Size-Controlled Intermetallic PtZn Nanoparticles on N-Doped Carbon Support for Enhanced Electrocatalytic Oxygen Reduction
Xiao Han, Qiuxiang Wang, Zhiping Zheng, Zi‐Ang Nan, Xibo Zhang, Zhijia Song, Min Ma, Jun Zheng, Qin Kuang, Lan‐Sun Zheng
Abstract
Recently, Pt-based intermetallic nanoparticles (iNPs) have been intensely studied to improve the electrocatalytic activity/stability and Pt atomic utilization, but how to control the size of Pt-based iNPs is still a great challenge to date. Here, uniform PtZn intermetallic nanoparticles with a well-defined size supported on a conductive N-doped carbon (NC) were facilely synthesized by direct pyrolysis of sandwich-like zeolithic imidazolate framework (ZIF)-8@GO composites modified with tetra(4-carboxyphenyl)porphine (TCPP) anchored Pt sites. Innovatively, TCPP was used as a bifunctional coordination agent to coordinate with both Pt ions and ZIF-8. The size of intermetallic PtZn nanoparticles could be well controlled from ca. 2 to 5 and 7 nm by increasing calcination temperature. Compared to the benchmark Pt/C (E1/2 of 0.875 V), the 5 nm PtZn/NC composites (E1/2 of 0.911 V) exhibited a significantly improved electrocatalytic performance for oxygen reduction reaction. The size uniformity control strategy presented in this work opens up a new way to boost the activity and stability of Pt-based catalysts in fuel cells.