觸媒Fe _0.8Cu _0.1Mn _0.1O _z。其餘反應條件的控制方式與產物分析方法與實施例1相同，結果如表1所示。由表1可知，金屬氧化物觸媒Fe _0.8Cu _0.1Mn _0.1O _z在低溫下(300℃)的CO ₂轉化率偏低，且產物中仍含有少量的CH ₄。由此可知，將Fe _0.8Co _0.1Mn _0.1O _z的Co置換成Cu的金屬氧化物觸媒無法在低溫下有效還原CO ₂成CO。 Comparative Example 3 is similar to Example 1, except that the metal oxide catalyst is changed to the metal oxide catalyst of Comparative Preparation Example 3 Fe _0.8 Cu _0.1 Mn _0.1 O _z . The control mode and product analysis method of the remaining reaction conditions are the same as those in Example 1, and the results are shown in Table 1. It can be seen from Table 1 that the CO ₂ conversion rate of the metal oxide catalyst Fe _0.8 Cu _0.1 Mn _0.1 O _z at low temperature (300°C) is low, and the product still contains a small amount of CH ₄ . From this, it can be seen that the metal oxide catalyst that replaces Co of Fe _0.8 Co _0.1 Mn _0.1 O _z with Cu cannot effectively reduce CO ₂ to CO at low temperature.

比較例4 與實施例1類似，差別在於將金屬氧化物觸媒改為氫氧化鐵。其餘反應條件的控制方式與產物分析方法與實施例1相同，結果如表1所示。由表1可知，氫氧化鐵在低溫下(400℃)的CO ₂轉化率偏低，且產物中含有大量的CH ₄。由此可知，氫氧化鐵無法在低溫下有效還原CO ₂成CO。 Comparative Example 4 was similar to Example 1, except that the metal oxide catalyst was changed to iron hydroxide. The control mode and product analysis method of the remaining reaction conditions are the same as those in Example 1, and the results are shown in Table 1. It can be seen from Table 1 that the CO ₂ conversion rate of iron hydroxide at low temperature (400° C.) is low, and the product contains a large amount of CH ₄ . From this, it can be seen that ferric hydroxide cannot effectively reduce _CO2 to CO at low temperature.

比較例5 與實施例1類似，差別在於將金屬氧化物觸媒改為比較製備例4的金屬氧化物觸媒Fe _0.8Mn _0.2O _z。其餘反應條件的控制方式與產物分析方法與實施例1相同，結果如表1所示。由表1可知，金屬氧化物觸媒Fe _0.8Mn _0.2O _z在低溫下(400℃)的CO ₂轉化率偏低。由此可知，金屬氧化物觸媒Fe _0.8Mn _0.2O _z無法在低溫下有效還原CO ₂成CO。 Comparative Example 5 is similar to Example 1, the difference is that the metal oxide catalyst of Comparative Preparation Example 4 is changed to Fe _0.8 Mn _0.2 O _z . The control mode and product analysis method of the remaining reaction conditions are the same as those in Example 1, and the results are shown in Table 1. It can be seen from Table 1 that the CO ₂ conversion rate of the metal oxide catalyst Fe _0.8 Mn _0.2 O _z is low at low temperature (400°C). From this, it can be seen that the metal oxide catalyst Fe _0.8 Mn _0.2 O _z cannot effectively reduce CO ₂ to CO at low temperature.

