Face-Centered Cubic Ruthenium Nanocrystals with Promising Thermal Stability and Electrocatalytic Performance

The rational design of Ru nanocrystals with a metastableface-centeredcubic (fcc) structure is highly important for catalytic applicationsand yet remains a challenge. Herein, we have successfully prepareda unique core-shell structure consisting of structurally disorderedCu(2)O (core) and fcc Ru (shell) (Cu2O@Ru-fcc) via a facile chemical method. The experimental investigationsshow that Cu2O, which is formed in the initial stage andbecomes disordered in the subsequent structural evolution, plays apivotal role in Ru stacking into the fcc structure. Benefiting fromthe distinct structural advantage, the fcc Ru structure of Cu2O@Ru-fcc shows good thermal stability with preservingthe phase transition temperature up to 500 & DEG;C according to the in situ measurement, which is much better than those ofRu(fcc), Cu@Ru-fcc, and most reported materials.The X-ray absorption spectroscopy (XAS) analysis identifies the stronginteraction of disordered Cu2O and fcc Ru. Further theoreticalcalculation reveals that the phase stability of Cu2O@Ru-fcc mainly originates from the strong interfacial interactionof the core and shell. When used as an electrocatalyst, the Cu2O@Ru-fcc exhibits superior performance over theRu(fcc), Ru-hcp, and commercial Pt/C in both thealkaline hydrogen evolution reaction and hydrogen oxidation reaction.This work highlights a potential strategy for designing fcc Ru nanocrystalswith favorable properties and promising applications.

Automated summary

A unique core-shell structure of structurally disordered Cu(2)O (core) and fcc Ru (shell) (Cu2O@Ru-fcc) was successfully prepared via a facile chemical method. The fcc Ru structure of Cu2O@Ru-fcc showed good thermal stability and superior electrocatalytic performance in hydrogen evolution and hydrogen oxidation reactions, highlighting the potential of designing fcc Ru nanocrystals with favorable properties and promising applications.