Direct reduction of diluted CO2 gas to C2 products by copper hydroxyphosphate microrods

Abstract

AbstractElectrochemical reduction of CO2 is widely researched in recent years. However, direct electro‐reduction of diluted CO2 to C2 products is seldomly studied. In this work, electrocatalytic reduction of CO2 with different concentrations were conducted on Cu2(PO4)(OH) catalysts. The catalytic performance in diluted CO2 is comparable with that in pure CO2 by using Cu2(PO4)(OH) as catalyst. Besides, the selectivity of C2 product is still as high as 64.6% in 50%CO2 concentration. The normalized C2 current density of Cu2(PO4)(OH) was over 6.8 times higher than that of commonly used Cu2O–Cu catalyst with similar size. In situ Raman spectroscopy proved that Cu+ is the main active site at higher potentials. More importantly, a higher local pH is realized under diluted CO2 test conditions which is favorable for promoting C–C coupling. Finally, in situ ATR‐FTIR spectroscopy was performed to further monitor and identify the adsorbed intermediates and help reveal the mechanism for the catalysts.