Catalytic Transfer Hydrogenation Performance of Magnesium-Doped ZrO2 Solid Solutions

Abstract

This is the first study to investigate the activity of a solid solution containing magnesium ions in a zirconia matrix in the catalytic transfer hydrogenation (CTH) of acetophenone with 2-pentanol. The results have shown that magnesium oxide is very highly active in CTH when physically mixed with zirconia. However, the same concentration of Mg2+ ions (Mg:Zr = 3:97) inserted into a zirconia lattice did not yield high activity in CTH. A higher concentration of Mg2+ ions (5%) was also tested in the two types of systems, i.e., a physical mixture of oxides and a solid solution. The increase in the concentration of Mg2+ ions in the physical mixture led to a pronounced increase in the activity of the system, whereas in the case of the solid solution it led to a slight decrease in activity. The impact of the zirconyl salt used in the synthesis was also examined, but showed little effect on the properties and activity of the systems. The study has also shown that the increase of the concentration of magnesium ions caused a decrease in the m-ZrO2 to t-ZrO2 ratio. Nevertheless, the rate of heating had an even bigger effect on this ratio.