p-Block Metal-Based Catalysts: Hidden Gems for Hydrogen Peroxide Electrosynthesis

Electrosynthesis of hydrogen peroxide (H₂O₂) via the oxygen reduction reaction (ORR) offers a sustainable alternative for the traditional anthraquinone method. p-block metals exhibit unique electronic structures and tunable surface properties, showing great potential in 2e^- ORR. However, a systematic review focusing on recent progress in p-block metal-based electrocatalysts for H₂O₂ synthesis is lacking. To fill the gap, this work first shows a marked increase in p-block metal research over the past decade by bibliometric analysis of over 300 publications. Research on 2e^- ORR has surged since 2019, while research on 2e^‒ water oxidation reaction (WOR) has declined. Strategies for the synthesis and optimization of various p-block metal-based catalysts are discussed in detail. Based on a synthesis of DFT calculations in the literature, the reaction mechanisms of p-block metal catalysis proceeding are summarized via a 2e^- pathway. Finally, considering the merits and limitations of different metals, this review outlines the primary challenges and future directions in this area, emphasizing the importance of improving catalyst stability, deepening mechanistic understanding, and developing cost-effective synthesis methods. It also offers novel perspectives on the engineering of p-block metal-based catalysts and promotes the development of sustainable H₂O₂ electrosynthesis technologies.