NOVEL NI-GA ALLOY BASED CATALYST FOR CONVERTING CO2 TO METHANOL

摘要

Novel and advanced catalysts based on Ni-Ga alloy were prepared through co-condensation method with and without evaporation of water solvent for converting CO2 to methanol. The co-condensations used Ni(NO3)(2) and Ga metal as beginning precursors under alkaline media. Various Ni/Ga molar ratios and temperature of the co-condensation-evaporation method were investigated in order to obtain Ni5Ga3 alloy composition as active phase for the catalysts. The results confirmed that the stoichiometry of 5/3 could be reached at the same molar ratio of the beginning precursors, and the suitable temperature of the method was 80 degrees C for a certain time of 24 h. The Ni-Ga based catalyst activity and selectivity were also tested in the conversion of CO2 to methanol at atmospheric pressure and 220 degrees C for different periods of time. The results showed that the catalyst was an excellent candidate for this process compared to other catalysts when exposing good selectivity over 90% during long periods of time. Many techniques were used including X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), X-Ray Photoelectron Spectroscopy (XPS), Nitrogen Adsorption-Desorption Analysis (BET), and Gas Chromatography (GC) to characterize the catalyst structure and the reaction performance, respectively.