The propane dehydrogenation reaction is thermodynamically unfavorable, tnecessitating kinetic control through optimized process conditions. Single?factor experiments and multi?factor Response Surface Methodology (RSM) were employed to analyze and optimize propane dehydrogenation conditions over a PtSnK/Al?O? catalyst, followed by experimental verification. First, single?factor experiments determined the range of values for the factors to be studied in the response surface methodology. Then, a Box?Behnken design with three factors (reaction temperature, space velocity, and hydrogen?hydrocarbon ratio) was used to optimize the reaction conditions of propane dehydrogenation by multifactor response surface methodology with propylene selectivity as the response value, and finally, the optimized process conditions were experimentally verified. Results indicated that the optimal reaction temperature, VHSV, and H?/C?H? molar ratio were 605 ℃, 2 200 h?1, and 0.6, respectively. The theoretical propylene selectivity prediction under these conditions was 93.01%. The order of influence weight from largest to smallest was reaction temperature > H?/C?H? molar ratio > VHSV. Experimental verification yielded a propylene selectivity of 93.00% and propane conversion of 32.00%. Experimental determination of propylene selectivity is consistent with RSM predictions, confirming the model's reliability and credibility.

The selectivity and stability of Pt?based catalysts can be improved by adjusting the active phase by adding additives. The active phase of Pt?based catalyst was regulated by changing n(Ga)/n(Pt) with Ga as an additive and characterized by BET, FT-IR, TG, H₂-TPR, etc. The n(Ga)/n(Pt) of the active phase was optimized under the reaction temperature of 580 ℃, volume space velocity of 2 000 h^-1 and hydrogen?hydrocarbon ratio (volume ratio of hydrogen to propane) of 1. The results show that the Pt in the Pt7Ga/Al₂O₃ catalyst has the smallest particle size and the best dispersion.The Pt7Ga/Al₂O₃ catalyst has the best dehydrogenation performance, and the propylene selectivity of the reaction for 3 h was 90.98%, which was 3.01% higher than that with the PtSn/Al₂O₃ catalyst. The regulation of Ga can enhance the interaction force between Pt and Al₂O₃ support, lower the acidity of catalyst and the degree of graphitization of catalyst carbon deposition.