Tunable Selective Hydrogenation of Cinnamaldehyde by Capped Pt/Pd Nanoparticles Supported on Carbon Nanotubes

A series of catalysts containing Pt or Pd nanoparticles (NPs) jointly regulated by cytidine (Cs) and polyvinylpyrrolidone (PVP) have been prepared for selective hydrogenation of cinnamaldehyde (CAL). The Pt/Pd NPs were supported on carbon nanotubes (CNTs) with different structures for promoting catalytic activity and tuning product selectivity. The synergistic effect of Cs and PVP on Pt/Pd surface promotes hydrogenation activity. The synergy between Pd NPs and multi-walled CNTs with the diameter of <8 nm greatly promoted the hydrogenation of C=C bond in CAL. The synergy between Pt NPs and single-walled CNTs with the diameter of <2 nm effectively enhanced the hydrogenation of C=O bond in CAL. These synergistic effects are attributed to the suitable size and exposed (111) facets of metal NPs, the transfer of electrons and the interaction between metal and support.