Constructing imine groups on the surface of Cu 1 /Pd(111) as a novel strategy for CO 2 hydrogenation to methanol.

Developing a promising strategy to improve the limited selectivity and activity of traditional Pd-Cu bimetallic catalysts for CO 2 hydrogenation to methanol (CH 3 OH) remains a grand challenge. By using density functional theory calculations, we discovered that introducing imine groups on the Cu 1 /Pd(111) surface through a condensation reaction of aldehydes and amines is an intriguing approach for simultaneously enhancing the selectivity and activity of Cu 1 /Pd(111) for CO 2 hydrogenation to CH 3 OH. The imine groups formed by amino reactions with acrolein on the Cu 1 /Pd(111) surface (C 3 H 4 O@NH 2 -Cu 1 /Pd(111)) improved the turnover frequency (TOF). The imine group optimized the electronic structure of active sites and increased electron transfer to the anti-bonding orbital of CO 2 , facilitating the activity of C 3 H 4 O@NH 2 -Cu 1 /Pd(111) for CO 2 hydrogenation to CH 3 OH. Besides, the inhibition of CO by-products and the low desorption energy of CH 3 OH were responsible for the high selectivity of C 3 H 4 O@NH 2 -Cu 1 /Pd(111) for CH 3 OH. This work advances our understanding of the role of imines in catalysis and provides a new strategy for designing excellent functional group-modified catalysts for the hydrogenation of CO 2 to CH 3 OH.