A Facile Method to Prepare Ultrafine Pd Nanoparticles Embedded into N-Doped Porous Carbon Nanosheets as Highly Efficient Electrocatalysts for Oxygen Reduction Reaction

To explore cheap alternatives for platinum electrocatalysts, many strategies have been widely studied. And Pd is regarded as a ideal alternative catalyst due to its high stability and catalytic activity. In this work, we designed a facile method to prepare a highly efficient electrocatalyst in which ultrafine Pd nanoparticles are embedded into N-doped porous carbon nanosheets for oxygen reduction reaction (ORR) in alkaline and acid media. A series of products with different Pd quantities were in situ prepared in the absence of additional reductant and capping agents by varying the addition of PdCl2, while the morphology and the structural features of products through X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD) and transmission electron microscopy (TEM) and BET measurements show that Pd nanoparticles are embedded into N-doped porous carbon nanosheets. Obviously, the sample of Pd-NCs-3 demonstrate the best electrocatalytic activity and remarkable long-term stability among the series, which is superior to that of commercial Pd/C and comparable to that of commercial Pt/C for ORR in alkaline and acid media. The results provides a novel strategy for the rational development of cheap alternatives for platinum electrocatalysts. (C) 2020 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited.