Uncovering Structural Evolution during the Dealloying Process in Pt-Based Oxygen-Reduction Catalyst

Huijuan Zhang; Minyuan Tan; Longfei Hu; Renjie Gui; Xiaokang Liu; Xue Zhang; Zhiguo Sun; Linlin Cao; Tao Yao

doi:10.1021/acs.jpclett.4c00260

Uncovering Structural Evolution during the Dealloying Process in Pt-Based Oxygen-Reduction Catalyst

J Phys Chem Lett. 2024 Mar 21;15(11):3071-3077. doi: 10.1021/acs.jpclett.4c00260. Epub 2024 Mar 11.

Authors

Huijuan Zhang¹, Minyuan Tan¹, Longfei Hu¹, Renjie Gui², Xiaokang Liu¹, Xue Zhang¹, Zhiguo Sun¹, Linlin Cao¹, Tao Yao^{1

2}

Affiliations

¹ National Synchrotron Radiation Laboratory, School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, 230029, P.R. China.
² Key Laboratory of Precision and Intelligent Chemistry, University of Science and Technology of China, Hefei, 230026, China.

PMID: 38466813
DOI: 10.1021/acs.jpclett.4c00260

Abstract

The comprehensive understanding toward the dealloying process is crucial for designing alloy catalysts employed in the oxygen reduction reaction (ORR). However, the specific leaching procedure and subsequent reconstruction of the dealloyed catalyst still remain unclear. Herein, we employ in situ X-ray absorption fine structure spectroscopy to monitor the dealloying process of a two-dimensional PtTe ordered alloy, known for its enhanced ORR activity. Our findings reveal the unsynchronous evolutions of Pt and Te sites, wherein the Pt component undergoes a structural transformation prior to the complete leaching of Te, leading to the formation of a defect-rich Pt catalyst. This dealloyed catalyst exhibits a significant enhancement in ORR activity, featuring a half-wave potential of 0.90 V versus the reversible hydrogen electrode and a mass activity of 0.62 A mg_Pt^-1, outperforming the performance of commercial Pt/C counterpart. This in-depth understanding of the dealloying mechanism enriches our knowledge for the development of high-performance Pt-based alloy catalysts.