In this study, a facile approach has been successfully applied to synthesize a hierarchical three-dimensional architecture of ultrasmall hematite nanoparticles homogeneously encapsulated in MoS₂/nitrogen-doped graphene nanosheets, as a novel non-Pt cathodic catalyst for oxygen reduction reaction in fuel cell applications. The intrinsic topological characteristics along with unique physicochemical properties allowed this catalyst to facilitate oxygen adsorption and sped up the reduction kinetics through fast heterogeneous decomposition of oxygen to final products. As a result, the catalyst exhibited outstanding catalytic performance with a high electron-transfer number of 3.91–3.96, which was comparable to that of the Pt/C product. Furthermore, its working stability with a retention of 96.1% after 30 000 s and excellent alcohol tolerance were found to be significantly better than those for the Pt/C product. This hybrid can be considered as a highly potential non-Pt catalyst for practical oxygen reduction reaction application in requirement of low cost, facile production, high catalytic behavior, and excellent stability.

中文翻译：

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超小型Fe ₂ O ₃包覆的MoS ₂ / N-石墨烯的分层异质结构作为氧还原反应的有效催化剂

在这项研究中，一种简便的方法已成功地应用于合成均一封装在MoS _2中的超小型赤铁矿纳米颗粒的分级三维结构/氮掺杂的石墨烯纳米片，作为一种新型的非Pt阴极催化剂，用于燃料电池应用中的氧还原反应。固有的拓扑特征以及独特的理化性质使该催化剂能够促进氧的吸附，并通过氧快速异质分解为最终产物而加快了还原动力学。结果，该催化剂表现出出色的催化性能，其电子转移数为3.91–3.96，可与Pt / C产物相媲美。此外，发现其在30 000 s后保持96.1％的工作稳定性和出色的耐醇性明显优于Pt / C产品。