Crystal facet engineering of Pt 1 /Co 3 O 4 single-atom catalysts for highly selective hydrogenation of cinnamaldehyde

The catalytic performance of single-atom Pt1/Co3O4 catalysts in the selective hydrogenation of cinnamaldehyde (CAL) is systematically investigated with a focus on crystal facet effects. Three distinct Co3O4 morphologies-cubic (Co3O4-c), truncated octahedral (Co3O4-t), and octahedral (Co3O4-o)-are synthesized to expose different facets. Among them, Pt1/Co3O4-c exhibits superior selectivity (78.1% towards cinnamyl alcohol) and conversion (97.8%) under mild conditions. Structural characterization methods combined with density functional theory (DFT) calculations reveal that the exposed (100) facets in Co3O4-c promote stronger electron transfer to Pt single atoms, enhancing the preferential hydrogenation of the CO bond over the CC bond. These findings provide valuable insights into facet-dependent electronic modulation in single-atom catalysis, facilitating the rational design of efficient catalysts for selective hydrogenation.