Chapter 4. Design of Metal-modified Zeolites and Mesoporous Aluminosilicates and Application in the Synthesis of Fine Chemicals

Different catalyst synthesis methods determine the physicochemical and catalytic properties of the prepared materials. The design of suitable catalytic active sites is important to increase the activity and to improve selectivity for the desired product. Biomass derived terpenes and their oxides (e.g. α-pinene oxide) are important platform building blocks for the pharmaceutical and fine chemical industries. Transformation of α-pinene oxide to a fragrance chemical, campholenic aldehyde, is promoted by the Lewis acidic nature of the catalyst. The isomerization of α-pinene oxide to campholenic aldehyde was studied over Co-modified Beta- and Y-zeolites as well as over silica, alumina and mesoporous H-MCM-48 catalysts. The Co-modified catalysts were characterized using powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), elemental analysis using energy dispersive X-ray spectroscopy (EDX), nitrogen sorption analysis to analyze the porosity, X-ray photoelectron spectroscopy (XPS) to study the Co oxidation states, temperature programmed desorption (TPD)-NH3 and Fourier transform infrared spectroscopy (FTIR)-pyridine to measure the acidic properties. Co-H-Beta-150, Co-H-Beta-25, Co-H-Y-12, Co-H-Y-80, Co-H-MCM-48 catalysts gave rise to a high conversion (>62%) of α-pinene oxide. The Co-H-Y-80 zeolite and the Co-MCM-48 mesoporous catalysts exhibited a 51% and 45% yield of campholenic aldehyde, respectively.