Mesoporous HBeta zeolite obtained via zeolitic dissolution–recrystallization successive treatment for vapor-phase Doebner–Von Miller reaction to quinolines

Abstract

A reassembled HBeta zeolite (HBeta-Ct) was obtained via zeolitic dissolution–recrystallization successive treatment, and characterized by means of XRD, FT-IR, SEM, TEM, N₂ adsorption–desorption as well as NH₃-TPD techniques. The characterization results manifested that the HBeta-Ct zeolite possessed more mesopores and less acid than the parent one. Catalyst activities of the parent and reassembled HBeta catalysts were investigated in detail in the vapor-phase Doebner–Von Miller reaction to quinolines. The results demonstrated that the reassembled HBeta zeolite showed enhanced catalyst stability and improved anti-alkylation ability. This is probably due to the existence of mesopores on the catalyst which strengthened the diffusion of bulky products from pore channels in the zeolite. Meanwhile, the decreased acid amount over the catalyst can also retard the alkylation process to generate alkylquinolines as well as the acid-induced polymerization reaction to form coke. Besides, the HBeta-Ct catalyst also exhibited good regenerability in the Doebner–Von Miller reaction.