Controlling hydrogenation selectivity with Pd catalysts on carbon nitrides functionalized silica

We report here the synthesis of Pd nanoparticles (NPs) supported on a carbon nitrides-silica composite (S-C_T) and its application as a catalyst in the hydrogenation of 1,5-cyclooctadiene. While the mesoporous silica provides a high surface area, the carbon nitrides (CNx) stabilize the Pd NPs, and the Pd particle size can be controlled by varying the treatment temperature (T) for the composite. The Pd catalysts show good conversion and selectivity for hydrogenation both at elevated pressure (50-80 degrees C, H-2 pressure 2 MPa) and at atmospheric pressure, even at zero degrees, and the selectivity can be well controlled owing to the controlled particle size of the Pd NPs. Furthermore, after reusing the catalyst 6 times, no loss in selectivity is observed while the conversion is slightly decreased to about 15%. Thus, an active Pd catalyst with prolonged lifetime for hydrogenation is observed when carbon nitrides-silica composites are used as support. (C) 2015 Elsevier Inc. All rights reserved.