Co catalysts supported on SiO2 and γ-Al2O3 applied to ethanol steam reforming: Effect of the solvent used in the catalyst preparation method

Cobalt catalysts were prepared on supports of SiO2 and γ-Al2O3 by the impregnation method, using a solution of Co precursor in methanol. The samples were characterized by XRD, TPR, and Raman spectroscopy and tested in ethanol steam reforming. According to the XRD results, impregnation with the methanolic solution led to smaller metal crystallites than with aqueous solution, on the SiO2 support. On γ-Al2O3, all the samples exhibited small crystallites, with either solvent, due to a higher Co-support interaction that inhibits the reduction of Co species. The TPR results were consistent with XRD results and the samples supported on γ-Al2O3 showed a lower degree of reduction. In the steam reforming of ethanol, catalysts supported on SiO2 and prepared with the methanolic solution showed the best H2, CO2 and CO selectivity. Those supported on γ-Al2O3 showed lower H2 selectivity.