Nickel phthalocyanine based porous bimetallic catalysts for high activity CO2 electroreduction over wide potential window

Abstract

Robust electrocatalyst with high catalytic activity and high selectivity over wide potential window is a crucial element for CO₂ electroreduction. In this study, combining the advantages of metal-nitrogen-carbon catalyst and bimetallic atomic catalyst, nickel phthalocyanine based porous bimetallic catalyst was synthesized using various porous carbon supports. Benefit from the complementary and synergistic effect of dual active metals derived from nickel and copper, prepared bimetallic catalyst achieved high selectivity and CO Faradaic efficiency (FE_CO) exceeding 90% over a wide cathodic potential range (-0.57 V to -1.07 V), along with high current density and good long-term stability in CO₂ reduction (ECR) under low overpotential conditions of 464 millivolts. Besides, different carbon source carriers (citric acid, carbon, and ZIF-8) supported bimetallic catalyst were detailed, and the citric acid derived carbon source carrier fabricated bimetallic catalyst exhibited best performances with a highest current density (114.2 mA cm⁻² at -1.1 V) and a wide cathodic potential range (-0.57 V to -1.07 V) for FE_CO>90%. This work provides a cost-effective, extendable, and efficient strategy to fabricate electrocatalyst for CO₂ reduction to CO, which can meaningfully extend the CO₂ electroreduction in practical application.