Fluffy mesoporous AlO supported Ag-InO schottky junction catalysts for selective hydrogenation of CO of α,β-unsaturated aldehydes.

Unsaturated alcohols (UOLs) are important fine chemical intermediates. Thus, it is of great significance to design and prepare catalysts for highly selective hydrogenation of CO of α,β-unsaturated aldehydes (UALs). In this paper, a fluffy mesoporous AlO-supported Ag-InO catalyst (Ag-InO/-AlO) was synthesized by employing a two-solvent method, in which Ag and InO form a Mott-Schottky junction and lead to electron transfer from InO to Ag. Electron-rich Ag repels the CC bond owing to "four-electron repulsion", and electron-deficient InO acts as the electrophilic site to adsorb the O atom of the CO bond, thus improving the selectivity towards UOLs. In addition to a larger specific surface area and smaller mass transfer resistance, the fluffy mesopore AlO exhibits a large number of Lewis acid sites, which can further improve UOL selectivity. With the help of Ag-InO/-AlO, high UOL selectivity can be obtained from UALs containing aliphatic, aromatic and heterocyclic groups. This elaborate design of the catalyst could contribute to the highly selective hydrogenation of UALs to UOLs.