Ultra high Mo dispersion on SBA-16 mesoporous silica modified with TiO2 for HDS catalysis processes. A XAFS study

J. M. RAMALLO-LÓPEZ; ANDRINI, L.; REQUEJO, F. G.; KLIMOVA, T.; DOMÍNGUEZ, J. M.; RODRÍGUEZ, J. A.

La Plata

Congreso; 35th Anniversary of Hyperfine interactions at La Plata International Workshop; 2005

Mesoporous hybrid materials constitute a very exciting field in materials chemistry. Potential applications, in catalysis in particular, are promising due to their high surface area and their narrow pore size distribution as well as the diversity of functional groups which they can contain. The a-TiO2 (anatase) has been successfully applied as a support for hydrotreating due to its high intrinsic activity and capacity to generate a favourable morphology of MoS2 phases, metal support interactions as well as reducibility or sulfidability. In the present work, SBA-type supports were used to extend MoO3 dispersion in order to have nanometric domains for studying their HDS activity. These materials were studies by X-ray Absorption Fine Structure (XAFS) and High Resolution Electron Microscopy (HREM). A series of Ti-modified SBA-16 supports and the respective Mo catalysts were prepared, and their catalytic properties evaluated in the 4,6-dimethyldibenzothiophene (4,6-DMDBT) HDS reaction. The pre-edge region of XANES Ti K-edge spectra and HREM indicate the presence of nanosized crystallites of a-TiO2, while XANES and EXAFS Mo K-edge spectra indicate the higher dispersion of MoO3 for Ti-modified SBA-16 supports.