A sulfite/air fuel cell for H2O2 electrosynthesis

Abstract

H₂O₂ electrosynthesis is a promising alternative to the industry-dominant anthraquinone process. Unfortunately, currently, it suffers from high energy consumption. In this work, we couple the sulfite oxidation reaction with the 2e⁻ route oxygen reduction reaction to operate as a self-driven sulfite/air fuel cell for H₂O₂ electrosynthesis. An Au–Pd/C catalyst is synthesized as an H₂O₂ electrosynthesis catalyst, which exhibits good 2e⁻ route oxygen reduction reaction activity and selectivity. The fuel cell can realize an open cell voltage of 0.52 V and a discharge current density of 24.48 mA cm⁻² at 0 V. Ammonia desulphurization wastewater is chosen as the fuel, which can achieve both H₂O₂ electrosynthesis cost reduction and recycling of energy and resources from waste. A long-term test demonstrates the feasibility of the sulfite/air fuel cell, which can produce electricity and H₂O₂ simultaneously.