Preparation Of Graphene Noble Metal Catalysts And Catalytic Selective Hydrogenation Of Cinnamic Aldehyde

Graphene (G) has been extensively studied in the field of chemistry, because of itsunique physical properties and chemical stability. Pt, with typical properties of catalytichydrogenation, exhibit high activity and selectivity for α, β-unsaturated carbonylcompounds selective hydrogenation. In this thesis, supported Pt-based catalystssynthesized with G and comparison carbon supports, with the cinnamaldehydehydrogenation as a model reaction, were used to study the influence of supports and Ptspecies.VC-XC72, RGO@SiO2, CNTs, G and WC/G were selected as supports,respectively. Pt-based catalysts loaded on different supports above were synthesized.BET, XRD, SEM, TEM, Raman, XPS and TG-DTA characterization were employed toanalyze the structure or the chemical and physical properties of catalysts. Bycomparison with other carbon supports, graphene exhibit a high degree of graphitization,and the contents of Pt0and PtⅡare55.9%and33.6%, respectively. Comparing withother carbon supported Pt based catalysts,3.5wt%Pt/G exhibit higher COL selectivity(87.9%) when the conversion reach92.0%. This is closely related to high mass transferefficiency, fewer surface defects, π-π interaction with CAL, suitable electron density ofgraphenes. After4recycles, the catalyst remains quite higher activity and selectivity,whose physical and chemical properties did not change significantly.The effect of reaction conditions on the catalytic performance was studiedsystematically in this thesis. When the solvent and reaction pressure were selected asisopropanol and10bar, the selectivitycan be improvedr. The higher reaction temperaturecould lead to plenty of by-products. Likewise, the hydrogenation acivity would beinhibited with the addition of al kaline co-catalyst.