Green synthesis of methanol over zeolite based Cu nano-catalysts, effect of Mg promoter

Abstract

Zeolite based nano-catalysts with 5 wt % Cu were synthesized by precipitation method. In order to assess the role of Mg as catalyst promoter, the synthesized nano-catalysts were doped with 0.1, 0.2, 0.3 and 0.4 wt % of Mg. Different analytical techniques were employed to investigate the physicochemical profile of the promoted nano-catalysts. Thermal stability of the promoted nano-catalysts was studied by thermogravimetric analysis (TGA). X-ray diffraction studies revealed a very fine crystalline nature of the promoted nano-catalysts. Morphological investigations performed by field emission scanning electron microscopy (FESEM) showcased well dispersed Cu, Mg bimetallic particles over the zeolite support. Nitrogen adsorption–desorption analysis displayed the promoting role of Mg by recording increase in BET surface area as consequent of Mg addition to the Cu based zeolite nano-catalysts. Activity of the promoted nano-catalysts for pure CO2 hydrogenation was evaluated in slurry reactor. Activity studies of the promoted nano-catalysts demonstrated rise in methanol synthesis rate by incrementing the Mg loadings to the Cu based zeolite nano-catalysts. The structure activity relationship revealed BET surface area as a main parameter controlling the rate of methanol synthesis reaction.