Highly efficient and stable ordered mesoporous Ti-Al composite oxide catalyst for oxidative dehydrogenation of ethylbenzene to styrene with CO2

Ordered mesoporous Ti-Al composite oxides (OMTA-x) with variable Al/Ti atomic ratios have been prepared by a facile approach, and were evaluated as catalysts for oxidative dehydrogenation of ethylbenzene to styrene with CO2 (CO2-ODEB). Compared to Al2O3-supported titania catalyst, the resultant catalysts OMTA-x displayed inspiringly improved catalytic performance. For example, catalyst OMTA-2 demonstrated notable activity up to 20 h with maximum styrene yield of 69.4%, even after five times regeneration by calcination. The superior catalytic performance of OMTA-x can be attributed to the highly homogenous dispersion of Ti, the obviously improved surface acidity and redox properties, and the excellent textural and structural properties. The bridging oxygen in the surface Ti4+-O-Al3+. bonds with enhanced reactivity with H were concluded as the critical active sites for dehydrogenation of ethyl benzene, and new understanding for the development of TiO2-based catalysts with superior catalytic activity, stability, and reusability for CO2-ODEB was provided.(C) 2021 Elsevier Ltd. All rights reserved.