表1 金屬氧化物觸媒 H ₂/CO 反應溫度(℃) 反應壓力(bar) 理論平衡轉化率(%,以CO ₂為基準) CO ₂轉化率(%) 選擇率(%) CO CH ₄ 實施例1 製備例1 (Fe _0.8Co _0.1Mn _0.1O _z) 1 200 10 6.1 3.23 100 ND 250 9.6 7.16 100 ND 300 13.6 13.19 100 ND 實施例2 製備例2 (Fe _0.8Co _0.1Mn _0.1O _z) 2 250 1 13.4 10.2 100 ND 300 19.0 19.0 100 ND 實施例3 製備例3 (Fe _0.7Co _0.2Mn _0.1O _z) 2 200 1 8.6 5.4 100 ND 300 19.0 17.4 100 ND 400 31.1 30.1 100 ND 實施例4 製備例4 Fe _0.9Co _0.01Mn _0.09O _z 2 400 1 31.1 29.2 100 ND 500 42.5 41.9 100 ND 比較例1 比較製備例1 (Fe _0.5Co _0.4Mn _0.1O _z) 1 250 1 9.6 3.8 85.4 14.6 300 13.6 10.9 32.4 67.6 比較例2 比較製備例2 (Fe _0.8Co _0.2O _z) 1 300 1 13.6 4.87 78.2 21.8 5 13.6 7.85 43.3 56.7 10 13.6 9.77 26.3 73.7 比較例3 比較製備例3 (Fe _0.8Cu _0.1Mn _0.1O _z) 2 250 1 13.4 5.0 86.3 13.7 300 19.0 10.8 97.6 2.4 比較例4 氫氧化鐵 2 300 1 19.0 2.5 87.4 12.6 400 31.1 4.3 87.9 12.1 比較例5 比較製備例4 (Fe _0.8Mn _0.2O _z) 2 300 1 19.0 3.4 100 ND 400 31.1 7.8 100 ND ND:感測不到 Table 1 Metal oxide catalyst H ₂ /CO Reaction temperature (℃) Reaction pressure (bar) Theoretical Equilibrium Conversion Rate (%, based on CO ₂ ) CO ₂ conversion rate (%) Selectivity (%) CO CH ₄ Example 1 Preparation Example 1 (Fe _0.8 Co _0.1 Mn _0.1 O _z ) 1 200 10 6.1 3.23 100 ND 250 9.6 7.16 100 ND 300 13.6 13.19 100 ND Example 2 Preparation Example 2 (Fe _0.8 Co _0.1 Mn _0.1 O _z ) 2 250 1 13.4 10.2 100 ND 300 19.0 19.0 100 ND Example 3 Preparation Example 3 (Fe _0.7 Co _0.2 Mn _0.1 O _z ) 2 200 1 8.6 5.4 100 ND 300 19.0 17.4 100 ND 400 31.1 30.1 100 ND Example 4 Preparation Example 4 Fe _0.9 Co _0.01 Mn _0.09 O _z 2 400 1 31.1 29.2 100 ND 500 42.5 41.9 100 ND Comparative Example 1 Comparative Preparation Example 1 (Fe _0.5 Co _0.4 Mn _0.1 O _z ) 1 250 1 9.6 3.8 85.4 14.6 300 13.6 10.9 32.4 67.6 Comparative Example 2 Comparative Preparation Example 2 (Fe _0.8 Co _0.2 O _z ) 1 300 1 13.6 4.87 78.2 21.8 5 13.6 7.85 43.3 56.7 10 13.6 9.77 26.3 73.7 Comparative Example 3 Comparative Preparation Example 3 (Fe _0.8 Cu _0.1 Mn _0.1 O _z ) 2 250 1 13.4 5.0 86.3 13.7 300 19.0 10.8 97.6 2.4 Comparative Example 4 Ferric hydroxide 2 300 1 19.0 2.5 87.4 12.6 400 31.1 4.3 87.9 12.1 Comparative Example 5 Comparative Preparation Example 4 (Fe _0.8 Mn _0.2 O _z ) 2 300 1 19.0 3.4 100 ND 400 31.1 7.8 100 ND ND: not sensed

