Controllable Growing Defects in Cambered Boron Nitride Utilizing a Plane Bending Strategy for Efficient Oxidative Dehydrogenation of Propane

Abstract

Hexagonal boron nitride (h-BN) can inhibit olefin overoxidation during the oxidative dehydrogenation of propane (ODHP) but shows intrinsically low catalytic activity because of the limited B–O active sites formed at B edges and N defects. Herein, we report a strategy based on plane bending to synthesize cambered h-BN by the encapsulation–elution of metal (Cu, Fe, Co, and Ni) nanoparticles. Combining the results of NEXAFS, XPS, and DFT calculations, it was shown that large numbers of defects, especially the “seven-boron center” N defects, were formed by plane bending of BN, resulting in a large number of B–O active species for enhanced ODHP. The creation of these defects in h-BN resulted in 31.7% and 37.0% olefin yields under a WHSV of 7200 h^–1 using Cu (500 °C) and Fe (520 °C) nanoparticles as templates, respectively. In situ DRIFTS coupled with DFT calculations showed that the high activity of these defect-engineered h-BNs resulted from highly efficient C–H activation and cleavage and the kinetics-favorable formation of C═C on abundant B–O active sites. The plane bending effect provides a way for in situ growth of defects on h-BN to enhance the ODHP, which promotes its industrial catalysis applications.