Unveiling the True Micro-Structure in PdRu Immiscible Alloys and Its Application in Alkaline Hydrogen Evolution Reaction

Abstract The structure information in a disordered atomic system could not be acquired from the daily X-ray diffractometers, but has to resort to the synchrotron sources. The pair distribution function from the synchrotron X-ray and neutron scattering reflects the local bond information regardless of the crystallinity, but the limited access to these high-energy light resources prevents them from wide use. Herein we developed a microstructure analysis framework to study the immiscible binary alloys, through the integration of local elemental segregation analysis, electron-based pair distribution function, the corresponding wavelet coherence spectrum, and ab-initio level simulation. All the information could be obtained from an in-house transmission electron microscope equipped with an energy dispersive spectroscope. A series of nanoparticles based on immiscible Pd-Ru alloys were chosen as the model catalysts for hydrogen evolution reaction and the structure-performance relationship was established based on the electrochemical tests and the structure information from the analysis toolkit we developed.