Increased hydroxyl concentration by tungsten oxide modified h-BN promoted catalytic performance in partial oxidation of methane

摘要

Hexagonal boron nitride (h-BN) as a layered inorganic nonmetallic material has been widely used. Hydrogen peroxide (H2O2) modification can trigger exfoliation and afford abundant B-OH active sites at edge of h-BN, which can enhance methane activation ability. Introducing tungsten oxide (WO3) to h-BN produces a similar effect, because doping WO3 into h-BN resulted in electron transfer to N, inducing fracture of B-N bond, resulting in N vacancy (triboron center), exposing more B sites and promoting the generation of B-OH. Significantly, the introduction of WO3 on the modified h-BN dramatically increased the concentration of B-OH compared with the unmodified h-BN, because H2O2 modification weakened B-N bond. By means of XRD, TEM, XPS,EPR, FT-IR, it is proved that the high concentration of B-OH active sites contributed to activating C-H bond, thus methane conversion and CO and H-2 selectivity were significantly improved. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.