Improved catalytic performance in propane dehydrogenation of PtSn/γ-Al2O3 catalysts by doping indium

• Improved PtSn/γ-Al2O3 catalysts in propane dehydrogenation by doping indium.
• Doping indium leads the acidity of the supports to decrease.
• Pt particles become smaller with addition of indium.
• Doping indium in PtSn/γ-Al2O3 catalysts could suppress side reactions.

Bimetallic PtSn/γ-Al2O3 catalysts promoted by doping indium(In) for propane dehydrogenation are investigated with several state-of-art characterizations such as BET, XRD, NH3-TPD, TEM, XPS, H2-TPR and TPO. The results show that the indium addition evidently improves the catalytic performances and stability of PtSn/γ-Al2O3 catalysts. The NH3-TPD profiles verify a decrease in acidity for the supports with the addition of indium. Metallic Sn and In or PtSn alloy and PtIn alloy are detected by XPS spectra on the catalysts after reduction. The presence of indium in the PtSn/In–Al2O3 catalysts not only could maintain the catalytic active and propylene selectivity, but also could suppress the hydrogenolysis reaction during propane dehydrogenation process. The high activity (conversion > 41.0%) and perfect propylene selectivity (selectivity > 96%) are obtained in propane dehydrogenation after reaction for 53 h.