Enhanced catalytic performance of Pd/HMIL-121 catalysts with hierarchical porosity for selective hydrogenation of phenylacetylene: mechanistic insights and comparative analysis

Metal–organic frameworks with Al metal nodes, being stable and cost-effective materials, are well suited for use as catalyst supports. In this study, a hierarchical Pd/HMIL-121 catalyst with adjustable pore sizes was synthesized through heat treatment using MIL-121 as the support. The study reveals that as thermal treatment intensity escalates, the pore volume and specific surface area of HMIL-121 initially rise and then decrease. Concurrently, as the pore volume and specific surface area increase, the styrene selectivity improves, and the rate of phenylacetylene conversion accelerates. This is attributed to the larger pore volume significantly enhancing the internal diffusion of phenylacetylene and styrene.