Abertura de anéis naftênicos utilizando carbetos de metais de transição

Abstract

This work aimed to study the application of transition metal carbides supported on a commercial USY zeolite in naphthenic ring opening reaction, by varying carbide content on the support and the transition metal, obtaining the catalytic evaluation of four catalysts: 20 % Mo2C/USY, 10 % Mo2C/USY, 20 % W2C/USY and 10 % W2C/USY. Oxide precursors were prepared via incipient wetness impregnation and the supported carbides were synthesized from them using the programmed temperature carburizing methodology (TPC). Oxide precursors and catalysts were characterized by X-Ray Diffraction, N2 adsorption, TPC and CO chemisorption. Analysis from CO chemisorption indicated possible agglomeration of the carbide crystallites as the carbide content on the support increased. Previously to the reaction, the catalysts were activated in situ. Catalytic tests were performed between 260 ºC and 300 ºC, pressure 3,5 MPa. H2/decaline molar ratio = 100 mol/mol and WHSV = 0,44 h-1 . It was observed that a lower carbide load on the support presents a better performance on decalin conversion and also on the results of ROP selectivity. Additionaly, it was verified that the acidity of the support influenced significantly in the reaction results with high yields of isomerization products.