Controllable Growing Defects in Cambered Boron Nitride Utilizing a Plane Bending Strategy for Efficient Oxidative Dehydrogenation of Propane
Xinping Zhang, Yanan Huang, Wenhua Zhou, Qinlan Luo, Yangqiang Huang, Xiao Luo, Jiayu Dai, Hao Chen, Jie Fu
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.