Synergistic adsorption and activation of nickel phthalocyanine anchored onto ketjenblack for CO2 electrochemical reduction

Abstract

Designing a facile and high-yield strategy to prepare highly active and selective electrocatalysts for CO2 reduction is beneficial to the industrial application. However, there are still many challenges in catalyst preparation. Besides, further mechanism studies on catalytic process for enhancing CO2 reduction are not clear. Herein, We have found that nickel phthalocyanine facilely incorporated into defect-rich ketjenblack by π-π stacking method can greatly improve its ECR performance. Nickel phthalocyanine/ketjenblack compounds show high selectivity and activity, 251 times turnover frequency for converting CO2 to CO compared to pristine nickel phthalocyanine, and keep above FECO of 90% under large potentials regions from −0.65 to −1.05 V vs RHE. Fundamentally density functional theory (DFT) calculations reveal that nickel phthalocyanine molecules anchored onto ketjenblack enhance the electron acceptability, decreasethe formation energy of the *COOH and inhibit the rival hydrogen evolution reaction (HER), thus showing extremely high synergistic catalytic properties in ECR.