Cerium-doped UiO-66-supported Pd catalysts: activity enhancement and deactivation pathways in the carbonylation of methyl nitrite to DMC.

For the carbonylation of methyl nitrite (MN) to dimethyl carbonate (DMC), a series of Ce(x)-UiO-66 were synthesized and utilized as supports for Pd/Ce(x)-UiO-66 catalysts. The characteristics of the carriers were investigated using XRD, SEM, TG, NH3-TPD and BET analyses. The results showed that doping cerium in the UiO-66 significantly enhanced the catalytic activity by improving the surface area, acidity and CO adsorption of the catalysts. Ce(0.1)-UiO-66, with the highest thermal stability (547.26 °C), presented the highest catalytic stability in DMC synthesis. It was proven that the damage of C[double bond, length as m-dash]O and the migration of Pd atoms occurred due to the replacement of ligands and metal clusters, which led to catalytic deactivation.