Anti-poisoning core-shell metal/ZIF-8 catalyst for selective alkene hydrogenation

We report a synthesis strategy for preparing a core-shell zeolitic imidazolate framework-8 (ZIF-8)-supported metal (gold or palladium) composite with catalytic selectivity and anti-poisoning properties. The catalytic performance of this ZIF-8/metal/ZIF-8 composite was investigated in catalytic alkene hydrogenation. The prepared ZIF-8/Pd/ZIF-8 composites exhibited high catalytic selectivity for 1-hexene over cis-cyclooctene and effectively protected the Pd particles from poisoning by thiophene during hydrogenation. The spent catalyst was almost fully regenerated after removing the adsorbed sulfur impurities. The reported core-shell catalyst design could be applicable to reactions in which the reactants to be processed contain components that could potentially poison the active sites.