Promoted ternary CuO-ZrO2-Al2O3 catalysts for methanol synthesis
Central European Journal of Chemistry
© Versita Sp. z o.o. catalysts promoted by palladium or gold were prepared and tested in CO hydrogenation reaction at 260°C under elevated pressure (4.8 MPa). The promotion effect of palladium or gold addition on the physicochemical and catalytical properties of CuO-ZrO 2 -Al 2 O 3 catalysts in methanol synthesis (MS) was studied. The catalysts were characterized by BET, XRD, TPR-H 2 , TPD-NH 3 methods. The BET results showed that the ternary system CuO-ZrO 2 -Al 2 O 3 had the largest specific
... e largest specific surface area, cumulative pore volume and average pore size in comparison with the promoted catalysts. The yield of methanol can be given through the following sequence: 5%Pd/CuO-ZrO 2 -Al 2 O 3 > CuO-ZrO 2 -Al 2 O 3 > 2%Au/CuO-ZrO 2 -Al 2 O 3 . We also found that the presence of gold or palladium on catalyst surface has strong influence on the reaction selectivity. The high selectivity of gold doped ternary catalyst is explained by the gold-oxide interface sites created on the catalyst surface and the acidity of those systems. The higher selectivity to methanol in the case of the palladium catalyst is explained by the spillover effect between Pd and CuO .