製備例5 (Fe _0.8Co _0.1Mn _0.1O _z/ZrO ₂) 將硝酸鐵(0.8 mol) 、硝酸鈷(0.1 mol)、與硝酸錳(0.1 mol)置於燒杯，加入水(200 mL)後於常溫下攪拌溶解。調整溶液pH值至中性。將氧化鋯粉體(200 g)加入溶液，攪拌2小時後直接加熱至110℃使其乾燥。將乾燥後的固體加熱至450℃後煅燒4小時，以得負載於氧化鋯上的金屬氧化物觸媒Fe _0.8Co _0.1Mn _0.1O _z/ZrO ₂。z為氧化配位數。金屬氧化物與氧化鋯的重量比為1:2.2。 Preparation Example 5 (Fe _0.8 Co _0.1 Mn _0.1 O _z /ZrO ₂ ) Ferric nitrate (0.8 mol), cobalt nitrate (0.1 mol), and manganese nitrate (0.1 mol) were placed in a beaker, and water (200 mL) was added to the Stir and dissolve at room temperature. Adjust the pH of the solution to neutral. Zirconium oxide powder (200 g) was added to the solution, and after stirring for 2 hours, it was directly heated to 110° C. and dried. The dried solid was heated to 450° C. and then calcined for 4 hours to obtain a metal oxide catalyst Fe _0.8 Co _0.1 Mn _0.1 O _z /ZrO ₂ supported on zirconia. z is the oxidation coordination number. The weight ratio of metal oxide to zirconia was 1:2.2.

製備例6 (Fe _0.8Co _0.1Mn _0.1O _z/Al ₂O ₃) 將硝酸鐵(0.4 mol) 、硝酸鈷(0.05 mol)、與硝酸錳(0.05 mol)置於燒杯，加入水(200 mL)後於常溫下攪拌溶解。調整溶液pH值至中性。將氧化鋁粉體(200 g)加入溶液，攪拌2小時後直接加熱至110℃使其乾燥。將乾燥後的固體加熱至450℃後煅燒4小時，以得負載於氧化鋁上的金屬氧化物觸媒Fe _0.8Co _0.1Mn _0.1O _z/Al ₂O ₃。z為氧化配位數。金屬氧化物與氧化鋁的重量比為1:4.5。 Preparation Example 6 (Fe _0.8 Co _0.1 Mn _0.1 O _z /Al ₂ O ₃ ) Ferric nitrate (0.4 mol), cobalt nitrate (0.05 mol), and manganese nitrate (0.05 mol) were placed in a beaker, and water (200 mL) was added Then, it was stirred and dissolved at room temperature. Adjust the pH of the solution to neutral. Alumina powder (200 g) was added to the solution, and after stirring for 2 hours, it was directly heated to 110° C. and dried. The dried solid was heated to 450° C. and then calcined for 4 hours to obtain a metal oxide catalyst Fe _0.8 Co _0.1 Mn _0.1 O _z /Al ₂ O ₃ supported on alumina. z is the oxidation coordination number. The weight ratio of metal oxide to alumina was 1:4.5.

製備例7 (Fe _0.8Co _0.1Mn _0.1O _z/TiO ₂) 將硝酸鐵(0.2 mol) 、硝酸鈷(0.025 mol)、與硝酸錳(0.025 mol)置於燒杯，加入水(200 mL)後於常溫下攪拌溶解。調整溶液pH值至中性。將氧化鈦粉體(200 g)加入溶液，攪拌2小時後直接加熱至110℃使其乾燥。將乾燥後的固體加熱至450℃後煅燒4小時，以得負載於氧化鈦上的金屬氧化物觸媒Fe _0.8Co _0.1Mn _0.1O _z/TiO ₂。z為氧化配位數。金屬氧化物與氧化鈦的重量比為1:9。 Preparation Example 7 (Fe _0.8 Co _0.1 Mn _0.1 O _z /TiO ₂ ) Ferric nitrate (0.2 mol), cobalt nitrate (0.025 mol), and manganese nitrate (0.025 mol) were placed in a beaker, and water (200 mL) was added to the Stir and dissolve at room temperature. Adjust the pH of the solution to neutral. Titanium oxide powder (200 g) was added to the solution, and after stirring for 2 hours, it was directly heated to 110° C. and dried. The dried solid was heated to 450° C. and then calcined for 4 hours to obtain a metal oxide catalyst Fe _0.8 Co _0.1 Mn _0.1 O _z /TiO ₂ supported on titanium oxide. z is the oxidation coordination number. The weight ratio of metal oxide to titanium oxide was 1:9.

