Electrocatalytic Syngas Production Using Metalloporphyrins with Controllable H2/CO Ratios

Abstract

Electrochemical methods to produce syngas present a promising strategy for energy conservation and environmental protection. The H₂/CO ratio of syngas is crucial for its applications. However, few catalysts can achieve catalytic generation of syngas that can be directly used because the H₂/CO ratio is difficult to be controlled. To address this issue, bicomponent electrocatalysts are utilized to produce syngas with controllable H₂/CO ratios. These two catalysts in the bicomponent electrocatalysts can efficiently and selectively catalyze CO₂ reduction reaction (CO₂RR) to generate CO and hydrogen evolution reaction (HER) to generate H₂ respectively. Metalloporphyrins are promising electrocatalysts for both CO₂RR and HER. A series of metalloporphyrins 1-M (M = Fe, Co, Ni, Cu) were synthesized as electrocatalysts to produce syngas with different H₂/CO ratios. Among these metalloporphyrins, 1-Co and 1-Cu can selectively produce CO and H₂, respectively, through CO₂RR and HER in KHCO₃ aqueous solutions. The ratio of 1-Co and 1-Cu in bicomponent electrocatalysts 1-Co/1-Cu is adjusted to achieve the regulation of H₂/CO ratio (0.1–6.4) at high catalytic currents. This work provides a new approach for designing more efficient syngas catalysts with tunable H₂/CO ratios.