[Synthesis, characterization and electrocatalytic performance of Pd/CMK-3 for formic acid oxidation]

The synthesis of mesoporous carbons CMK-3 was implemented using SBA-15 samples as the hard templates and sucrose as the carbon source. Ordered mesoporous carbon CMK-3 supported palladium catalyst with a loading amount of 20% (Pd/CMK-3) was prepared by a complexing reduction method. XRD and TEM results showed that the p6mm hexagonal symmetric pore structures of CMK-3 were highly ordered and the Pd nanoparticles with the average size of 4. 2 nm and 4. 5 nm were well dispersed on CMK-3 and activated carbon (AC) surfaces respectively. Raman results revealed that CMK-3 presented higher graphitization and a higher electric conductivity than AC. The most probable pore size of CMK-3 was 4.5 nm, which is larger than that of AC (0.54 nm). The BET surface area of CMK-3 was 1 114 m2 x g(-1), which was also larger than that of AC(871 m2 x g(-1)). The mesoporous structure of CMK-3 was also observed. The Pd/CMK-3 catalyst exhibited more excellent initial electrocatalytic activity for formic acid oxidation than Pd/AC by cyclic voltammetry (CV). But the chronoamperometry (CA) demonstrated that the stability of the two catalysts were almost equal after 100 s polarization at 0.2 V (vs. SCE).