Preparation and electrocatalytic CO₂ reduction of Ni-based single-atom catalyst

Electrocatalytic CO₂ reduction reaction (CO₂ RR) has great application potential in solving global warming and the energy crisis, but the current problems such as low catalytic efficiency and diverse catalytic products limit the commercial application of CO₂ RR reaction. A series of nickel single-atom catalysts with different nickel contents were prepared by a one-pot carbonization method. The morphology, structure, atomic valence state, and metal content of nickel single-atom catalysts were characterized by XRD, XPS, ICP-OES, HRTEM, HAADF-STEM, XAS and other methods. The electrocata lytic performance was evaluated by the Faradaic efficiency(FE) and current density(J) of the electrocatalytic reduction products. The electrocatalytic performance was improved by changing the electrolysis experimental device. The experimental results indicated that both FE_CO and J_CO increased as the Ni metal loading of Ni single-atom catalysts increased. Zn₁ Ni₂-CN in the catalyst exhibited excellent CO₂ RR catalytic performance. In the H-type electrolytic cell, the FE_CO reached 89% at-0. 7 V vs. RHE, and the J_CO reached 6. 99 mA·cm^-2 at-0. 9 V vs. RHE. From-0. 4 to-1. 2 V vs. RHE in the flow electrolytic cell, FE_CO remained above 99%, and J_CO reached 174. 5 mA·cm^-2 at-1. 2 V vs. RHE.