Regulating the stability of boron oxide active species under high-temperature and humid conditions by engineering pore walls

The loss of active centers is the key factor that limits the lifespan of catalysts. Supported boron oxide (B2O3/SiO2) catalysts, despite their high selectivity and productivity in oxidative dehydrogenation of propane (ODHP), suffer from rapid leaching of boron oxide species under harsh reaction conditions. In this study, we employed atomic layer deposition (ALD) to create stable and porous ALD-Al2O3 walls on 17B2O3/SiO2 catalysts. Through catalytic ODHP conducted under high-temperature and humid conditions, the mean leaching rate of boron oxide decreased from 0.57 to 0.10 wt % h−1, demonstrating an approximately 5.7-fold reduction. The porous ALD-Al2O3 walls, exhibiting sufficient thickness (>10 nm) and abundant micropores (∼1.7 nm), effectively confined the boron oxide. The presence of numerous hydroxyl groups within these narrow channels significantly strengthens the interaction between the boron oxide and the ALD-Al2O3 walls. This work introduces a novel approach to confine volatile catalytic active components under challenging operational circumstances.