Sinter-resistant metal nanoparticle catalysts achieved by immobilization within zeolite crystals via seed-directed growth

Supported metal nanoparticle catalysts are widely used in industry but suffer from deactivation resulting from metal sintering and coke deposition at high reaction temperatures. Here, we show an efficient and general strategy for the preparation of supported metal nanoparticle catalysts with very high resistance to sintering by fixing the metal nanoparticles (platinum, palladium, rhodium and silver) with diameters in the range of industrial catalysts (0.8-3.6 nm) within zeolite crystals (metal@zeolite) by means of a controllable seed-directed growth technique. The resulting materials are sinter resistant at 600-700 degrees C, and the uniform zeolite micropores allow for the diffusion of reactants enabling contact with the metal nanoparticles. The metal@zeolite catalysts exhibit long reaction lifetimes, outperforming conventional supported metal catalysts and commercial catalysts consisting of metal nanoparticles on the surfaces of solid supports during the catalytic conversion of C-1 molecules, including the water-gas shift reaction, CO oxidation, oxidative reforming of methane and CO2 hydrogenation.