Effect of silicates on the structure of Ni-containing catalysts obtained from hydrotalcite-type precursors

Abstract

New nickel hydrotalcite-like compounds with silicates as interlayer anions used as catalyst precursors in the catalytic partial oxidation of methane were prepared by the coprecipitation method. The properties of these materials were compared with those of compounds obtained from carbonate-containing materials. The precursors and calcined samples were characterized by powder X-ray diffraction, FT-IR and Vis/UV/NIR spectroscopies, thermal analyses (DTA and TG), temperature programmed reduction (TPR) and N 2 adsorption/desorption at −196 °C. The results show that the incorporation of silicates in the lamellar compounds modifies the structural and textural properties of the precursors. After calcination, silicates – which are non-volatile anions – contribute to the final structure of the catalysts, which form a new forsterite-like phase, increasing their specific surface area but not altering the reducibility of the nickel species.