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

Abstract

This paper describes catalytic consequencesThis paper describes catalytic consequences of Pt/CeO 2 -Al 2 O 3 catalysts promoted with Ga species for propane dehydrogenation. A series of PtGa/CeO 2 -Al 2 O 3 catalysts were prepared by a sequential impregnation method. The as-prepared catalysts were characterized employing N 2 adsorption-desorption, X-ray diffrtaction, temperature programmed reduction, O 2 volumetric chemisorption, H 2 -O 2 titration, and transmission electron microscopy. We have shown that Ga 31 cations are incorporated into the cubic fluorite structure of CeO 2 , enhancing both lattice oxygen storage capacity and surface oxygen mobility. The enhanced reducibility of CeO 2 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.

Structure and catalytic consequence of Mg‐modified VOx/Al2O3catalysts for propane dehydrogenation

“…Then, a mixture of 28 vol % propane and 28 vol % H 2 in N 2 was fed at a rate of 25 mL/min. The weight hourly space velocity (WHSV) of propane was 3 h −1 , which was generally used in relevant studies . Exhaust streams were analyzed using an online GC (2060) equipped with a flame ionization detector (Chromosorb 102 column) and a thermal conductivity detector (Al 2 O 3 Plot column).…”

“…Recently, growing production of shale gas drives the price of propane down, which makes the propane dehydrogenation (PDH) process commercially attractive for propylene production . Pt and CrO x are generally used as catalytically active materials in industrial PDH processes and they were extensively investigated . However, the high cost of Pt and the hypertoxicity of CrO x somehow restrict the development of PDH industry.…”

Thin Heterojunctions and Spatially Separated Cocatalysts To Simultaneously Reduce Bulk and Surface Recombination in Photocatalysts

“…Thei ntensities of the XRD peaks corresponding to Pt were very weak owing to the low loading (0.8 wt %b yI CP). [12] Thep ore size and Brunauer-Emmett-Te ller (BET) surface area of the PTIM-MSs were determined to be 5.3 nm (average pore size) and 288 m 2 g À1 ,respectively, by nitrogen adsorption measurements (Figure S6 b). These results indicate am esoporous structure,w hich allows for the penetration and transportation of reactants and products.…”

Density Functional Theory Investigation into the B and Ga Doped Clean and Water Covered γ-Alumina Surfaces

“…In addition, the electronic structures also change after the substitution of the Al atoms by the Fe atoms on the surface. Except for the incorporation of Fe into the alumina surface, the B and Ga atoms, which are often used as the trivalent substitution ions for the zeolites [15,16], are also used in experiments for the preparation of high performance catalysis and semiconductors [8,9,[17][18][19]. Kibar et al prepared nanostructured boron doped alumina catalyst support [20] and found that the morphology of the supports can be modified from cracked surface to nanosphere formation by the introduction of boron.…”

“…In order to improve the performance of the material, some heteroatoms were usually chosen to be incorporated into the -alumina bulk and surfaces [8,9]. For example, the Fe atom was usually used to improve the catalytic performance of -alumina [10].…”