Methane conversion to syngas over Ni/Y2O3 catalysts — Effects of calcination temperatures of Y2O3 on physicochemical properties and catalytic performance

Abstract

Ni/Y2O3 catalysts, with Y2O3 prepared by the conventional precipitation method and calcined at different temperatures, were characterized by BET, TPR, XRD, NH3-TPD, CO2-TPD and TGA, and evaluated in the reaction of partial oxidation of methane. The results showed that, cubic phase Y2O3 could be obtained by calcinating the precursor at temperatures higher than 500°C, and the specific surface area of Y2O3 was the largest when the calcination temperature was 500°C. NH3-TPD and CO2-TPD profiles showed that, calcination temperature of Y2O3 influenced the amount of acidic and basic sites over Y2O3 support. After the loading of Ni, the strength and the amount of basic sites were almost the same over all the Ni/Y2O3 catalysts, which might be due to the hydrolysis of Y2O3 in the aqueous solution during the impregnation process. TPR results showed that, Y2O3 could be partially reduced, and the interactions between Ni and Y2O3 increased with the increase of Y2O3 calcination temperatures. In the reaction of partial oxidation of methane, all the Ni/Y2O3 catalysts were stable and exhibited high anti-carbon deposition ability.