非再生能源已被使用很長一段時間，因為原料穩定性高以及成本低，人們多仰賴非再生能源供應日常所需，自工業革命以來化石燃料大量消耗，導致大氣中二氧化碳濃度快速上升，加劇全球溫室效應，因此二氧化碳還原的研究日漸重要。
本實驗主要透過類沸石咪唑骨架 (Zeolitic imidazolate framework-8, ZIF-8) 合成雙金屬之單原子觸媒，選擇銅與鈷作為雙金屬期望將二氧化碳還原為C2產物，並探討不同比例的銅與鈷前驅物對合成的影響，前驅物比例選擇基準選用類沸石咪唑骨架合成中的金屬中心-鋅，合成類沸石咪唑骨架後以高溫煅燒950 ℃ 得到氮摻雜碳結構。
實驗中透過掃描式電子顯微鏡 (Scanning electron microscope, SEM) 觀察到類沸石咪唑骨架的菱形十二面體結構，並從X光繞射分析 (X-ray diffraction, XRD)證明類沸石咪唑骨架成功合成，進行高溫煅燒後類沸石咪唑骨架移除，以X光吸收光譜 (XAS) 方法證實銅與鈷形成單原子觸媒分散於氮摻雜碳結構中，結構分析方面以XPS計算四種存在於氮摻雜碳的結構比例，試圖分析不同樣品在二氧化碳電催化還原中的效能差異，透過電化學方法結合氣相層析儀 (Gas chromatography, GC)、核磁共振儀 (Nuclear Magnetic Resonance, NMR) 分析產物分佈，研究可能的反應機制，發現鈷容易吸附*CO2並反應至*CO，接著銅進行C-C耦合反應，提升乙醇法拉第效率，最後以XAS分析反應前後的樣品，發現-0.6 V反應21小時後Cu、Co仍維持單原子觸媒型態。

Fossil fuels have been used for an extended period because of their high stability and low cost. People rely on non-renewable energy supplies for daily needs. It causes a rapid increase in atmospheric CO2 concentration and aggravates global warming. Therefore, it is mandatory and urgent to take action.
This experiment subject is to synthesize di-atomic single atom sites via a zeolite imidazole framework. It is envisaged that Copper and Cobalt as heterogeneous electrocatalysts will reduce CO2 to valuable C2 products by taking advantage of the synergetic coupling. Different ratios of Copper and Cobalt in the synthesis process were prepared. The ratio was determined based on zinc in the zeolite imidazole framework. The precursors were calcinated at 950 ℃ to obtain a nitrogen-doped carbon structure (NC).
From the scanning electron microscope (SEM) measurements, we observed a rhombic dodecahedron structure in the final samples, typical ZIF-8 morphology. We proved that the ZIF-8 structure was formed successfully by X-ray diffraction (XRD). Further, the ZIF-8 template was removed, then copper and cobalt were successfully dispersed to single atomic sites in NC type after pyrolysis. The characteristic single-atom was confirmed by X-ray absorption spectroscopy (XAS). Four NC structures were present and studied by XPS, and their effects in electrocatalysis were also discussed. The electrochemical CO2RR of different samples were tested, and their corresponding product distribution was measured by the electrochemical method, GC, and NMR to propose some possible reaction mechanisms. It is found that *CO2 adsorbed on cobalt reacts to *CO, then the C-C coupling takes place on Cu, so the faradaic efficiency of ethanol increases vis such a hetero-diatomic synergy. Finally, we used XAS to identify the sample structure difference before and after the reaction. Cu and Co remain single atoms after continuously applying -0.6 V for 21 Hr.

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