Fries Rearrangement of Phenyl Acetate over ZSM-5 Based Catalysts

Abstract

Catalysts based on samples of ZSM-5, differing in Si/Al ratio were applied in the Fries rearrangement of phenyl acetate. Experiments were carried out in batch reactors at 180 °C and continuously at various temperatures both in liquid phase and gas phase. A reaction scheme is proposed.

Retention of the octahedral metal framework of Nb and Mo halide clusters in catalytic decomposition of phenyl acetate to phenol and ketene

“…Consequently, a high-performance catalyst for the Fries rearrangement is expected to have a stabilizing capacity for the cations. Increasing selectivity for the Fries rearrangement [26,27] as well as increasing p/o ratio of hydroxyacetophenone [77] with decreasing reaction temperature agrees with this interpretation. Liquid phase reaction exhibited better selectivity for the Fries rearrangement compared with the gas phase reaction [27], in which no solvation for the cations is present.…”

“…Rapid deactivation of zeolitic catalysts particularly in the gas phase reaction owing to coke formation has been reported in the initial stage of this reaction [27]. The deactivation was increased by an increase in the reaction temperature; a similar temperature effect is also reported on H-ZSM-5 for this reaction [26]. The catalytic activity will henceforth be discussed at 3 h after reaction started.…”

“…Because the carbonyl oxygen strongly coordinates to the Lewis acid center [25], hydrolysis of the Lewis acid is necessary for the isolation of the products. In order to overcome this disadvantage, solid Brønsted acids such as H-Beta zeolite [26][27][28][29], H-Y zeolite [28,30,31], H-ZSM-5 [26][27][28][30][31][32][33], HF/Al 2 O 3 [30], and Nafion-H [34], a resin containing the CF 2 CF 2 SO 3 H group, are used as the catalyst. However, the selectivity for o-and p-hydroxyacetophenone is not high, and in almost all cases the main product is the decomposition product, phenol.…”

Catalytic Reactions over Halide Cluster Complexes of Group 5–7 Metals

“…Because the carbonyl oxygen strongly coordinates to the Lewis acid center [39], hydrolysis of the Lewis acid is necessary for the isolation of the products. In order to overcome this disadvantage, solid Brønsted acids such as H-Beta zeolite [40][41][42][43], H-Y zeolite [42,44,45], H-ZSM-5 [40][41][42][44][45][46][47], HF/Al 2 O 3 [44], and Nafion-H [48], a resin containing the -CF 2 CF 2 SO 3 H group, are used as the catalyst. However, the selectivity for o-and p-hydroxyacetophenone is not high, and in almost all cases the main product is the decomposition product, phenol.…”