Cu-CuOx/rGO catalyst derived from hybrid LDH/GO with enhanced C2H4 selectivity by CO2 electrochemical reduction

Abstract

Electrochemical CO2 conversion to value-added fuels and chemicals enabled by suitable heterogeneous catalysts has attained great attention given its economic viability and overall process efficiency. Herein, we have designed a new electro-catalyst ER-Cu5-LDH/rGO using electro-reduction method from Cu5Al-CO3 hybrid LDH/GO precursor for efficient CO2 reduction reaction (CO2RR). Interestingly, the ER-Cu5-LDH/rGO catalyst presented a higher C2H4 production selectivity than the ER-Cu5-LDH catalyst without rGO. The obtained ER-Cu5-LDH/rGO exhibited a high C2H4 faradaic efficiency (FE) up to 54 % and a high C2H4 partial current density of ‒11.64 mA/cm2 at ‒1.2 V vs. RHE. It also exhibited excellent stability up to 50 h. The total FE of gaseous and liquid products for ER-Cu5-LDH/rGO is closed to 100 %. The morphological changes during CO2RR were monitored using SEM analyses for catalyst stability examination. The influence of electrolyte or pH on the electro-catalytic performance of ER-Cu5-LDH/rGO were studied. In order to reflect the superiority of LDH precursors, a control catalyst containing Cu2O supported on rGO (ER-Cu2O/rGO) was prepared and comparatively studied. Overall, our hybrid catalyst system ER-Cu5-LDH/rGO is very promising materials for CO2 conversion to C2H4, displaying remarkable FE, high C2H4 partial current density, and the excellent stability. Such a commendable behavior is ascribed to the excellent dispersion of active copper species as well as the superior electric conductivity of rGO.