Enhanced Electrochemical CO2 Reduction Using Nonthermal Plasma: Insights into Pd Catalyst Reactivation and Precise Control of H2O2 for Improved CO2 Reduction Reaction Activity

Abstract

This study investigates the electrochemical reduction of CO₂ on Pd/C with in situ-generated H₂O₂ through low-temperature nonthermal plasma. Catalyst deactivation, a common challenge in CO₂ conversion, is addressed by leveraging the oxidizing environment created by H₂O₂. Experimental studies using linear sweep voltammetry and cyclic voltammetry demonstrate significantly improved CO₂ reduction activity during plasma discharge, correlated with an enlarged hydrogen desorption peak. Multicomponent physics-based computational simulation highlights the role of H₂O₂, a long-lived species, in enhancing CO₂ reduction. Formic acid is identified as a major liquid product, validated by nuclear magnetic resonance. The presence of H₂O₂ prevents CO poisoning on Pd surfaces, and H₂O₂ electroreduction alters hydrogen sorption, potentially creating an active PdH_x phase for effective CO₂ reduction. The study demonstrates the precise control of H₂O₂ concentration through nonthermal plasma, offering insights into Pd catalyst reactivation and improved CO₂ reduction activity. These findings contribute to the understanding of electrochemical CO₂ reduction mechanisms and provide a basis for optimizing catalytic processes in the presence of H₂O₂.