Fine-tuning of Pd-Rh core-shell catalysts by interstitial hydrogen doping for enhanced methanol oxidation

• Published in: Nano research Vol. 15; no. 2; pp. 1288 - 1294
• Main Authors: Guo, Xiaoyun, Hu, Zheng, Lv, Jianxin, Li, Hui, Zhang, Qinghua, Gu, Lin, Zhou, Wei, Zhang, Jiangwei, Hu, Shi
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01-02-2022; Springer Nature B.V
• Subjects: Alloying; Atomic/Molecular Structure and Spectra; Bimetals; Biomedicine; Biotechnology; Catalysts; Catalytic activity; Charge transfer; Chemical synthesis; Chemistry and Materials Science; Condensed Matter Physics; Distribution functions; Doping; Electrochemistry; Electron diffraction; Electronic structure; Ethanol; Function analysis; Hydrogen; Hydrogen atoms; Laboratories; Materials Science; Methanol; Microprocessors; Morphology; Nanoparticles; Nanotechnology; Optimization; Oxidation; Palladium; Performance enhancement; Physics; Potassium; Research Article; Rhodium; Science; Spectroscopy; hydride; electrocatalysis; interstitial alloy; core-shell structure; methanol oxidation reaction
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-021-3652-0

Metal catalysts play an important role in the catalytic electrochemical processes and optimization of their performance is usually achieved through alloying with other metal atoms. Doping with interstitial hydrogen atoms is a special but effective way to regulate the electronic structure of host catalysts. Herein we demonstrate the intermixing of Pd and Rh atoms during the hydrogen-doping process of Pd@Rh core-shell nanocubes, forming an alloyed surface in Pd@Rh-H. The catalysts show enhanced performance in electrocatalytic methanol oxidation, as compared to commercial Pt/C and are even better than PdH@Rh core-shell nanocubes. The small structural differences between the two hydride catalysts are revealed by X-ray electron spectroscopy and pair distribution function analysis of electron diffraction. The theoretical calculation results show that Rh in Pd@Rh-H contains more negative charges than Rh in PdH@Rh, indicating more effective charge transfer in Pd@Rh-H. The d-band center (
ε
d
) of the Rh site in Pd@Rh-H shifts up, and the synergy between Rh and Pd optimizes the binding energy of CO and OH, inducing preferential catalytic activity. Our work provides guidance for the synthesis of high-performance catalysts by doping with interstitial atoms, which may provide a new strategy to fine-tune the electronic structure of other bimetallic nanoparticles.