Exclusive Strain Effect Boosts Overall Water Splitting in PdCu/Ir Core/Shell Nanocrystals. Issue 15 (3rd March 2021)

• Record Type: Journal Article
• Authors: Li, Menggang; Zhao, Zhonglong; Xia, Zhonghong; Luo, Mingchuan; Zhang, Qinghua; Qin, Yingnan; Tao, Lu; Yin, Kun; Chao, Yuguang; Gu, Lin; Yang, Weiwei; Yu, Yongsheng; Lu, Gang; Guo, Shaojun
• Is Part Of: Angewandte Chemie international edition. Volume 60:Issue 15(2021)
• Page Start: 8243
• Page End: 8250
• Publication Date: 2021-03-03
• Subjects: core/shell structure -- overall water splitting -- oxygen evolution reaction (OER) -- nanocrystals -- strain effect; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202016199
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Core/shell nanocatalysts are a class of promising materials, which achieve the enhanced catalytic activities through the synergy between ligand effect and strain effect. However, it has been challenging to disentangle the contributions from the two effects, which hinders the rational design of superior core/shell nanocatalysts. Herein, we report precise synthesis of PdCu/Ir core/shell nanocrystals, which can significantly boost oxygen evolution reaction (OER) via the exclusive strain effect. The heteroepitaxial coating of four Ir atomic layers onto PdCu nanoparticle gives a relatively thick Ir shell eliminating the ligand effect, but creates a compressive strain of ca. 3.60%. The strained PdCu/Ir catalysts can deliver a low OER overpotential and a high mass activity. Density functional theory (DFT) calculations reveal that the compressive strain in Ir shell downshifts the d‐band center and weakens the binding of the intermediates, causing the enhanced OER activity. The compressive strain also boosts hydrogen evolution reaction (HER) activity and the strained nanocrystals can be served as excellent catalysts for both anode and cathode in overall water‐splitting electrocatalysis. Abstract : By precisely controlling the thickness of the shell layer, an exclusive strain effect and the complete elimination of the ligand effect can be achieved on the PdCu/Ir core/shell nanocrystals to optimize the d‐band center and boost electrocatalytic overall water splitting performance.