Catalysis Today, Vol.325, 11-17, 2019
Ca/MCF catalysts - The impact of niobium and material structure on basicity
The mesostructured cellular foams (MCF and NbMCF) were modified by post-synthesis procedure with calcium and niobium in order to obtain basic catalysts. The materials obtained were characterized by: N-2 adsorption, XRD, XPS, CO2-TPD as well as in a test reaction, i.e. cyclization and dehydration of 2,5-hexanedione. The highest concentration of surface calcium species was detected for CaNb/MCF sample, which also showed the presence of hydroxide and carbonate species on its surface. The catalytic activity was investigated in ethyl butyrate trans-esterification with methanol. Good correlation of methyl butyrate formation was found with the number of surface calcium species and basicity of the material obtained. Deactivation of catalysts was thoroughly investigated revealing the important role of preservation of crystallinity of the modifier on a given material surface.