製備例8 (Fe _0.8Co _0.1Mn _0.1O _z/沸石) 將硝酸鐵(0.2 mol) 、硝酸鈷(0.025 mol)、與硝酸錳(0.025 mol)置於燒杯，加入水(200 mL)後於常溫下攪拌溶解。調整溶液pH值至中性。將Y型沸石粉體(200 g)加入溶液，攪拌2小時後直接加熱至110℃使其乾燥。將乾燥後的固體加熱至450℃後煅燒4小時，以得負載於沸石上的金屬氧化物觸媒Fe _0.8Co _0.1Mn _0.1O _z/沸石。z為氧化配位數。金屬氧化物與沸石的重量比為1:9。 Preparation Example 8 (Fe _0.8 Co _0.1 Mn _0.1 O _z / zeolite) Put iron nitrate (0.2 mol), cobalt nitrate (0.025 mol), and manganese nitrate (0.025 mol) in a beaker, add water (200 mL), and store at room temperature Stir to dissolve. Adjust the pH of the solution to neutral. Y-type zeolite powder (200 g) was added to the solution, and after stirring for 2 hours, it was directly heated to 110° C. and dried. The dried solid was heated to 450° C. and then calcined for 4 hours to obtain a metal oxide catalyst Fe _0.8 Co _0.1 Mn _0.1 O _z /zeolite supported on zeolite. z is the oxidation coordination number. The weight ratio of metal oxide to zeolite was 1:9.

實施例5 將製備例5的觸媒Fe _0.8Co _0.1Mn _0.1O _z/ZrO ₂(20-30 mesh，3 mL)填入管柱中，將氫氣與二氧化碳(GHSV為800至1200hr ^-1)通入管柱以接觸觸媒，控制管柱溫度並連續反應60分鐘後，以氣相層析法(搭配carboxen-1010 plot管柱)確認產物組成，如表2所示。由表2可知，Fe _0.8Co _0.1Mn _0.1O _z/ZrO ₂在低溫下(400℃)的CO ₂轉化率接近理論值，且產物的CO選擇率極高。 Example 5 The catalyst Fe _0.8 Co _0.1 Mn _0.1 O _z /ZrO ₂ (20-30 mesh, 3 mL) of Preparation Example 5 was filled into a column, and hydrogen and carbon dioxide (GHSV: 800 to 1200 hr ^-1 ) were passed through. After entering the column to contact the catalyst, controlling the column temperature and reacting continuously for 60 minutes, the product composition was confirmed by gas chromatography (with a carboxen-1010 plot column), as shown in Table 2. It can be seen from Table 2 that the CO ₂ conversion of Fe _0.8 Co _0.1 Mn _0.1 O _z /ZrO ₂ at low temperature (400°C) is close to the theoretical value, and the CO selectivity of the product is extremely high.

實施例6 與實施例5類似，差別在於將觸媒改為製備例6的負載於氧化鋁上的金屬氧化物觸媒Fe _0.8Co _0.1Mn _0.1O _z/Al ₂O ₃。其餘反應條件的控制方式與產物分析方法與實施例5相同，結果如表2所示。由表2可知，Fe _0.8Co _0.1Mn _0.1O _z/Al ₂O ₃在低溫下(300℃)的CO ₂轉化率接近理論值，且產物的CO選擇率高。 Example 6 Similar to Example 5, the difference is that the catalyst is changed to the metal oxide catalyst supported on alumina of Preparation Example 6 Fe _0.8 Co _0.1 Mn _0.1 O _z /Al ₂ O ₃ . The control mode and product analysis method of the remaining reaction conditions are the same as in Example 5, and the results are shown in Table 2. It can be seen from Table 2 that the CO ₂ conversion rate of Fe _0.8 Co _0.1 Mn _0.1 O _z /Al ₂ O ₃ at low temperature (300°C) is close to the theoretical value, and the CO selectivity of the product is high.

