Hexagonal boron nitride (h-BN) has lately received great attention in the oxidative dehydrogenation (ODH) reaction of propane to propylene for its extraordinary olefin selectivity in contrast to metal oxides. However, high crystallinity of commercial h-BN and elusive cognition of active sites hindered the enhancement of utilization efficiency. Herein, four kinds of plasmas (N2 , O2 , H2 , Ar) were accordingly employed to regulate the local chemical environment of h-BN. N2 -treated BN exhibited a remarkable activity, i.e., 26.0 % propane conversion with 89.4 % selectivity toward olefins at 520 °C. Spectroscopy demonstrated that "three-boron center" N-defects in the catalyst played a pivotal role in facilitating the conversion of propane. While the sintering effect of the "BOx " species in O2 -treated BN, led to the suppressed catalytic performance (12.4 % conversion at 520 °C).
Keywords: hexagonal boron nitride; nitrogen-defects; oxidative dehydrogenation; plasma; sintering.
© 2021 Wiley-VCH GmbH.