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 hydrogenation to methanol (CHOH) remains a grand challenge. By using density functional theory calculations, we discovered that introducing imine groups on the Cu/Pd(111) surface through a condensation reaction of aldehydes and amines is an intriguing approach for simultaneously enhancing the selectivity and activity of Cu/Pd(111) for CO hydrogenation to CHOH. The imine groups formed by amino reactions with acrolein on the Cu/Pd(111) surface (CHO@NH-Cu/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, facilitating the activity of CHO@NH-Cu/Pd(111) for CO hydrogenation to CHOH. Besides, the inhibition of CO by-products and the low desorption energy of CHOH were responsible for the high selectivity of CHO@NH-Cu/Pd(111) for CHOH. 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 to CHOH.