實施例7 與實施例5類似，差別在於將觸媒改為製備例7的負載於氧化鈦上的金屬氧化物觸媒Fe _0.8Co _0.1Mn _0.1O _z/TiO ₂。其餘反應條件的控制方式與產物分析方法與實施例5相同，結果如表2所示。由表2可知，Fe _0.8Co _0.1Mn _0.1O _z/TiO ₂在低溫下(400℃)的CO ₂轉化率接近理論值，且產物的CO選擇率極高。此外，Fe _0.8Co _0.1Mn _0.1O _z/TiO ₂在高溫高壓下的反應條件下，仍有高CO ₂轉化率且產物的CO選擇率極高。 Example 7 Similar to Example 5, the difference is that the catalyst is changed to the metal oxide catalyst supported on titanium oxide of Preparation Example 7 Fe _0.8 Co _0.1 Mn _0.1 O _z /TiO ₂ . The control mode and product analysis method of the remaining reaction conditions are the same as in Example 5, and the results are shown in Table 2. It can be seen from Table 2 that the CO ₂ conversion of Fe _0.8 Co _0.1 Mn _0.1 O _z /TiO ₂ at low temperature (400 °C) is close to the theoretical value, and the CO selectivity of the product is extremely high. In addition, Fe _0.8 Co _0.1 Mn _0.1 O _z /TiO ₂ still has high CO ₂ conversion and extremely high CO selectivity of the product under the reaction conditions of high temperature and high pressure.

實施例8 與實施例5類似，差別在於將觸媒改為製備例8的負載於沸石上的金屬氧化物觸媒Fe _0.8Co _0.1Mn _0.1O _z/沸石。其餘反應條件的控制方式與產物分析方法與實施例5相同，結果如表2所示。由表2可知，Fe _0.8Co _0.1Mn _0.1O _z/沸石在低溫下(300℃)的CO ₂轉化率接近理論值，且產物的CO選擇率高。 Example 8 Similar to Example 5, the difference is that the catalyst is changed to the metal oxide catalyst supported on zeolite of Preparation Example 8 Fe _0.8 Co _0.1 Mn _0.1 O _z /zeolite. The control mode and product analysis method of the remaining reaction conditions are the same as in Example 5, and the results are shown in Table 2. It can be seen from Table 2 that the CO ₂ conversion rate of Fe _0.8 Co _0.1 Mn _0.1 O _z /zeolite at low temperature (300°C) is close to the theoretical value, and the CO selectivity of the product is high.

表2 金屬氧化物觸媒 H ₂/CO 反應溫度(℃) 反應壓力(bar) 理論平衡轉化率(%,以CO ₂為基準) CO ₂轉化率(%) 選擇率(%) CO CH ₄ 實施例5 製備例5 (Fe _0.8Co _0.1Mn _0.1O _z/ZrO ₂) 2 250 1 13.4 6.5 100 ND 300 19.0 16.5 100 ND 350 25.0 23.8 100 ND 400 31.1 31.0 100 ND 實施例6 製備例6 (Fe _0.8Co _0.1Mn _0.1O _z/Al ₂O ₃) 0.25 300 1 6.5 6.0 99.5 0.5 1 13.6 11.4 98.3 1.7 2 19.0 16.7 94.4 5.6 實施例7 製備例7 (Fe _0.8Co _0.1Mn _0.1O _z/TiO ₂) 2 300 1 19.0 4.4 100 ND 400 1 31.1 26.1 100 ND 400 30 31.1 29.8 100 ND 500 1 42.5 35.2 100 ND 實施例8 製備例8 (Fe _0.8Co _0.1Mn _0.1O _z/沸石) 4 300 1 26.1 26.5 94.5 5.5 400 41.7 35.2 98.1 1.9 ND:感測不到 Table 2 Metal oxide catalyst H ₂ /CO Reaction temperature (℃) Reaction pressure (bar) Theoretical Equilibrium Conversion Rate (%, based on CO ₂ ) CO ₂ conversion rate (%) Selectivity (%) CO CH ₄ Example 5 Preparation Example 5 (Fe _0.8 Co _0.1 Mn _0.1 O _z /ZrO ₂ ) 2 250 1 13.4 6.5 100 ND 300 19.0 16.5 100 ND 350 25.0 23.8 100 ND 400 31.1 31.0 100 ND Example 6 Preparation Example 6 (Fe _0.8 Co _0.1 Mn _0.1 O _z /Al ₂ O ₃ ) 0.25 300 1 6.5 6.0 99.5 0.5 1 13.6 11.4 98.3 1.7 2 19.0 16.7 94.4 5.6 Example 7 Preparation Example 7 (Fe _0.8 Co _0.1 Mn _0.1 O _z /TiO ₂ ) 2 300 1 19.0 4.4 100 ND 400 1 31.1 26.1 100 ND 400 30 31.1 29.8 100 ND 500 1 42.5 35.2 100 ND Example 8 Preparation Example 8 (Fe _0.8 Co _0.1 Mn _0.1 O _z /zeolite) 4 300 1 26.1 26.5 94.5 5.5 400 41.7 35.2 98.1 1.9 ND: not sensed

