Effect of Synthesis Method on the Properties of Mesoporous CuO/Al2O3 Catalysts

A series of mesoporous Cu-incorporated Al2O3-based catalysts were synthesized via the sol–gel method using dodecylamine (DDA) and polyethyleneimine (PEI) as templates. The catalysts were characterized using low-temperature N2 adsorption–desorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), H2 temperature-programmed reduction (H2-TPR), and NH3 temperature-programmed desorption (NH3-TPD). A CuO/Al2O3 catalyst prepared by wetness impregnation of commercial Al2O3 was used as a reference sample. All the samples were reduced and tested in the vapor-phase reductive alkylation of nitrobenzene with methanol (RANM) using a flow-type reactor. With polyethylenimine as a template, the synthesized catalyst possessed ordered cylindrical pores and a specific surface area up to 260 m2/g, whereas the catalyst prepared using dodecylamine had slit pores and a specific surface area of 270 m2/g. The catalytic activity of mesoporous Cu/Al2O3 catalysts in RANM was found to strongly depend not only on the Cu loading but also on the shape and volume of the support’s pores.