《Mater. Horiz.》: Confined CO in sandwich structure promotes C-C coupling in electrocatalytic CO₂ reduction

Wenya Fan,⁺ Yinghuan Liu,⁺ Chengbin Zhang,⁺ Xiangdong Chen, Dongpo He, Mengqian Li, Qing Hu, Xingchen Jiao,^* Qingxia Chen,^*and 

Yi Xie

Microenvironment regulation nearby catalyst surface plays a critical role in heterogeneous electrocatalytic reactions. The local concentration of reactants and intermediates significantly affects the reaction kinetics and product selectivity. Herein, we innovatively proposed to utilize the spatial confinement effect in sandwich structured C/Cu/C assembly to regulate the kinetic mass transport during the electrocatalytic CO₂ reduction reaction. The sandwich C/Cu/C assembly catalyst was successfully prepared via a simple bidirectional freezing and freeze-drying method. The sandwich structure changes the free diffusion pathway of CO intermediate within the sandwich interlayer and helps confine CO with locally increased CO concentration nearby catalyst surface, which in turn promotes the C–C coupling and thus improve the reaction activity and double the C₂ product selectivity compared to its disordered mixture counterpart. This kinetics regulation in sandwich structure may provide a new insight into the catalyst design and inspire the understanding of structure-performance relationship in electrocatalysis.

Figure 1. Schematic diagram of mass transport in sandwich C/Cu/C.