Sulfur-doped Pt/C catalyst for propane dehydrogenation with improved atomic utilization and stability

Abstract

Atomically well-dispersed platinum catalysts play a vital role in various chemical processes such as direct dehydrogenation of propane (PDH), due to their high performance originated from high atom utilization. However, these catalysts suffer from complex preparation methods, and preparing atomically dispersed Pt-based catalysts with feasible methods remains challenging. Herein, we report a convenient method to prepare efficient atomically dispersed Pt/C catalysts for PDH by sulfur doping into the carbon support by simple cyclohexane impregnation method. The prepared atomically well-dispersed catalysts possess strong interactions between Pt and carbon support, which led to improved exposure of active sites and higher propylene formation rate compared to that without sulfur doping. Sintering of the Pt species was also inhibited and stability was improved by 47%. Propylene selectivity also showed a positive correlation with the amount of sulfur doping. The propane conversion first increased and then decreased, which was due to the loss of sulfur during the reaction that caused the agglomeration of Pt and the evolution of structure. It was found that the maximum catalytic activity appeared with Pt clusters of ∼ 0.71 nm with an average Pt-Pt coordination number of 3.1 and Pt-Pt bond distance of 3.09 Å.