Enhanced Electrocatalytic Hydrogen Peroxide Production via a CuWO4/WO3 Heterojunction with High Selectivity and Stability

The electrocatalytic conversion of oxygen to hydrogen peroxide offers a promising pathway for sustainable energy production. However, the development of catalysts that are highly active, stable, and cost-effective for hydrogen peroxide synthesis remains a significant challenge. In this study, a novel polyacid-based metal-organic coordination compound (Cu-PW) was synthesized using a hydrothermal approach. Cu-PW served as a precursor to construct a composite electrocatalyst featuring a heterointerface between CuWO₄ and WO₃ (CuWO₄/WO₃) through pyrolysis. The CuWO₄/WO₃ heterojunction exhibits an impressive H₂O₂ selectivity of 91.84% at 0.5 V, marking a 19.65% improvement compared to the pristine Cu-PW. Furthermore, the CuWO₄/WO₃ catalyst demonstrates exceptional stability, maintaining continuous operation for 29 h. At 0.1 V, it delivers a hydrogen peroxide yield of 1537.8 mmol g^-1 h^-1, with a Faraday efficiency (FE) of 85%. Additionally, this catalyst effectively degrades methyl blue, achieving a 95% removal from an aqueous system within 30 min. Theoretical analysis further corroborates the high electroactivity of CuWO₄/WO₃ heterojunction structure. The Cu-O-W bridge formed during the reaction facilitates interfacial electron transport and enhances the role of the W-O bond in proton adsorption and transfer kinetics. This strong interfacial coupling in CuWO₄/WO₃ promotes electron transfer and the formation of *OOH intermediates, thereby favoring hydrogen peroxide generation. Hence, the as-prepared CuWO₄/WO₃ demonstrates great potential as an efficient electrocatalyst for the green synthesis of hydrogen peroxide, exhibiting high efficiency as a two-electron oxygen reduction reaction catalyst. This work offers a new approach for fabricating CuWO₄/WO₃ electrocatalyst with high electroactivity and selectivity, paving the way for cost-effective and sustainable hydrogen peroxide production, significantly reducing reliance on the conventional anthraquinone process.