High-Performance Electrocatalytic Carbon Dioxide Reduction to Formic Acid on Cypress-Like Enzyme-Antimony-Bismuth Biohybrid.

Electrocatalytic carbon dioxide (CO2) reduction reaction (CO2RR) to valuable liquid fuels offers a promising solution for global warming. The challenges of low CO2 delivery and poor product selectivity hinder the practical application of CO2RR technology. This study proposes electrocatalytic CO2-to-formic acid (HCOOH) conversion using a cypress-like carbonic anhydrase/antimony-decorated bismuth (CA/Sb-decorated Bi) biohybrid. The carbonic anhydrase (CA) as CO2 shuttle can enrich CO2 concentration on the electrode surface, accelerating the CO2 hydration kinetics and reaction rate. Density functional theory (DFT) calculations indicate that the introduction of Sb can alter the adsorption energy of H* and HCOO*, which is beneficial for CO2RR to form HCOOH. Besides, CA/Sb-decorated Bi biohybrid can suppress competitive hydrogen evolution reactions (HER). Consequently, the CA/Sb-decorated Bi biohybrid achieves the Faradaic efficiency of 93.41% and 100% selectivity for HCOOH at -1.3 V. This work demonstrates the application potential of enzyme modification and metal decorating in CO2RR for the development of sustainable energy.