Coupling regulation of boron doping and morphology in nano-floral CuO using one pot method for electrocatalytic CO2 reduction

Abstract

The two crucial methods for regulating Cu-based electrocatalysts to achieve high C2+ selectivity during CO2 reduction are doping with heteroatoms and controlling morphology. However, it is challenging to achieve both through the facial preparation approach. Herein, we prepared a series of nano-floral boron-doped CuO catalysts by a simple one-pot template-free approach to attain the coupling regulation of boron doping and morphology by the amount of H3BO3 added. As indicated by the SEM and TEM results, these petals of B3-CuO are the sharpest and the overall size is the smallest among all the nano-floral catalysts, enabling them to demonstrate a tip effect. B3-CuO exhibits enhanced electron transport capacity and a more pronounced response to CO2, aligning with its electrochemical characteristics. Meanwhile, B3-CuO possesses higher Vo compared to other catalysts. These factors lead to B3-CuO having the greatest FEC2H4 at −1.2 V vs. RHE, reaching 51.2 %, and excellent stability. The possible reaction pathway of Bx-CuO has been elucidated through in-situ ATR-SEIRAS, which indicates that the mechanism involves CO2→*COOH→*CO→*OCCOH → C2H4. Therefore, the coupled use of B-doped and morphology regulation offers a notable improvement in C2H4 selectivity while unlocking asymmetric C–C coupled pathways towards higher FEC2H4.