Electroreduction of CO2 on polycrystalline copper: Effect of temperature on product selectivity

摘要: Abstract In this paper, we investigate the effect of temperature on product selectivity for electrochemical reduction carbon dioxide (CO2) polycrystalline copper (Cu). We show that an electrolyte solution can influence several reaction parameters in CO2 (CO2RR), including pH (both local and bulk), concentration dissolved ([CO2]), resistance, rate diffusion reactants to electrode surface, adsorbed intermediates. The working potential was −1.60 V vs. Ag/AgCl allow direct comparison with literature values. Under optimal conditions at 2 °C, faradaic efficiency (FE) converting methane (CH4) a Cu electrocatalyst increases ca. 50% while ethylene (C2H4) decreases 10%. Above room temperature, production hydrogen gas (H2) dominates reaction, reaching >50% FE. major products (i.e., >5% FE) observed all temperatures studied were H2, CH4, C2H4, monoxide, formate, driven by changes [CO2] rather than pH. Our initial goal confirm dependence CO2RR different temperatures. Importantly, discovered varies minimally over range (2 °C 42 °C), contrast corresponding selectivity.