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

Graphical Two kinds of electron-rich interface sites are clearly identified in ultrathin Pt/CoAl-LDH catalyst. A series of technologies found that the Pt−V O −Co δ+ interface site can change the adsorption mode of C=O bond, and the Pt−V Co −OH δ− interface site facilitates the mobility of active hydrogen. Therefore, the ultrathin catalyst exhibits enhanced COL yield under the synergistic effect of the dual interface sites. Focusing on the simultaneous enhancement of activity and selectivity in α, β-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 δ+ and Pt−V Co −OH δ− . 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 δ+ 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 δ− 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.