Structural Determination of Nanodispersed Pd-Catalysts
Today, great attention is attracted to development of highly effective approaches of converting renewable biomass into energy resources as biofuels. Some spirit compounds, such as ethanol, butanol, pentanol, glycerine, being biomass fermentation products, may be used as fuel components, both without any treatment and after catalytic converting, that provides production of more effective fuel components. The presented work is devoted to a study of the state and local structure of original nano-dispersed catalytic low-percentage systems PdMe (Me=Zn, Co, Mn, Ag) , used for production of alkanes or olefins fractions С4-С12+ which components of biofuels obtained from biomass fermentation products. Initial samples of catalysts were prepared by impregnation and zol-gel methods from original mono- and hetero-metallic precursors located on the oxide supports. All XANES and EXAFS spectra of the studied samples were recorded at Siberian Synhroton and Terahertz Radiation Center (SSTRC, Novosibirsk).Genesis of the local structure of the studied catalytic nanosystems was characterized in detail. The interatomic distances and corresponded coordination numbers were revealed. All possible structural models were discussed. Relations between their catalytic properties, local structure distortions and state of metal components were demonstrated. It was found out that active components of all studied systems were highly dispersed onto the oxide support surface and strong interaction with the support took place, resulting in formation of mixed surface MeOx - support oxides.