Base property of high silica MFI zeolites modified with various alkyl amines

A series of novel material, basic MFI-type zeolites, were prepared by modification with methylamine (MA), dimethylamine (DMA), trimethylamine (TMA), ethylamine (EA), n-propylamine (PA), n-butylamine (BA) and n-tripropylamine (TPA) on high silica MFI zeolite at 200 degrees C. In situ FT-IR was used to inspect the incorporation of N into the framework, and TG/DTG was used to investigate the decomposition of the organic groups trapped in the modified zeolites. The base property of the materials measured with temperature programmed desorption of CO2 (CO2-TPD) are 1-2 order of magnitude stronger than that of the raw high silica zeolite, and related to the number of alkyl group and the size of carbon chain in the alkyl amine (-NHR1, -NR1R2; R-1, R-2 = C-1-C-4) used in the modification. Furthermore, the materials pre-heated at different temperatures results in obvious variation of the base property. (c) 2006 Elsevier Inc. All rights reserved.