In situ growth of phosphorus-doped boron nitride on commercial alumina as a robust catalyst for direct dehydrogenation of ethylbenzene

Abstract

Direct dehydrogenation of ethylbenzene to styrene catalyzed by metal-free materials is one of the most challenging topics in the chemical industry currently. Here, PBN@Al₂O₃(N) synthesized by in situ growth of phosphorus-doped boron nitride on commercial alumina is reported as a highly stable catalyst for at least 300 h with a stable ethylbenzene conversion of 93.51% and a styrene selectivity of over 95%, respectively. Control experiments and characterization indicated that the activity could be attributed to the combination of active sites on thin PBN layers and the boron-modified alumina surface, which enhanced the strength and amount of moderate acidic and basic sites. Besides, the even coverage of PBN on the porous alumina sphere ensured the excellent mass transfer of the reactant and product, leading to the obviously improved stability. The accessibility of commercial alumina and the facile synthesis technique made the catalyst an outstanding prospect for large-scale industrial application.