Face-Centered Cubic Ruthenium Nanocrystals with Promising Thermal Stability and Electrocatalytic Performance
Qing Yao, Shengyao Lv, Zhiyong Yu, Yu‐Chung Chang, Chih‐Wen Pao, Zhiwei Hu, Li‐Ming Yang, Xiaoqing Huang, Qi Shao, Jianmei Lu
Abstract
The rational design of Ru nanocrystals with a metastable face-centered cubic (fcc) structure is highly important for catalytic applications and yet remains a challenge. Herein, we have successfully prepared a unique core–shell structure consisting of structurally disordered Cu 2 O (core) and fcc Ru (shell) (Cu 2 O@Ru fcc ) via a facile chemical method. The experimental investigations show that Cu 2 O, which is formed in the initial stage and becomes disordered in the subsequent structural evolution, plays a pivotal role in Ru stacking into the fcc structure. Benefiting from the distinct structural advantage, the fcc Ru structure of Cu 2 O@Ru fcc shows good thermal stability with preserving the phase transition temperature up to 500 °C according to the in situ measurement, which is much better than those of Ru fcc, Cu@Ru fcc, and most reported materials. The X-ray absorption spectroscopy (XAS) analysis identifies the strong interaction of disordered Cu 2 O and fcc Ru. Further theoretical calculation reveals that the phase stability of Cu 2 O@Ru fcc mainly originates from the strong interfacial interaction of the core and shell. When used as an electrocatalyst, the Cu 2 O@Ru fcc exhibits superior performance over the Ru fcc, Ru hcp, and commercial Pt/C in both the alkaline hydrogen evolution reaction and hydrogen oxidation reaction. This work highlights a potential strategy for designing fcc Ru nanocrystals with favorable properties and promising applications.