B-Site Engineering in Ruddlesden-Popper Perovskites (A<sub>2</sub>BO<sub>4</sub>) for H<sub>2</sub>O<sub>2</sub> Production with 4.85% of Solar-to-Chemical Efficiency.

Cho, Jaewon; Choi, Jun-Yong; Jeong, Eunjae; Yu, Je Min; Kim, Youngchul; Lee, Hyunjoo; Lee, Sang-Goo; Lee, Geunsik et al. · Nano Lett · 2026

basic_science · Level V

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Abstract

The electrochemical synthesis of hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) via the oxygen reduction reaction (ORR) offers a promising alternative to the anthraquinone process, addressing environmental concerns without requiring expensive hydrogen. However, developing catalysts that selectively promote the two-electron ORR pathway while maintaining stability remains challenging. Here, we report Ruddlesden-Popper (RP) perovskite oxides as efficient catalysts for selective H<sub>2</sub>O<sub>2</sub> production. Among the tested LaSrBO<sub>4</sub> compositions (B = Ni, Co, Fe, Mn), LaSrNiO<sub>4</sub> (LSN) showed the best two-electron ORR selectivity (∼87%) and activity. Integrated into a photovoltaic-electrochemical system, LSN achieved a solar-to-chemical conversion efficiency of 4.85%, producing a H<sub>2</sub>O<sub>2</sub> production rate of 149.2 μmol cm<sup>-2</sup> h<sup>-1</sup> with good stability over 50 h. Density functional theory calculations attributed this performance to favorable H<sub>2</sub>O<sub>2</sub> formation and desorption kinetics at the Ni B-site. Overall, RP perovskites offer earth-abundant, efficient, and sustainable catalysts for electrochemical H<sub>2</sub>O<sub>2</sub> generation, providing an alternative to carbon- or noble-metal-based systems.