PtSn/SiO2 catalysts prepared by surface controlled reactions for the selective hydrogenation of cinnamaldehyde

Abstract

Tin-modified platinum catalysts were prepared by means of a controlled surface reaction, varying the Sn:Pt atomic ratio between 0 and 0.8. The addition of tin caused a noticeable change both in product distribution and the reaction rate. The selectivity to cinnamyl alcohol increases as a function of Sn content, reaching a value of 80% for a Sn:Pt ratio of 0.8. Reaction rate is also higher for bimetallic catalysts than for Pt/SiO2, with the highest value obtained for systems with Sn:Pt=0.2–0.4. These results are indicative of the formation of a new type of active sites, compared to those present in the monometallic catalyst. Bimetallic catalysts using a water-soluble tin precursor Bu3SnOH, were also prepared. An enhanced performance regarding the monometallic catalyst was also obtained with these materials proving to be an environmentally friendlier alternative to obtain PtSn catalysts.