Investigation into the stability of monometallic metal oxide electrocatalysts for hydrogen peroxide synthesis through the oxygen reduction reaction

Abstract

The electrochemical synthesis of hydrogen peroxide (H₂O₂) via the two-electron oxygen reduction reaction (2e⁻ ORR) constitutes an environmentally benign and sustainable alternative to conventional anthraquinone oxidation (AO) technology. To enable industrial implementation of this methodology, the development of cost-effective, durable, and highly efficient electrocatalysts represents an imperative requirement. In contrast to the prohibitive costs associated with noble metals, transition metal oxides (TMOs) demonstrate substantial advantages in terms of natural abundance, economic viability, catalytic activity, and selectivity, thereby establishing themselves as competitive substitutes for traditional noble metal-based oxygen electrocatalysts. Nevertheless, the structural integrity and catalytic performance of TMOs are prone to degradation under the inherent rigorous operational conditions of electrochemical H₂O₂ production. This review systematically investigates the factors governing the stability of TMOs through thermodynamic and kinetic analyses. By elucidating structure–performance correlations, it consolidates stabilization strategies for TMOs, substantiated by representative case studies. Furthermore, the intricate relationships between catalyst stability, synthetic protocols, and reactor configurations are examined. The discussion culminates in delineating prospective opportunities and challenges for future research directions. This comprehensive analysis aims to establish a foundational framework for designing high-performance TMO catalysts, ultimately advancing the industrial-scale implementation of TMO-mediated 2e⁻ ORR systems.