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.