Surface ion isolated platinum-thiocyanate catalysts for hydrogen peroxide production via 2-electron oxygen reduction in acidic media

Abstract

Electrosynthesis of hydrogen peroxide (H2O2) through oxygen reduction reaction (ORR) is an attractive alternative to the traditional anthraquinone process. It offers decentralized and on-site generation of H2O2 with a cost-effective system. Noble metals electrocatalysts through alloying or in a single-atomic structure and a few non-precious metals have been demonstrated with high selectivity but the stability remains challenging. Here, we propose a surface ion isolated platinum-thiocyanate (PtSCNx) catalyst as a promising electrocatalyst for the H2O2 electrosynthesis in acidic media. The SCN– binding remarkably weakens the absorption of crucial *OOH intermediate on the Pt surface, leading to the change of ORR electron transfer pathway. The carbon supported PtSCNx exhibits an onset potential of 0.68 V (versus RHE) and ∼ 90% selectivity. Significantly, the PtSCNx/C shows a continual and stable electrolysis over 130 h, which outperforms the state-of-the-art 2e– ORR catalysts. Moreover, an on-site electrochemical rapid removal of organic pollutant is achieved through an electro-Fenton process.