工業革命後全球二氧化碳及其他溫室氣體之人為排放量大幅增加，造成全球暖化(Global Warming)。因此，如何有效地降低人為二氧化碳的排放量已成為近年來各國努力的目標。碳捕捉、再利用與封存(Carbon Capture, Utilization and Storage, CCUS)為目前各國積極開發的減碳技術，其中將二氧化碳轉化為有用之產物為碳再利用之一環，包括合成氣、甲醇及尿素等。本研究旨在研發具良好活性之觸媒，並與電漿反應器結合為一複合式反應器，應用於轉換CO2/CH4為液態產物程序，並分為三個階段：(一)研發同時具二氧化碳和甲烷轉化活性之觸媒、(二)開發觸媒電漿系統，並藉兩者之協同作用嘗試轉化為液態產物如醋酸和甲醇、(三)經由觸媒物化分析探討其反應機制，提升液態產物之選擇性。結果表明，電漿觸媒法具有轉化二氧化碳為單一液態產物之可行性，Cu/Al2O3 和Ni/Al2O3對於乙酸具有較高選擇性；而In/Al2O3對於甲醇具有較高選擇性，其甲醇選擇性可達20%，且In/Al2O3無論在熱催化或是電漿反應中皆表現出較佳之穩定性，另外In含量為8-10%時具有較佳之甲醇選擇性。而探討反應過程中所消耗之能源以及產物所能提供之能源時可發現，電漿觸媒系統對於二氧化碳之轉換能效較低，但由於可共同轉化全球化潛勢較高之甲烷，因此仍有助於溫室氣體減排。且液態產物具有成為能源來源之潛力，亦可作為另類儲能方式幫助能源轉型，故此法具有潛力幫助國內及全球之溫室氣體減量工作，同時為能源轉型提供一可行方向。;Since the industrial revolution, the global anthropogenic emissions of carbon dioxide and other greenhouse gases has been increasing significantly, causing global warming. Therefore, how to effectively reduce the emission of anthropogenic carbon dioxide has become the goal of many countries in recent years. Carbon Capture, Utilization and Storage (CCUS) is a carbon reduction technology actively developed by various countries. Conversion of carbon dioxide into useful products including synthesis gas, methanol and urea is one of the carbon recycling approach. This study aims to develop a catalyst with good activity and combine it with a plasma reactor as a hybrid system for the conversion of CO2/CH4 into a liquid product and the study is divided into three stages: (1) Preparation of the catalyst for the conversion of carbon dioxide and methane, (2) Development of a catalytic plasma system to convert CO2/CH4 into liquid products such as acetic acid and methanol. (3) Elucidation of mechanism through catalytic physicochemical analysis and enhancement of selectivity. The results show that the plasma catalysis has the feasibility of converting CO2 and CH4 into a single liquid product. Cu/Al2O3 and Ni/Al2O3 have higher selectivity to acetic acid, while In/Al2O3 has a higher selectivity to methanol. In/Al2O3 exhibits better stability in both thermal and plasma reactions. Regarding the energy consumption of the process, it can be found that the energy efficiency of converting CO2 and CH4 is still low, but the liquid product has the potential as an energy source, so this method is still feasible and contributes to domestic and global greenhouse gas reduction work.
