Selective Hydrogenation of Cinnamaldehyde to Cinnamal Alcohol over Platinum/Graphene Catalysts

Catalysts made of Pt nanoparticles dispersed on graphene (X wt %Pt/G, X=2.0, 3.5, and 5.0) were prepared and characterized by XRD, Raman spectroscopy, BET surface area measurements, TEM, and X‐ray photoelectron spectroscopy (XPS), and a 3.5 wt % Pt supported on Vulcan Carbon catalyst (3.5 wt %Pt/VC) was included as a reference. Although the mean Pt nanoparticle size is approximately 4.4 nm for all X wt %Pt/G and 3.5 wt %Pt/VC catalysts, cinnamal alcohol was produced with high selectivity only with the graphene‐supported catalysts: 92 % conversion and 88 % selectivity toward cinnamal alcohol were obtained with 3.5 wt %Pt/G. This catalyst also showed good stability in recycling tests. The good selectivity observed with the graphene‐based catalysts is attributed to the higher fraction of reduced surface Pt0 atoms seen on the surface of the Pt nanoparticles (determined by XPS). This interpretation is consistent with DFT calculations. Additional π–π interactions between cinnamaldehyde and graphene may also play a role in the selective hydrogenation of cinnamaldehyde.