Adsorption of Al2O3 {100} hydroxyl and Ni-Al2O3 electron transfer synergetic catalysis for efficient selective hydrogenation of unsaturated aldehydes

The hydrogenation of the C=C bond in α-β unsaturated aldehydes faces substantial difficulties due to the steric hindrance and the conjugation effects of macromolecular unsaturated aldehydes. Herein, we introduce a novel approach to prepare nanosheet-structured Ni-Al 2 O 3 catalysts featuring exposed {100} crystal planes and hydroxyl groups, utilizing a microfluidic system to easily control crystal plane growth achieve support modification. In-situ characterizations and DFT calculations reveal that the exposed {100} crystal plane, a strong metal-support interaction (SMSI) promotes electron transfer of Ni and significantly reducing the C=C hydrogenation energy barrier from 3.12   eV to 1.79   eV. The hydroxyl environment facilitates effective adsorption of the C=O bond, accelerating the reaction and enabling rapid desorption of the product. Under modified reaction conditions for the preparation of 2-ethylhexanol, the catalyst still achieved a yield of 99.9%. This simple method of support modification enables rapid large-scale preparation, possessing significant potential for industrial applications.