Effects of Ga doping on Pt/CeO2-Al2O3 catalysts for propane dehydrogenation.

This paper describes catalytic consequencesThis paper describes catalytic consequences of Pt/CeO₂-Al₂O₃ catalysts promoted with Ga species for propane dehydrogenation. A series of PtGa/CeO₂-Al₂O₃ catalysts were prepared by a sequential impregnation method. The as-prepared catalysts were characterized employing N₂ adsorption-desorption, X-ray diffrtaction, temperature programmed reduction, O₂ volumetric chemisorption, H₂-O₂ titration, and transmission electron microscopy. We have shown that Ga³⁺ cations are incorporated into the cubic fluorite structure of CeO₂, enhancing both lattice oxygen storage capacity and surface oxygen mobility. The enhanced reducibility of CeO₂ is indicative of higher capability to eliminate the coke deposition and thus is beneficial to the improvement of catalytic stability. Density functional theory calculations confirm that the addition of Ga is prone to improve propylene desorption and greatly suppress deep dehydrogenation and the following coke formation. The catalytic performance shows a strong dependence on the content of Ga addition. The optimal loading content of Ga is 3 wt %, which results in the maximal propylene selectivity together with the best catalytic stability against coke accumulation. © 2016 American Institute of Chemical Engineers AIChE J, 62: 4365-4376, 2016 [ABSTRACT FROM AUTHOR]