AbstractThe hydrogen peroxide (H2O2) produced through electrochemical two‐electron oxygen reduction reaction (2e− ORR) is a promising green synthesis method and served as potential strategy to replace the energy‐intensive anthraquinone process. Nevertheless, the design of low‐cost and efficient electrocatalysts for 2e− ORR remains a formidable challenge. In this study, Sn‐BiOCl nanosheets electrocatalysts are prepared for expediting the 2e− ORR, achieving a high H2O2 selectivity of 92.9%, and the H2O2 yield of 10628 mg L−1 h−1 (0.1 mg cm−2) in a flow‐cell device. The in situ ATR‐SEIRAS results reveal that Sn‐BiOCl enhances the adsorption and activation of *OOH compared to BiOCl, resulting in higher activity and selectivity for 2e− ORR. Furthermore, this study investigates the potential for on‐site production and application of H2O2 using Sn‐BiOCl, which displays a 95% degradation removal of dyes (RhB, MB, and MO) within 20 min. This work not only have an insight into the critical roles of Bi and Sn atoms in enhancing the catalytic performance but also provides a thought to design efficient catalysts for production H2O2 via electrochemical 2e− ORR.