Sulfur poisoned PtNi/C catalysts toward two-electron oxygen reduction reaction for acidic electrosynthesis of hydrogen peroxide

Selective electrocatalysis of two-electron oxygen reduction reaction (2e – ORR) has been recognized as a sustainable and on-site process for hydrogen peroxide (H 2 O 2 ) production. Great progress has been achieved for 2e – ORR in alkaline media. However, it is challenged by insufficient activity and selectivity of the catalysts in acidic electrolytes. Herein, we report sulfur-poisoned PtNi/C catalysts (PtNiS x /C) that could regulate ORR from the 4e – to 2e – pathway. The identified PtNiS 0.6 /C offers high activity in terms of onset potential of ∼0.69 V (vs. RHE) and ∼80 % selectivity. The mass activity is also comparable and outperforms representative Pt-based precious and transition-metal-based catalysts. In addition, it is interestingly found that the Faradaic efficiency further increased to 95 % during the long-term electrolysis test due to Ni atom surface migration. The electrochemical production of the H 2 O 2 system was applied to the electro-Fenton process, which has realized the effective degradation of organic pollutants. This work offers a strategy by sulfur poisoning PtNi/C catalyst to realize Pt-based 2e – ORR active catalysts to electrolysis of H 2 O 2 in acidic media.