Cuboidal molybdenum sulfur cluster as a platform to construct novel catalyst for propane dehydrogenation

Abstract

Growing demand of short chain olefins such as propylene for plastic production drives the development of high performing catalysts for propane dehydrogenation (PDH). Here, a confinement strategy originating from metal-sulfur clusters was employed to fabricate defective MoPtS_x phase via anchoring by coordinatively unsaturated Al sites present on alumina, followed by reduction under H₂ flow at high temperature. This catalyst with a low Pt content exhibits great ability for C–H activation with high intrinsic activity and facile propylene desorption in PDH reaction. More importantly, this catalyst shows excellent stability during long-term tests with both stable conversion and selectivity. Through combined X-ray absorption spectroscopy, electron microscopy and electron paramagnetic resonance measurements it could be affirmed that the isolated and electron-enriched Pt sites as well as their proximity to adjacent sulfur vacancies is vital for the first and second C–H bond activation, and suppressing of C–C cleavage which otherwise lead to coking.