Modulation of the textures and chemical nature of C-SiC as the support of Pd for liquid phase hydrogenation

A C-SiC composite with a thin layer of carbon surrounding the SiC substrate has been produced by the reaction of SiC with CCl4. The pore structures, graphitization levels and the chemical compositions can be finely modulated by the synthesis temperature, and atmosphere. A higher synthesis temperature accelerates the chlorination rate, increases the thickness of carbon layers and enhances their graphitization. Mesopores can be generated in C-SiC composites in comparison to predominant micropores in commercial activated carbon (AC), particularly in the presence of reactive atmosphere such as CO2 and NH3. Furthermore, with cofeeding of NH3 with CCl4, N heteroatoms can be incorporated into the carbon layer and the N content varies in a range of 4.7-9.5 at.%, depending on the synthesis conditions. Both increased fraction of mesopores and their sizes, as well as N doping facilitate significantly hydrogenation of 4-carboxybenzaldehyde. The activity of Pd catalyst supported on N-doped C-SiC is five times that on commercially used AC under the same conditions.