Advancing hydrogen peroxide electro-generation: Selective production at high rates in a flow-through module

Electrochimica Acta, vol. 497, pp. 144533

Abstract

Electrochemical synthesis of hydrogen peroxide (H2O2) via oxygen reduction reactions (ORR) represents a green, environmentally friendly, and decentralized alternative to the conventional, fossil-based, and centralized anthraquinone process. This work presents a flow-through module using commercial carbon black (CB) as a catalyst at current densities of up to 120 mA cm−2. Acid treatment of CB increases its oxygen content, leading to Faraday efficiency (FE) values above 80 % with a maximum specific H2O2 production rate of 64.3 mg cm−2 h−1. Additionally, the effect of catalyst loading on the functionality of a gas diffusion electrode (GDE) at 120 mA cm−2 and over long-term electrolysis (7.5 h) is investigated, discussing the detrimental penetration of electrolyte into the GDE due to the enhanced electro-wetting, which shifts the three-phase boundary toward the gas channel side. This study underscores the critical significance of optimizing the parameters involved in GDE fabrication, especially under high current densities and extended operational periods, propelling our understanding towards the development of a robust flow-through module for the electro-generation of H2O2.

Authors 4

1. Mojtaba Mohseni Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University, Aachener Verfahrenstechnik - Chemical Process Engineering, Forckenbeckstr. 51, 52074 Aachen, Germany

2. Waralee Dilokekunakul Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University, Aachener Verfahrenstechnik - Chemical Process Engineering, Forckenbeckstr. 51, 52074 Aachen, Germany

3. Matthias Weßling Aachen DWI - Leibniz Institute for Interactive Materials

   DWI – Leibniz Institute for Interactive Materials · RWTH Aachen University

   Affiliation as printed

   DWI - Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52074 Aachen, Germany

   RWTH Aachen University, Aachener Verfahrenstechnik - Chemical Process Engineering, Forckenbeckstr. 51, 52074 Aachen, Germany

4. Robert Keller corresponding Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University, Aachener Verfahrenstechnik - Chemical Process Engineering, Forckenbeckstr. 51, 52074 Aachen, Germany