Hexagonal boron nitride for selective oxidative dehydrogenation of n-hexane to olefins

Oxidative dehydrogenation (ODH) of n-hexane to olefins provides an alternative strategy for efficient utilization of n-hexane. Here, we report that hexagonal boron nitride (h-BN) is selective in ODH of n-hexane, achieving 89.6 % selectivity to olefins at n-hexane conversion of 16.3 % and 550 °C. We found that low temperatures and oxygen rich conditions favor the selective hydrogen abstraction from C-H bond over the cleavage of C-C bond, and the presence of gas phase free radical greatly improves the reaction rate of ODH of n-hexane over h-BN. In addition, an anomalous seagull type of relationship exists between the conversion of n-hexane and reaction temperature, which may be related to the re-distribution of the active sites.