Efficient and stable electrocatalytic reduction of CO₂ by ZIF-8 composites

Electrocatalytic CO2 reduction reaction (eCO(2)RR) is still limited by the intrinsic activity and mass transfer of catalysts, resulting in low catalytic activity and high reaction onset potential. Herein, we explored the eCO(2)RR performance of zeolite imidazole framework (ZIF-8) with different sizes. We took ZIF-8 with a particle size of 50 nm as the research object, and further introduced carbon nanotubes (CNT) as the conductive substrate material. The hierarchical porous structure and hydrophobic interface of ZIF-8-50@ CNT were constructed by in-situ growth. The results of eCO(2)RR experiment showed that the introduction of CNT improved the conductivity of the catalyst, and the optimized composite effectively reduced the onset potential of the reaction. At -1.1 V (versus reversible hydrogen electrode (RHE)), the partial CO current density of ZIF-8-50@ CNT was 15.6 mA center dot cm(-2), and the catalyst surface activity of ZIF-8-50@CNT catalyst is increased by 3.5 times that of ZIF-8-50, and the Tafel slope was reduced to 136 mV center dot dec(-1). The selectivity and stability of the product CO were improved, and the Faraday efficiency (FE) of CO remained 80% at -0.9--1.2 V (vs RHE). In the 10 h stability test, the catalyst remained stable. The overall eCO(2)RR performance of catalyst was enhanced.