Preparation of Sn-modified silica-coated Pt catalysts: A new PtSn 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 CO 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.

Graphical abstractComplete separation of bifunctionality, activation of carbonyl groups and hydrogen molecules, for ultra-selective hydrogenation catalysts.Figure optionsDownload full-size imageDownload high-quality image (77 K)Download as PowerPoint slideHighlights► Tin-modified silica-coated Pt (Sn/SP) was prepared by w/o microemulsion methods. ► Role of Pt (H2 activation) and Sn (CO activation) was separated in Sn/SP. ► Sn/SP enables the highly chemo-selective hydrogenation of crotonaldehyde. ► Selectivity of crotyl alcohol attained ca. 100% with the yield of 4.1% over Sn/SP.