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 °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; R1, R2 = C1–C4) used in the modification. Furthermore, the materials pre-heated at different temperatures results in obvious variation of the base property.