Synthesis of sphere-shaped TiO2/Al2O3 catalyst support for propane dehydrogenation by Pechini-type sol-gel process and its stability during reaction-regeneration cycles

Commercial Pt-based catalysts for the propane dehydrogenation (PDH) process suffer from coking and structural stability problems and require frequent regeneration. Using mixed oxides as supports to develop high-performance catalysts has been proven to be an effective strategy. However, the stability of structure and performance during reaction-regeneration cycles has rarely been investigated. The Pechini method was used to synthesize TiO 2 /Al 2 O 3 composite oxides as the catalyst support for the PDH reaction. The prepared supports and catalysts were characterized by HAADF-STEM, XPS, NH 3 -TPD, C 3 H 6 -DRIFTS, CO chemisorption, etc. Under optimized preparation conditions, an appropriate TiO 2 /Al 2 O 3 mixed oxide (0.04Ti2) was obtained by adjusting the loading amount and coating times. This material enhanced the dispersion of supported Pt and improved its catalytic performance. The adverse effect of introducing an excessive amount of TiO 2 could be ruled out, and the mechanical strength of the original Al 2 O 3 balls was maintained. The stability of the catalytic performance of 0.3Pt/0.04Ti2 during reaction-oxychlorination regeneration cycles was also verified, and the final stable catalytic performance (98% propylene selectivity at ∼20% propane conversion) was superior to that of Pt supported on Al 2 O 3 balls.