Preparation of Sn-modified silica-coated Pt catalysts: A new Ptsingle bondSn bimetallic model catalyst for selective hydrogenation of crotonaldehyde

Selective hydrogenation of crotonaldehyde to the corresponding unsaturated alcohol, crotyl alcohol, has been investigated over Sn-modified SiO2-coated Pt catalyst. Tin-modified SiO2-coated Pt (Sn/SP) catalyst was proposed as a new concept catalyst, in which roles of Sn (to activate the Cdouble bond; length as m-dashO group of crotonaldehyde) and Pt (to activate H2) were totally separated. TEM and EXAFS experiments for Sn/SP calcined at 823 K and reduced by H2 at 573 K confirmed that Sn species were separate by impregnated from the core Pt nanoparticles. The selectivity toward crotyl alcohol over the Sn/SP catalysts calcined at 823 K and reduced by H2 at 573 K attained 100% with 4.1% of yield. These results suggest that the reaction between the activated crotonaldehyde on SnO2 sites and H2 dissociatively adsorbed on Pt proceeds over the Sn/SP catalysts.