Enhanced Electroconversion CO₂‐to‐Formate by Oxygen‐Vacancy‐Rich Ultrasmall Bi‐Based Catalyst Over a Wide Potential Window

Abstract

Bi-based materials quickly rise as promising candidates for electrochemical CO 2 -to-formate conversion. However, most of them only display a narrow potential range for the desired formate selectivity. Herein, we designed an oxygen-vacancy-rich ultrasmall bismuth subcarbonate supported on reduced graphene oxide composite (Vo-BOC/G) for electrochemical CO 2 -toformate conversion. The Vo-BOC/G exhibits an outstanding formate selectivity up to 100 % at À 1.2 V vs. RHE and an impressive partial current density of 38 mA cm À 2 in 0.1 M KHCO 3 . More importantly, the considerable formate selectivity (> 80 %) was obtained over an impressively wide potential range of 600 mV, superior over most of reported Bi-based electrocatalysts under the same conditions. Theoretical results show the abundant Vo defects significantly lower energy barrier for *CO 2 formation, resulting in high formate selectivity over a wider potential window. This work may pave the way for Bibased materials application in different renewable energyconversion devices.

Bismuth‐Based Electrocatalysts for Identical Value‐Added Formic Acid Through Coupling CO2 Reduction and Methanol Oxidation

“…[ 24 ] In the high‐resolution spectrum of O1s, the peaks at 529.5, 530.94, and 531.9 eV correspond to Bi─O, oxygen vacancy, and adsorbed water, respectively (Figure 1C). [ 25–27 ] The peak for oxygen vacancies gradually becomes stronger as the interface electron density increases (Figure 1B,C). The phenomenon was also confirmed by electron spin resonance (EPR) (Figure S3, Supporting Information).…”

Clean Synthesis of Bismuth Porous Nanosheets for Efficient CO2 Electroreduction

“…(b) FEs in the potential range from −0.8 to −1.8 V vs RHE. (c) Potential windows with FE HCOO– over 80% of the Bi NPSs and other Bi based catalysts reported in literature. ,,− (d) Long-term stability test of Bi PNSs at −1.0 V vs RHE for 10 h.…”

Electro‐Synthesis of Organic Compounds with Heterogeneous Catalysis

“…The combination of oxygen‐vacancy‐rich Bi subcarbonate with reduced graphene oxide (Vo‐BOC/G) has been designed for eCO 2 RR‐to‐formate conversion. [ 212 ] Using 0.1 m KHCO 3 , the Vo‐BOC/G shows 100% formate selectivity at −1.2 V versus RHE and boasts a partial current density of 38 mA cm −2 . It has been shown that the abundant V o defects lower the energy barrier for * CO 2 formation, which results in high formate selectivity.…”