Quantum Mechanics Calculation of Molybdenum and Tungsten Influence on the CrM-oxide Catalyst Acidity

Authors : Oyegoke TOYESE, Fadimatu DABAİ, Adamu UZAİRU, Baba JİBRİL

Pages : 297-311

Doi:10.17350/HJSE19030000199

View : 13 | Download : 6

Publication Date : 2020-12-31

Article Type : Research Paper

Abstract :Semi-empirical calculations were employed to understand the effects of introducing promoters such as molybdenum insert ignore into journalissuearticles values(Mo); and tungsten insert ignore into journalissuearticles values(W); on chromium insert ignore into journalissuearticles values(III); oxide catalyst for the dehydrogenation of propane into propylene. For this purpose, we investigated CrM-oxide insert ignore into journalissuearticles values(M = Cr, Mo, and W); catalysts. In this study, the Lewis acidity of the catalyst was examined using Lewis acidity parameters insert ignore into journalissuearticles values(Ac);, including ammonia and pyridine adsorption energy. The results obtained from this study of overall acidity across all sites of the catalysts studied reveal Mo-modified catalyst as the one with the least acidity while the W-modified catalyst was found to have shown the highest acidity signifies that the introduction of Mo would reduce acidity while W accelerates it. The finding, therefore, confirms tungsten insert ignore into journalissuearticles values(W); to be more influential and would be more promising when compared to molybdenum insert ignore into journalissuearticles values(Mo); due to the better avenue that is offered by W for the promotion of electron exchange and its higher acidityinsert ignore into journalissuearticles values(s);. The suitability of some molecular descriptors for acidity prediction as a potential alternative to the current use of adsorption energies of the probes was also reported.
Keywords : Molecular Descriptor, Metallic Oxide, Semi Empirical Calculation, Chromium Oxide, Lewis Acidity, Molecular Probe