“Iron stabilized gold catalysts supported on mesopouros SBA-15”

Highly dispersed gold catalysts supported on different solids have shown high catalytic activity towards many reactions of industrial and environmental importance. When silica is used as a support it is very difficult to obtain an optimal gold dispersion degree due to the low affinity of gold for SiO2. Mesoporous SBA-15, with a highly ordered 2D hexagonal structure and well defined pore size and thicker walls, seems to be an ideal candidate in order to obtain a strong confinement of gold nanoparticles. Several studies demonstrated the addition of an iron component to gold supported catalysts brings a beneficial effect in terms of enhanced activity, selectivity and resistance to deactivation. In our previous works we demonstrated it is possible to synthesize catalysts containing iron stabilized gold nanoparticles with a controlled size and an intimate contact between gold and iron using bimetallic carbonyl clusters as precursors of the active phase. Thus, in the present work we combined the use of SBA-15 and the carbonyl clusters preparation method. Bimetallic iron-gold catalysts were prepared on SBA-15, starting from the bi-metallic carbonyl cluster salt, [NEt4][AuFe4(CO)16], aiming to obtain highly dispersed gold nanoparticles within the pores of SBA-15 and stabilized by an iron layer. Moreover, in order to increase the adsorption and the anchoring of the cluster on the support, SBA-15 surface was functionalised by amino groups through reaction with (3-Aminopropyl)triethoxysilane. Prepared catalysts were characterized and tested in the total oxidation of methanol.