Influence of alumina precursor on the physico-chemical properties of V-Sb-P-W/Al sub(2)O sub(3) catalyst studied for the ammoxidation of propane

• Published in: Applied catalysis. A, General Vol. 512; pp. 52 - 62
• Main Authors: Pasupulety, Nagaraju, Driss, Hafedh, Zaman, Sharif F, Alhamed, Yahia Abobakor, Alzahrani, Abdulrahim Ahmed, Daous, Muhammad A, Petrov, Lachezar
• Format: Journal Article
• Language: English
• Published: 25.02.2016
• Subjects: Aluminum oxide; Catalysts; Formations; Precursors; Propane; Propylene; Surface chemistry; X-ray photoelectron spectroscopy
• ISSN: 0926-860X
• DOI: 10.1016/j.apcata.2015.12.014

Influence of alumina precursor on active phase formation in V sub(1.0)-Sb sub(3.5)-P sub(0.5)-W sub(1.0)/50% Al sub(2)O sub(3) catalyst was studied for the ammoxidation of propane in the temperature range of 490-530 degree C at W/F = 2.8 g sub(cat) s ml super(-1). Three different alumina precursors such as, aluminum chloride (AlC), aluminum hydroxide (AlH) and aluminum nitrate (AlN) were employed in the study. The physico-chemical characterisitics of the synthesized catalysts were investigated by BET surface area-pore size method, XRD, FTIR, HAADF/EDS, NH sub(3) TPD-mass and XPS techniques. XRD result demonstrates AlPO sub(4) phase for all the three catalysts which was likely due to P interaction with alumina precursor. Formation of propylene and acrylonitrile (ACN) in this study was influenced by the nature of the active surface on Al sub(2)O sub(3) synthesized from different precursors. Among the catalysts, AlC exhibited greater propane conversion (76%) and ACN selectivity (28%) at 530 degree C. The higher activity of AlC was associated with (i) active surface enriched in V-Sb-W phase as established by XPS and HAADF/EDS results (ii) higher adsorption ability for NH sub(3) in the presence of residual chloride (coming from AlCl sub(3)) followed by efficient nitrogen insertion in the intermediate molecule of propane to yield ACN. The surface with Sb-W-O related phase in AlN and AlH possibly contributes to the degradation of adsorbed propane/propylene and NH sub(3) to yield methane, ethane, ethylene, CO sub(x) and NO sub(x). To our knowledge, this is the first report for the influence of alumina precursor on the active phase formation in V-Sb-P-W/Al sub(2)O sub(3) catalyst studied for the propane ammoxidation. Propane amm(oxidation) to propylene (C sub(3)H sub(6)) and acrylo nitrile (C sub(3)H sub(3)N) on V-Sb-P-W/Al sub(2)O sub(3) catalyst.