Influence of preparation method on the activity of molecular sieve KA catalysts modified with zinc and phosphorus oxides in the non-oxidative thermocatalytic conversion of ethanol to aromatic hydrocarbons

Autor: G.E. Yergaziyeva, М.М. Mambetova, K. Dossumov
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: South African Journal of Chemical Engineering, Vol 43, Iss , Pp 60-66 (2023)
Druh dokumentu: article
ISSN: 1026-9185
DOI: 10.1016/j.sajce.2022.10.001
Popis: The activity of catalysts based on KA modified with zinc and phosphorus oxides and the effect of the method of catalyst preparation on its activity in the non-oxidative thermocatalytic conversion of ethanol to aromatic hydrocarbons was studied in this work. The ZnO-P2O5/KA catalyst was prepared by capillary impregnation and solution-combustion methods and characterized by SEM, TEM, TPD-NH3, and TPR-H2. The results showed that the method of preparation affects both the reducibility, dispersity, as well as the acidity of the catalyst. The preparation of the ZnO-P2O5/КА catalyst by the ''solution combustion'' method, in comparison with capillary impregnation, leads to an increase in the dispersion of particles. In the composition of the ZnO-P2O5/КА (SC) catalyst, nanoparticles with sizes from 2 nm are observed. The results of TPD-ammonia showed that catalysts based on KA modified with zinc oxides have weak and strong Lewis acid sites, and Bronsted acid sites. Modification of ZnO-P2O5/КА with phosphorus oxide leads to an increase in the number of weak and strong acid sites. The highest ethanol conversion (85%) and the concentration of aromatic hydrocarbons (23 vol.%) was obtained for the ZnO-P2O5/КА (SC) catalyst, which has the highest acidity of 1206 µmol/g.
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