Abstract
Number of methods have been reported in the literature for the preparation of dimethyl carbonate (DMC) as an important chemical compounds typically applied in methylation and carbonylation reactions. Recently a particular attention has been paid to the reaction of methanol with carbon dioxide as an alternative to other syntheses involving hazardous and toxic components [1]. In such a reaction system a highly active catalyst is required to make this method competitive in comparison with other types of synthesis routes.In this work we report on the preparation of ceria-zirconia mixed-oxides, which are considered as particularly promising for meeting the requirements leading to performable DMC synthesis. The synthesis strategy is based on the preparation of a supported catalyst starting from polymeric sols/gels (prepared by the Pechini method) which are subsequently deposited/infiltrated uniformly on/in inert porous ceramic support. Before performing the catalyst deposition step unsupported CeO2-ZrO2 powders have prepared and characterized in order to confirm the formation of the required uniform mixed-oxide with both defined composition and textural characteristics. The optimized sol formulations were subsequently used for the impregnation of the porous ceramic supports. During deposition, the sol viscosity was also controlled in order to limit the formation of a surface coating which was shown to suffer from attrition. The as-prepared catalyst has been tested for DMC synthesis in a continuous stirred tank reactor evaluating its catalytic activity as a function of the quantity and specific surface area of the active phase deposited on/in the porous ceramic support. [1] S. T. Hong et al., Synthesis of dimethyl carbonate from methanol and supercritical carbon dioxide, Research on Chemical Intermediates 32 (2006) 737-747.