Enabling Direct H2O2 Production in Acidic Media through Rational Design of Transition Metal Single Atom Catalyst
Journal
Chem
Journal Volume
6
Journal Issue
3
Pages
658-674
Date Issued
2020
Author(s)
Gao, Jiajian et al.
Abstract
Hydrogen peroxide is a valuable chemical with extensive applications, but the current industrial production method is energy-intensive and generates substantial waste. The electrochemical oxygen reduction reaction in acidic media offers an attractive route for direct hydrogen peroxide generation and on-site applications. Unfortunately, there is still a lack of cost-effective electrocatalysts with high catalytic performance. Here, by combining theoretical calculations and experimental methods, we demonstrate that an atomically dispersed cobalt anchored in nitrogen-doped carbon can function as a highly active and selective electrocatalyst for direct hydrogen peroxide synthesis. This cobalt single-atom catalyst combines the advantages of both homogeneous catalysts of cobalt macrocycles (well-defined active sites) and heterogeneous metal-nitrogen-carbon catalysts (high catalytic performance) together, showing promising application in electrosynthesis device. ? 2019By combining theoretical and experimental methods, Gao et al. systematically studied the relationship between the structure of transition metal (Mn, Fe, Co, Ni, and Cu) single-atom catalyst anchored in nitrogen-doped graphene and the catalytic performance of hydrogen peroxide (H2O2) synthesis via electrochemical two-electron oxygen reduction reaction (ORR) (2e? ORR). The thus designed Co single-atom catalyst can function as a highly active and selective catalyst for H2O2 synthesis and even slightly outperforms state-of-the-art noble-metal-based electrocatalysts in acidic media. ? 2019The electrochemical oxygen reduction reaction in acidic media offers an attractive route for direct hydrogen peroxide (H2O2) generation and on-site applications. Unfortunately there is still a lack of cost-effective electrocatalysts with high catalytic performance. Here, we theoretically designed and experimentally demonstrated that a cobalt single-atom catalyst (Co SAC) anchored in nitrogen-doped graphene, with optimized adsorption energy of the *OOH intermediate, exhibited a high H2O2 production rate, which even slightly outperformed the state-of-the-art noble-metal-based electrocatalysts. The kinetic current of H2O2 production over Co SAC could reach 1 mA/cmdisk 2 at 0.6 V versus reversible hydrogen electrode in 0.1 M HClO4 with H2O2 faraday efficiency > 90%, and these performance measures could be sustained for 10 h without decay. Further kinetic analysis and operando X-ray absorption study combined with density functional theory (DFT) calculation demonstrated that the nitrogen-coordinated single Co atom was the active site and the reaction was rate-limited by the first electron transfer step. ? 2019
Subjects
catalyst design; electrocatalysis; hydrogen peroxide; oxygen reduction reaction; SDG7: Affordable and clean energy; SDG9: Industry, innovation, and infrastructure; single atom catalyst
Type
journal article