Al–O–Ti electron bridges in Cr–TiAlOx: dual-functional catalysis for coupled N2O utilization and styrene production

Abstract

The synergistic coupling reaction of N₂O decomposition with ethylbenzene dehydrogenation is a promising strategy for both greenhouse gas mitigation and styrene production. Herein, a Ti-incorporated Cr–Al₂O₃ catalyst was constructed via a P123-assisted evaporation-induced self-assembly method, demonstrating superior catalytic performance in EB dehydrogenation using N₂O as an oxidant, achieving a maximum EB conversion and ST selectivity of approximately 72% and 65%, respectively. Characterization results indicate that Ti incorporation not only enlarges the specific surface area, thereby facilitating the dispersion of Cr oxide, but also influences the distribution of strong acid sites on the catalyst surface, effectively reducing coke deposition. Furthermore, the heightened concentration of surface chemisorbed oxygen derived from the Al–O–Ti interaction emerges as a pivotal factor contributing to the enhanced catalytic activity. In situ DRIFTS identifies a crucial reaction pathway where adsorbed N₂O can react with EB, highlighting that the enhanced N₂O adsorption onto the Cr–6TiAlO_x catalyst is pivotal for its superior catalytic activity.