Simultaneous Generation of H2O2 and Formate by Co‐Electrolysis of Water and CO2 over Bifunctional Zn/SnO2 Nanodots

Abstract

AbstractHydrogen peroxide (H2O2) and formate are important chemicals used in various chemical manufacturing industries. One promising approach for the simultaneous production of these chemicals is coupling anodic two‐electron water oxidation with cathodic CO2 reduction in an electrolyzer using nonprecious bifunctional electrocatalysts. Herein, we report an innovative hybrid electrosynthesis strategy using Zn‐doped SnO2 (Zn/SnO2) nanodots as bifunctional redox electrocatalysts to achieve Faradaic efficiencies of 80.6 % and 92.2 % for H2O2 and formate coproduction, respectively, along with excellent stability for at least 60 h at a current density of ≈150 mA cm−2. Through a combination of physicochemical characterizations, including operando attenuated total reflectance‐Fourier transform infrared spectroscopy (ATR‐FTIR), isotope labeling mass spectrometry (MS)/1H NMR and quasi‐in situ electron paramagnetic resonance (EPR), with density functional theory (DFT) calculations, we discovered that the Zn dopant facilitates the coupling of *OH intermediates to promote H2O2 production and optimizes the adsorption of *OCHO intermediates to accelerate formate formation. Our findings offer new insights into designing more efficient bifunctional electrocatalyst‐based pair‐electrosynthesis system for the coproduction of H2O2 and formate feedstocks.