銅銀雙金屬奈米觸媒上的二氧化碳還原反應

Abstract

藉由電化學二氧化碳還原反應(CO2RR)，可以轉化廢氣二氧化碳作為高經濟價值的燃料如一氧化碳，此反應已被長遠的研究並且確實可以有效地解決溫室效應與能源短缺的問題。在這次的研究，我們合成銅核-銀殼的奈米觸媒並運用於二氧化碳還原反應。還原劑、反應溫度與銅銀比例皆是在製程中可以提升CO2RR 效能的關鍵變因。適當的反應溶劑需要添加三正辛基膦(TOP)以及油酸(OA)，並在483 K 下進行。通過比例的調整，Cu2Ag1 具有最佳的產物選擇性，電位-1.3 V 下的CO 法拉第效率為70.0%，其電流密度為-3.98 mA/cm2。根據能量散射光譜儀(EDX)、X 光繞射分析儀(XRD)和X 光光電子光譜儀(XPS)結果，Cu2Ag1 具有明確的核殼結構，殼層還有豐富的銀金屬態，這些被視為是影響產物選擇性之原因。CO2 reduction (CO2RR), which converts contaminated CO2 into potential fuel of CO, has been widely studied to better solve the problems of green-house effect and energy shortage. In our present work, CuAg bimetallic nanocatalysts have been synthesized and utilized in CO2RR application. The key synthetic parameters of reduction reagents, temperatures and Cu/Ag ratios have been thoroughly optimized to better enhance the efficiency of CO2RR. The results showed that the reagent of mixed trioctylphosphine (TOP) and oleic acid (OA), the temperature of 483 K and the ratio of Cu2Ag1 demonstrate the best CO Faradaic efficiency of 70.0% under -1.3 V (V vs. RHE), which current density of -3.98 mA/cm2. According to the characterizations from Energy Dispersive X-Ray Analysis (EDX), X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), the optimized catalyst shows the appropriate core-shell structure with abundant metallic state Ag in the shell, which are responsible for the excellent CO2RR performance.