Synthesis of 2-Methylpyrazine Over Highly Dispersed Copper Catalysts

Abstract

A series of CuCoAl catalysts were synthesized by co-precipitation and impregnation methods, tested in synthesis of 2-methylpyrazine (2-MP) and characterized by X-ray diffraction, N2 adsorption, thermo-gravimetry analysis, H2-temperature-programmed reduction, dissociative N2O adsorption and temperature-programmed oxidation. The precursors prepared by co-precipitation method shows a well-crystallized hydrotalcite. The study proves that the calcination temperature of hydrotalcite has a significant effect on the catalyst surface area, crystallite size and copper dispersion. In comparison with catalyst prepared by impregnation, the catalyst prepared by co-precipitation method calcined at 500 °C exhibits higher specific surface area, higher copper dispersion and the better reducibility. Consequently, CuCoAl catalyst derived from hydrotalcite is more active and selective for synthesis of 2-MP. Moreover, it shows the better stability due to the good resistance to coke formation. A novel solid base catalyst containing copper and spinel was prepared by the thermal decomposition of Cu–Co–Al hydrotalcite-like compounds for synthesis of 2-methylpyrazine