實施例9 與實施例5類似，差別在於改變H ₂/CO的氣體空間速度(GHSV)。其餘反應條件的控制方式與產物分析方法與實施例5相同，結果如表3所示。由表3可知，高氣體空間速度的CO ₂轉化率會降低，但高氣體空間速度單位觸媒量所產出的CO量仍高於低氣體空間流速所產出的CO量(CO kg/kg觸媒)。至於未轉換的CO ₂與H ₂可再次導入觸媒以選擇性還原成CO。此外，產物的CO選擇率極高。 Example 9 Similar to Example 5, except that the gas space velocity (GHSV) of _H2 /CO was changed. The control mode and product analysis method of the remaining reaction conditions are the same as in Example 5, and the results are shown in Table 3. It can be seen from Table 3 that the _CO conversion rate of high gas space velocity will decrease, but the amount of CO produced per unit catalyst amount at high gas space velocity is still higher than that produced by low gas space velocity (CO kg/kg). catalyst). The unconverted CO ₂ and H ₂ can be re-introduced into the catalyst for selective reduction to CO. In addition, the CO selectivity of the product is extremely high.

表3 金屬氧化物觸媒 H ₂/CO 反應溫度(℃) 反應壓力(bar) 氣體空間速度(GHSV, h ^-1) 理論平衡轉化率(%,以CO ₂為基準) CO ₂轉化率(%) 選擇率(%) CO CH ₄ 製備例5 (Fe _0.8Co _0.1Mn _0.1O _z/ZrO ₂) 2 400 1 800 31.1 26.5 100 ND 1600 26.0 100 ND 3200 26.8 100 ND 6400 25.8 100 ND 12800 24.7 100 ND 22400 23.4 100 ND ND:感測不到 table 3 Metal oxide catalyst H ₂ /CO Reaction temperature (℃) Reaction pressure (bar) Gas space velocity (GHSV, h ^-1 ) Theoretical Equilibrium Conversion Rate (%, based on CO ₂ ) CO ₂ conversion rate (%) Selectivity (%) CO CH ₄ Preparation Example 5 (Fe _0.8 Co _0.1 Mn _0.1 O _z /ZrO ₂ ) 2 400 1 800 31.1 26.5 100 ND 1600 26.0 100 ND 3200 26.8 100 ND 6400 25.8 100 ND 12800 24.7 100 ND 22400 23.4 100 ND ND: not sensed

實施例10 將製備例7的觸媒Fe _0.8Co _0.1Mn _0.1O _z/TiO ₂(20-30 mesh，100 mL)填入管柱中，將氫氣與二氧化碳(GHSV為5000 h ^-1)通入管柱以接觸觸媒，控制管柱溫度並連續反應60分鐘後，以氣相層析法(搭配carboxen-1010 plot管柱)確認產物組成，如表4所示。由表4可知，H ₂/CO的比例過高或溫度過高，會降低CO的選擇性(CH ₄的產率提高)。 Example 10 The catalyst Fe _0.8 Co _0.1 Mn _0.1 O _z /TiO ₂ (20-30 mesh, 100 mL) of Preparation Example 7 was filled into a column, and hydrogen and carbon dioxide (GHSV: 5000 h ^-1 ) were passed into the tube After the column was contacted with catalyst, the column temperature was controlled and the reaction was continued for 60 minutes, and the product composition was confirmed by gas chromatography (with a carboxen-1010 plot column), as shown in Table 4. It can be seen from Table 4 that if the ratio of H ₂ /CO is too high or the temperature is too high, the selectivity of CO will be reduced (the yield of CH ₄ will increase).

