Direct reduction of diluted <scp>CO<sub>2</sub></scp> gas to <scp>C<sub>2</sub></scp> products by copper hydroxyphosphate microrods
Ying Zhang, Yunliang Liu, Qing Yu, Qiankang Zhang, Zhanbo Si, Haitao Li, Hui Xu
Abstract
Abstract Electrochemical reduction of CO 2 is widely researched in recent years. However, direct electro‐reduction of diluted CO 2 to C 2 products is seldomly studied. In this work, electrocatalytic reduction of CO 2 with different concentrations were conducted on Cu 2 (PO 4 )(OH) catalysts. The catalytic performance in diluted CO 2 is comparable with that in pure CO 2 by using Cu 2 (PO 4 )(OH) as catalyst. Besides, the selectivity of C 2 product is still as high as 64.6% in 50%CO 2 concentration. The normalized C 2 current density of Cu 2 (PO 4 )(OH) was over 6.8 times higher than that of commonly used Cu 2 O–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 CO 2 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.