Mesoporous aluminophosphate materials: influence of method of preparation and iron loading on textural properties and catalytic activity

Abstract

In this paper the influence of the method of preparation and the iron loading on the textural properties and surface acidity of Iron aluminophosphates (FeAlP), [Fe x Al0.95P1, x = 0.01 mol−0.1 mol] was studied in order to learn how the preparation conditions and iron loading affect catalyst activity in transesterification reaction between diethyl malonate and benzyl alcohol. The catalysts were characterized by BET surface area, N2 sorption studies, NH3-TPD pXRD, SEM, and. FT-IR. Significant differences in the texture, surface acidity and adsorptive properties of FeAlP catalysts were found showing the influence of the preparation conditions and iron loading on the textural and surface properties of these catalysts. The textural and surface properties are correlated in the transesterification reaction between diethyl malonate and benzyl alcohol. FeAlP with 0.025 mol iron loading prepared by drop wise addition of ammonia, resulted a mesoporous material with uniform pore diameter (5–18 nm), higher surface area and higher surface acidity and hence catalytic activity towards the formation of Dibenzyl malonate. Fast addition of ammonia produced nonuniform porous material with lower surface acidity and low transesterification activity. Urea hydrolysis method yielded nonuniform porous materials with low surface area as well acidity.