Formation of an Amorphous LaAlBO _x Overlayer on Crystalline LaAlO ₃ Perovskite for Highly Efficient and Stable Propane Oxidative Dehydrogenation

Abstract

ABSTRACT Supported boron oxide catalysts have demonstrated ultra‐high selectivity in the oxidative dehydrogenation of propane (ODHP), but their practical deployment is severely limited by poor thermal stability and rapid deactivation, primarily due to the hydrolysis of active B–O sites forming volatile boric acid. Here, we develop a catalyst comprising a crystalline LaAlO 3 (LAO) perovskite coated with an amorphous LaAlBO x overlayer, achieved through the thermal treatment of physically mixed H 3 BO 3 and LAO. During reaction, the amorphous LaAlBO x overlayer grows in thickness, wherein the concurrent formation of strong M–O–B (M = La, Al) bonds effectively suppress boron volatilization, ensuring long‐term structural stability. The optimized catalyst achieves a propylene yield of 21% and a total olefin selectivity of 97% during continuous operation at 500°C for 100 h, which ranks among the top‐tier performance reported in the literature. Density functional theory (DFT) calculations demonstrate that the formation of M–O–B bonds not only stabilizes boron species from volatilization but also lowers the energy barrier of the rate‐determining‐step in ODHP, thereby leading to remarkable catalytic performance. Importantly, this strategy is found to be extendable to other perovskites (e.g., SmAlO 3 , SrTiO 3 , BaTiO 3 ), underscoring its generality for designing durable boron‑based catalysts.