A highly selective AU/TiO2 coated capillary microreactor for hydrogenation of alpha/beta-unsaturated aldehydes

A novel methodology has been successfully employed for the preparation of a catalytic coating within a silica capillary for the development of a new generation of versatile microchannel reactors. In this study, we focus on the development of mesoporous Ti02 thin films containing gold nanoparticles as active catalysts onto the inner walls of fused silica capillaries. The thickness of the resulting films was approximately 90 nm with an Au loading of 1 wt%. The selective hydrogenation of citral to the unsaturated alcohols in this Au/Ti02 coated capillary was studied at 343-348 K. The selectivity to UA was 85% at a citral conversion of 30%. These values are higher than those previously reported in the literature.