Edge-hydroxylated Boron Nitride for Oxidative Dehydrogenation of Propane to Propylene

Oxidative dehydrogenation of propane to olefins is a promising alternative route to industrialized direct dehydrogenation, but encounters the difficulty in selectivity control for olefins because of the overoxidation reactions that produce a substantial amount of undesired CO2. Here we report edge-hydroxylated boron nitride, a metal-free catalyst, that efficiently catalyzed dehydrogenation of propane to propylene with superior selectivity (80.2 %) but with only negligible CO2 formation (0.5%) at a given propane conversion of 20.6 %. Remarkable stability was evidenced by the operation of a 300 h test with steady conversion and product selectivity. The active BNO center dot site, generated dynamically through hydrogen abstraction of B-OH groups by molecular oxygen, triggered propane dehydrogenation by selectively breaking the C-H bond but simultaneously shut off the pathway of propylene overoxidation towards CO2.