Optimization of PtSnK/Al2O3 isobutane dehydrogenation catalyst prepared by an impregnation-reduction method

•A simple impregnation-reduction method was developed to prepare PtSnK/Al2O3 catalyst.•The PtSnK/Al2O3 catalyst showed high activity and stability in isobutane dehydrogenation.•Taguchi method was adopted to optimize the major influencing parameters of catalyst preparation.•Verifying experiment demonstrated the correctness of the final optimum result.

In this study, a series of PtSnK/Al2O3 catalysts were prepared by an impregnation-reduction method and employed as a catalyst in an isobutane dehydrogenation reaction. In order to improve the dehydrogenation performance of isobutane, the preparation conditions of the PtSnK/Al2O3 catalysts were optimized by the Taguchi method of experimental design. The effects of four variables, mass ratio of platinum to tin, concentration of H2PtCl6, calcination temperature, and K loading (mass fraction) at four levels were investigated. The results revealed that the order of the affecting factors was mass ratio of platinum to tin > K loading > calcination temperature > concentration of H2PtCl6. The optimum preparation conditions were as follows: mass ratio of platinum to tin 1:1, concentration of H2PtCl6 7.72 × 10−4 mol/L, calcination temperature 500 °C, and K loading 0.8%. The optimized PtSnK/Al2O3 catalysts exhibited good catalytic performance for isobutane dehydrogenation. The average isobutane conversion, selectivity toward isobutene, and deactivation parameter were 46.59 ± 0.83%, 95.37 ± 0.49%, 1.45 ± 0.74%, respectively.