Hydrogen peroxide is considered one of the most important commodity chemicals worldwide but its main production method, the anthraquinone process, poses serious logistical, environmental and safety challenges. Electrocatalytic synthesis through the reduction of molecular oxygen is a promising H₂O₂ production route. However, the reduction of molecular oxygen is kinetically hindered and stable electrocatalysts with a high activity and selectivity towards the 2-electron transfer reaction are needed. In this work, we evaluated the influence of chloride on catalysts with low palladium loadings on the ORR selectivity towards H₂O₂. We report the factors and dynamics that influence H₂O₂ production and highlight synthesis strategies to obtain close to 100% selectivity. By probing the electrode surface after various degradation cycles, we evaluate the role of adsorbing species and the catalysts oxidation states on the hydrogen peroxide selectivity. We systematically modified the catalyst synthesis using different Pd-precursors that were reduced and supported on high surface area graphene nanoribbons. Identical location transmission electron microscopy was used to probe catalyst dynamics during reaction and the activities and selectivities were measured by a rotating ring disk electrode. We probe the potential boundary conditions that lead to catalyst degradation during accelerated stress tests and potentiostatic polarisation and demonstrate how the catalytically active surface can be revived after degradation. The obtained insights can be used as guideline for the development of active, selective and stable catalysts with low noble metal loadings.

过氧化氢被认为是世界上最重要的商品化学品之一，但其主要生产方法蒽醌法对后勤，环境和安全提出了严峻挑战。通过还原分子氧的电催化合成是一种有前途的H ₂ O ₂生产途径。然而，分子氧的还原在动力学上受阻，并且需要具有高活性和对2-电子转移反应的选择性的稳定的电催化剂。在这项工作中，我们评估了氯化物对低钯催化剂对ORR对H ₂ O ₂选择性的影响。我们报告了影响H ₂ O ₂的因素和动力学生产并强调合成策略以获得接近100％的选择性。通过探测各种降解循环后的电极表面，我们评估了吸附物种和催化剂氧化态对过氧化氢选择性的作用。我们使用不同的Pd前体系统地修饰了催化剂的合成，这些Pd前体被还原并负载在高表面积石墨烯纳米带上。相同的位置透射电子显微镜用于探测反应过程中催化剂的动力学，并通过旋转环盘电极测量活性和选择性。我们探究了在加速应力测试和恒电位极化过程中导致催化剂降解的潜在边界条件，并演示了降解后如何恢复催化活性表面。