表4 金屬氧化物觸媒 H ₂/CO 反應溫度(℃) 反應壓力(bar) 理論平衡轉化率(%,以CO ₂為基準) CO ₂轉化率(%) 產物(%) CO ₂ H ₂ CO H ₂O CH ₄ 製備例7 (Fe _0.8Co _0.1Mn _0.1O _z/TiO ₂) 2.0 500 13.8 42.5 41.0 19.7 53.0 13.7 13.7 ND 3.2 51.2 51.9 11.5 63.8 12.2 12.4 ND 4.0 55.4 55.5 8.9 68.9 11.1 11.1 0.1 5.3 60.7 58.5 6.6 74.8 9.3 9.3 0.1 8.0 68.2 66.2 3.8 81.5 7.4 7.4 0.2 8.0 600 78.1 75.0 2.8 79.6 8.2 8.2 1.2 ND:感測不到 Table 4 Metal oxide catalyst H ₂ /CO Reaction temperature (℃) Reaction pressure (bar) Theoretical Equilibrium Conversion Rate (%, based on CO ₂ ) CO ₂ conversion rate (%) product(%) CO ₂ H ₂ CO H ₂ O CH ₄ Preparation Example 7 (Fe _0.8 Co _0.1 Mn _0.1 O _z /TiO ₂ ) 2.0 500 13.8 42.5 41.0 19.7 53.0 13.7 13.7 ND 3.2 51.2 51.9 11.5 63.8 12.2 12.4 ND 4.0 55.4 55.5 8.9 68.9 11.1 11.1 0.1 5.3 60.7 58.5 6.6 74.8 9.3 9.3 0.1 8.0 68.2 66.2 3.8 81.5 7.4 7.4 0.2 8.0 600 78.1 75.0 2.8 79.6 8.2 8.2 1.2 ND: not sensed

實施例11 將製備例7的觸媒Fe _0.8Co _0.1Mn _0.1O _z/TiO ₂(20-30 mesh，100 mL)填入管柱中，將氫氣與二氧化碳(GHSV為5000 h ^-1)通入管柱以接觸觸媒，控制管柱溫度並連續反應60分鐘後，以氣相層析法(搭配carboxen-1010 plot管柱)確認產物組成，如表5所示。由表5可知，在400℃下，產物具有高CO選擇性。至於未反應的H ₂，可與CO ₂混合後再次導入觸媒以形成CO。 Example 11 The catalyst Fe _0.8 Co _0.1 Mn _0.1 O _z /TiO ₂ (20-30 mesh, 100 mL) of Preparation Example 7 was filled into a column, and hydrogen and carbon dioxide (GHSV: 5000 h ^-1 ) were passed into the tube After the column was contacted with catalyst, the column temperature was controlled and the reaction was continued for 60 minutes, and the product composition was confirmed by gas chromatography (with a carboxen-1010 plot column), as shown in Table 5. It can be seen from Table 5 that the product has high CO selectivity at 400 °C. As for the unreacted H ₂ , it can be mixed with CO ₂ and then introduced into the catalyst again to form CO.

表5 金屬氧化物觸媒 H ₂/CO 反應溫度(℃) 反應壓力(bar) 理論平衡轉化率(%,以CO ₂為基準) CO ₂轉化率(%) 產物(%) CO ₂ H ₂ CO H ₂O CH ₄ 製備例7 (Fe _0.8Co _0.1Mn _0.1O _z/TiO ₂) 2.0 400 13.8 31.1 31 23.0 56.3 10.3 10.3 ND 3.2 38.1 36.6 15.1 67.5 8.7 8.7 ND 4.0 41.7 41.5 11.7 71.7 8.3 8.3 ND 5.3 46.4 46.5 8.5 76.7 7.4 7.4 ND 8.0 53.7 52.7 5.3 83.0 5.9 5.9 ND 16.0 65.9 65.7 2.0 90.3 3.9 3.9 ND ND:感測不到 table 5 Metal oxide catalyst H ₂ /CO Reaction temperature (℃) Reaction pressure (bar) Theoretical Equilibrium Conversion (%, based on CO ₂ ) CO ₂ conversion rate (%) product(%) CO ₂ H ₂ CO H ₂ O CH ₄ Preparation Example 7 (Fe _0.8 Co _0.1 Mn _0.1 O _z /TiO ₂ ) 2.0 400 13.8 31.1 31 23.0 56.3 10.3 10.3 ND 3.2 38.1 36.6 15.1 67.5 8.7 8.7 ND 4.0 41.7 41.5 11.7 71.7 8.3 8.3 ND 5.3 46.4 46.5 8.5 76.7 7.4 7.4 ND 8.0 53.7 52.7 5.3 83.0 5.9 5.9 ND 16.0 65.9 65.7 2.0 90.3 3.9 3.9 ND ND: not sensed

