Highly efficient propyne semihydrogenation over tin-modified Co-based intermetallic catalyst

Abstract

Designing and fabricating uniformly dispersed non-precious metal active sites with tuned geometric configurations and local coordination environments for the selective conversion of functional groups to desired products is of great importance but remains challenging in industrial catalytic processes. In this work, we propose a straightforward method for synthesizing the Co₃Sn₂ intermetallic catalyst through the structural conversion of layered double hydroxide precursors, thereby constructing suitable Sn-modified Co active sites and an optimized catalytic environment for propyne semihydrogenation. Characterizations using x-ray diffraction, high-resolution transmission electron microscopy, and x-ray absorption spectroscopy characterizations are combined to identify the formation of P6₃/mmc Co₃Sn₂ intermetallic phase. Catalytic performance tests show that the Co₃Sn₂ catalyst achieves 95.0% propylene selectivity with nearly complete propyne conversion. Temperature-programmed surface reaction and desorption measurements combined with theoretical calculations demonstrate that the good selectivity is driven by the facile desorption of propylene from Sn-modified Co sites rather than its further hydrogenation.