Efficient Alkyne Semihydrogenation Catalysis Enabled by Synergistic Chemical and Thermal Modifications of a PdIn MOF.

Recently, there has been a growing interest in using MOF templating to synthesize heterogeneous catalysts based on metal nanoparticles on carbonaceous supports. Unlike the common approach of direct pyrolysis of at high temperatures, this work proposes a reductive chemical treatment under mild conditions before pyrolysis (resulting in ). The resulting material () underwent comprehensive characterization via state-of-the-art aberration-corrected electron microscopy, N physisorption, X-ray absorption spectroscopy, Raman, X-ray photoelectron spectroscopy, and X-ray diffraction. These analyses have proven the existence of PdIn bimetallic nanoparticles supported on N-doped carbon. In situ DRIFT spectroscopy reveals the advantageous role of indium (In) in regulating Pd activity in alkyne semihydrogenation. Notably, incorporating a soft nucleation step before pyrolysis enhances surface area, porosity, and nitrogen content compared to direct MOF pyrolysis. The optimized material exhibits outstanding catalytic performance with 96% phenylacetylene conversion and 96% selectivity to phenylethylene in the fifth cycle under mild conditions (5 mmol phenylacetylene, 7 mg cat, 5 mL EtOH, R.T., 1 H bar).