Continuous Flow Liquid-Phase Semihydrogenation of Phenylacetylene over Pd Nanoparticles Supported on UiO-66(Hf) Metal-Organic Framework

Abstract

Catalysis under continuous flow operation is industrially more relevant compared to reactions carried out in batch reactors. But catalysis with metal-organic frameworks (MOFs) is largely restricted to batch reactions, especially in case of semi hydrogenation reactions. We anchored Pd nanoparticles (NPs) on robust UiO-66(Hf) MOF to develop effective catalyst for semi hydrogenation of phenylacetylene into styrene. We investigated catalytic performance of Pd/UiO-66(Hf) in a continuous-flow liquid-phase semi-hydrogenation of phenylacetylene (PA). In this study, Pd/UiO-66(Hf) catalyst exhibited good catalytic performance with a rare combination of high PA conversion (99.0 %) and high styrene selectivity (90.0 %). Additionally, Pd/UiO-66(Hf) demonstrated lower deactivation rate in contrast to many reported materials to date. The higher stability of metal NPs over UiO-66(Hf) aroused from the strong metal-support interaction (between Brønsted acidic μ3-OH of MOF and Pd). The Pd/UiO-66(Hf) retained its catalytic activity even after four recycles.