In–Bi bimetallic nanofibers with controllable crystal facets for high-rate electrochemical reduction of CO2 to formate

Abstract

Electrocatalytic carbon dioxide (CO₂) reduction reactions (ECO₂RRs) to form formate with high faradaic efficiency (FE) and production rate by renewable electricity are ideal to control CO₂ concentration in the atmosphere. In this work, we successfully prepared bimetallic Bi_xIn_y nanofiber (NF) catalysts with interconnected 3D network structure and controllable growth direction of crystal facets via electrospinning and the following electrochemical reduction for the first time, rendering a significantly increased InBi (200) lattice plane proportion in Bi₅In₅ NFs, which facilitated the improvement of intrinsic catalytic activity and formate selectivity for ECO₂RR catalysts, as evidenced by crystalline characterization and DFT calculations. Consequently, the obtained Bi₅In₅ NFs achieve a maximum FE of 96.8% for formate and the corresponding production rate can reach 4.55 mmol h⁻¹ cm⁻², superior to most of the formate producing catalysts. This work provides a novel approach for preparing bimetallic catalyst NFs with high FE and product selectivity; moreover, the favorable productivity brings substantial application potential in industrial production.