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.