雖然本揭露已以數個較佳實施例揭露如上，然其並非用以限定本揭露，任何所屬技術領域中具有通常知識者，在不脫離本揭露之精神和範圍內，當可作任意之更動與潤飾，因此本揭露之保護範圍當視後附之申請專利範圍所界定者為準。Although the present disclosure has been disclosed above with several preferred embodiments, it is not intended to limit the present disclosure. Anyone with ordinary knowledge in the technical field may make any changes without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the appended patent application.

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Claims

一種選擇性還原CO ₂成CO的觸媒，包括：一金屬氧化物，其化學式為Fe _xCo _yMn _(1-x-y)O _z；其中0.7≤x≤0.95，0.01≤y≤0.25，且z為氧化配位數。 A catalyst for selectively reducing CO ₂ to CO, comprising: a metal oxide whose chemical formula is Fe _x Co _y Mn _(1-xy) O _z ; wherein 0.7≤x≤0.95, 0.01≤y≤0.25, and z is the oxidation coordination number.

如請求項1之選擇性還原CO ₂成CO的觸媒，更包括一載體，且該金屬氧化物負載於該載體上。 The catalyst for selectively reducing CO ₂ to CO as claimed in claim 1 further comprises a carrier, and the metal oxide is supported on the carrier.

如請求項2之選擇性還原CO ₂成CO的觸媒，其中該載體包括氧化鋯、氧化鈦、氧化矽、沸石、氧化鋁、或上述之組合。 The catalyst for selective reduction of CO ₂ to CO as claimed in claim 2, wherein the carrier comprises zirconia, titania, silica, zeolite, alumina, or a combination thereof.

如請求項2之選擇性還原CO ₂成CO的觸媒，其中該金屬氧化物與該載體的重量比為1:0.01至1:9。 The catalyst for selectively reducing CO ₂ to CO as claimed in claim 2, wherein the weight ratio of the metal oxide to the support is 1:0.01 to 1:9.

一種選擇性還原CO ₂成CO的方法，包括：提供請求項1之選擇性還原CO ₂成CO的觸媒；以及將H ₂與CO ₂與該觸媒接觸，使CO ₂還原成CO。 A method for selectively reducing _CO2 to CO, comprising: providing a catalyst for selectively reducing _CO2 to CO according to claim 1; and contacting _H2 and _CO2 with the catalyst to reduce _CO2 to CO.

如請求項5之選擇性還原CO ₂成CO的方法，其中將H ₂與CO ₂與該觸媒接觸的溫度為200℃至500℃。 The method for selectively reducing CO ₂ to CO as claimed in claim 5, wherein the temperature at which H ₂ and CO ₂ are brought into contact with the catalyst is 200°C to 500°C.

如請求項5之選擇性還原CO ₂成CO的方法，其中將H ₂與CO ₂與該觸媒接觸的壓力為1 bar至40 bar。 The method for selectively reducing CO ₂ to CO as claimed in claim 5, wherein the pressure for contacting H ₂ and CO ₂ with the catalyst is 1 bar to 40 bar.

如請求項5之選擇性還原CO ₂成CO的方法，其中H ₂與CO ₂的莫耳比例為16:1至1:4。 The method for selectively reducing CO ₂ to CO as claimed in claim 5, wherein the molar ratio of H ₂ to CO ₂ is 16:1 to 1:4.