Highly stable Pt-Co bimetallic catalysts prepared by atomic layer deposition for cinnamaldehyde selective hydrogenation

Pt-Co bimetallic catalysts were deposited on γ-Al₂O₃nanoparticles by atomic layer deposition (ALD) and were used for selective hydrogenation of cinnamaldehyde (CAL) to cinnamyl alcohol (COL). High resolution transmission electron microscopy, hydrogen temperature?programmed reduction, and X-ray photoelectron spectroscopy were used to confirm the strong interaction between Pt and Co. The obtained catalysts with an optimized Pt/Co ratio achieved a COL selectivity of 81.2% with a CAL conversion of 95.2% under mild conditions (i.e., 10 bar H₂and 80 °C). During the CAL hydrogenation, the addition of Co on Pt species significantly improved the activity and selectivity due to the synergetic effects of Pt-Co bimetallic catalysts, since the transfer of electrons from Co to Pt can stabilize the carbonyl groups. The obtained Pt-Co bimetallic catalysts also showed excellent stability due to the strong interaction between the metal nanoparticles and the alumina support. Negligible activity and selectivity loss was observed during the recycling experiments, showing the potential for practical applications.