Identification and Insight into the Role of Ultrathin LDH-Induced Dual-Interface Sites for Selective Cinnamaldehyde Hydrogenation

Focusing on the simultaneous enhancement of activity and selectivity in alpha, beta-unsaturated aldehyde hydrogenation, we designed and prepared an ultrathin CoAl-LDH supported Pt catalyst. A series of technologies revealed the ultrathin CoAl-LDH support possesses the characteristic of dual defects, oxygen vacancy (V-O) and cobalt vacancy (V-Co). Then, two kinds of vacancy related interface sites were identified, namely Pt-V-O-Co delta+ and Pt-V-Co-OH delta-. Compared with the bulk catalyst, the ultrathin catalyst exhibits both enhanced intrinsic activity and C=O bond selectivity under the synergistic effect of the dual interface sites. Specifically, the Pt-V-O-Co delta+ interface site changes the adsorption mode of cinnamaldehyde and promotes the activation of C=O bonds, thus leading to the improved cinnamyl alcohol selectivity. The H atoms of the Pt-V-Co-OH delta- interface site participate in the hydrogenation process, which facilitates the mobility of active hydrogen and therefore promotes the intrinsic activity. More importantly, the ultrathin catalyst shows good reusability.