Self-adaptive structure and catalytic performance of the Pt–Sn/Al2O3 propane dehydrogenation catalyst regenerated by dichloroethane oxychlorination

Abstract

Oxychlorination regeneration is an important and effective regeneration method for Pt based catalysts for propane dehydrogenation. Cl₂ and HCl are usually adopted as the chlorine source, which may jeopardize equipment and impair health seriously. A safer and less corrosive chlorine source, dichloroethane, is applied to oxychlorination regeneration of a series of Pt–Sn/Al₂O₃ catalysts after oxidation treatment. The catalysts are characterized by H₂-TPR, CO-DRIFTS, HAADF-STEM, XPS, and UV-vis DRS and their catalytic performances are also tested. It's found that the catalyst structures are self-adaptive for catalyzing the propane dehydrogenation reaction during the oxidation and oxychlorination treatment, in which Sn species combines with the alumina support in the ionic state and Pt is highly dispersed through an oxychloroplatinum complex. Pt migrates to sites having a stronger interaction with the support, leading to higher activity and selectivity. The performance of the regenerated catalyst is a function of oxychlorination conditions, indicating the possible influence of the coordination of chloride species with Pt on catalytic performance.