| 초록 |
The direct conversion of cellulose into polyols in the presence of hydrogen was examined over Ni/W/SiO2 catalysts to establish the effects of average pore size of support and reduction temperature on the catalytic performance. The crystalline particle size of W, determined by X-ray diffraction (XRD), generally increased with increase in the average pore size of support and reduction temperature for Ni/W/SiO2. The yield of polyols such as sorbitol, mannitol, erythritol, ethylene glycol, and 1,2-propanediol increased on decreasing the crystalline particle size of W in Ni/W/SiO2. The individual catalytic activity of Ni/W/SiO2 was much better than that of the combined catalyst systems, i.e., Ni/SiO2+W and Ni/SiO2+WO3. The oxidation state effect of nickel and tungsten in Ni/W/SiO2 catalyst on the catalytic performance was also investigated. The reduced and oxidized Ni/W/SiO2 catalysts were found to be effective in forming polyols and organic acids, respectively. |
