Three-dimensional cubic ordered mesoporous carbon (CMK-8) as highly efficient stable Pd electro-catalyst support for formic acid oxidation
Nassr, Abu Bakr A.
Alaje, T. O.
Date of Issue2012
School of Chemical and Biomedical Engineering
In this work, Pd nanoparticles were supported on two types of three-dimensional cubic highly ordered mesoporous carbon (CMK-8) by the sodium borohydride reduction method and the activity of the Pd/CMK-8 electro-catalysts towards formic acid oxidation was evaluated and compared with that of commercial Pd/C (E-TEK) catalyst. The catalysts were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), cyclic voltammetry, and chronoamperometry. Cyclic voltammetry revealed Pd/CMK-8 with larger pores as being the most electroactive with a mass specific activity (mA mgPd−1) of 486.4 that exceeded not only that of the Pd/C (E-TEK) (386.5 mA mgPd−1) but also that of recently reported Pd/CNT (200 mA mgPd−1), Pd/Graphene (210 mA mgPd−1) and Pd/Vulcan XC 72 (193 mA mgPd−1). As demonstrated with chronoamperometry, the larger pore Pd/CMK-8 also proved to be the most stable catalyst. This exceptional performance can be ascribed to the very high surface area and Ia3d symmetry that yields a relatively isotropic graphitized structure with a high conductivity. In addition, the open framework of the 3-D bicontinous channels and highly ordered mesopores allows for an advanced mass transfer characteristics. The results show that CMK-8 support would significantly improve the power output and stability of Pd-based electro-catalysts for formic acid oxidation.
Journal of power sources
© 2012 Elsevier B.V.