Unusual size effect of spinel Co0.5Fe0.5Al2O4 supported Pt catalysts on the selective hydrogenation of cinnamaldehyde

Pt/Co0.5Fe0.5Al2O4 catalysts with the average Pt particle size of 1.6-3.4 nm were prepared and applied to the selective hydrogenation of cinnamaldehyde (CAL). Not only the TOF was promoted from 0.19 to 2.70 s(-1), but also the selectivity to cinnamyl alcohol (COL) was improved from 68% to 94%, with the increase of Pt particle size. Stronger interaction occurred between Co0.5Fe0.5Al2O4 and smaller-sized Pt particles, resulting in electron-deficient Pt particles, so that C=O and C=C bond could be activated simultaneously. However, electron-rich Pt species existed on Pt/Co0.5Fe0.5Al2O4 with larger Pt size, which is beneficial for the preferential activation of C=O bond.

Automated summary

By adjusting the particle size of Pt, the TOF and selectivity of Pt/Co0.5Fe0.5Al2O4 catalysts for the selective hydrogenation of cinnamaldehyde were improved. The activation of both C=O and C=C bonds was achieved by stronger interaction between Co0.5Fe0.5Al2O4 and smaller Pt particles.