Synthesis and properties of core-shell metal-ceramic microstructures and their application as heterogeneous catalysts

A facile synthesis of core-shell metal-ceramic microcomposites with unique structural and chemical properties and their superior performance as heterogeneous catalysts are reported. These core-shell microstructures were prepared by hydrothermal surface oxidation of Al particles in water with or without the presence of heterometal species followed by calcination. The crystalline porous MgAl₂O₄ spinel, which has complex morphological features, allowed the superior dispersion and stability of Rh clusters, and the core-shell microarchitecture provided facilitated heat and mass transport concomitantly, which enabled a significant enhancement in the glycerol conversion turnover rate to hydrogen compared to the conventional Rh/MgAl₂O₄ catalyst. This simple and scalable heterogeneous catalyst design approach offers practical applicability for catalytic reactions that require extensive heat and mass flux and rapid process response, such as for micro-fuel-processing in fuel cells.