Effect of particle size on selective hydrogenation of cinnamaldehyde by Pt encapsulated in mesoporous silica

Pt nanoparticles of various sizes, viz. 8, 4.9, 3.6 and 1.8 nm were encapsulated in 2D hexagonal mesoporous silica by in-situ synthesis as well as post synthetic modifications so that the final catalyst composition was ≤ 1 wt.% Pt/SiO2. A kinetic analysis of the effect of particle size on selective hydrogenation of cinnamaldehyde was carried out on these catalysts. It was found that the materials, even at such low loading of Pt, were very active for the hydrogenation and selective for the desired product, cinnamyl alcohol. Among the different particle sizes, selectivity was found to be the highest on 8 nm particles. Kinetic analysis shows that the reaction follows a consecutive reaction pathway.

Figure optionsDownload as PowerPoint slideHighlights
► Pt nanoparticles of varying sizes isolated exclusively inside channels of mesoporous silica.
► Cinnamaldehyde hydrogenation studied in catalysts with 1.8, 3.6, 4.9 and 8 nm Pt particles.
► Phenylpropanol formation more sensitive to particle size compared to that of other products.