Advanced and In-Situ Electron Microscopy Investigation of Phase Composition and Phase Transformation in Ga-Rh Liquid Metal Catalysts

Supported Catalytic Active Liquid Metal Solutions (SCALMS) have been recently demonstrated to be a highly promising class of heterogeneous catalysts, which show superior activity, robust performance and selectivity in dehydrogenation reactions At typical dehydrogenation temperatures of 500 C, it is conceived that the large surface to volume ratio of the nano-droplets of the liquid metals, supported in the open meso-or macroporous scaffold, provide huge number of catalytically active sites which are intrinsically robust to coke formation and degradation due to the highly dynamic nature of the liquid metal alloy. Such liquid metal nanoalloys are intermetallic compounds of low-melting host elements (e.g., Ga, In) with small amount of catalytically active transition metal elements. These intermetallic compounds typically have complex stable crystal phases in solid state. The structural information, particularly the phase stability of the nanoalloys, is indispensable to render the full picture of their catalytic performance, which is however hardly accessible with catalytic tests and require a combination of in situ surface science, scattering and high-resolution imaging and spectroscopy techniques.