Enhanced Pt dispersion and catalytic properties of NaCl-promoted Pt/MFI zeolite catalysts for propane dehydrogenation

A simple and scalable method is presented for preparing propane dehydrogenation catalysts with superior catalytic properties. Pt distribution is significantly improved when the platinum precursor and a large amount of NaCl are introduced into the MFI zeolite by impregnation, and after calcining and fixing the active components in the insoluble form, the excess of inert salt is washed with water. NaCl promotes Pt dispersion, prevents sintering during calcination, and effectively suppresses zeolite acidity. Washing after the calcination of Pt-containing catalysts further increases the catalyst activity and stability due to the redispersion of water-soluble chlorinated Pt compounds. High external surface acid site concentrations, Na/Pt atomic ratios of 40–70, calcination temperatures of 400–500 °C, washing with water, and the order of component introduction when the excess NaCl and the precursor of Pt are calcined jointly contribute to improved Pt dispersion and catalyst stability. [Display omitted] •Impregnation-calcination-washing method of Pt catalysts preparation is proposed.•Calcination of the Pt precursor with an excess of NaCl increases the dispersion of Pt.•NaCl excess contributes to stability of propane dehydrogenation MFI-zeolite catalysts.•Washing after calcination improves the activity and stability of Pt/MFI catalysts.