Copper-Bridge-Enhanced <i>p</i>-Band Center Modulation of Carbon-Bismuth Heterojunction for CO<sub>2</sub> Electroreduction.

Wang, Xiaoshan; Zhou, Minjun; Wang, Mingwang; Wang, Wenhang; Yang, Zhongxue; Zhang, Yunlong; Li, Qiang; Ning, Hui et al. · Nano Lett · 2023

basic_science · Level V

Where this comes from

Abstract

Bismuth-based catalysts have advanced CO<sub>2</sub> electroreduction to formic acid, but their intrinsic electronic structure remains a key obstacle to achieving a high catalytic performance. Herein, a copper bridge strategy is proposed to enhance electronic modulation effects in bismuth/carbon composites. Density functional theory calculations prove the novel <i>p-d-p</i> hybrid orbitals on the carbon-copper-bismuth heterojunction structure (Bi-Cu/HMCS) could stabilize the HCOO* intermediate and lower the thermodynamic barrier from CO<sub>2</sub> to formic acid. With the rapid electron-supplying effect of "copper bridge", the faradaic efficiency of formate reaches 100% (±2%) at a low overpotential of 500 mV and remains above 90% within a wide potential range. Using a solid-state electrolyte device, pure 0.6 M HCOOH is produced at a stable current density of 100 mA cm<sup>-2</sup> within 7.5 h, boasting an impressive energy efficiency of 53.8%. This work offers a new strategy for optimizing electronic structure of metal/carbon composite electrocatalysts.