Tian Q.,Key Laboratory of Green Chemical Process of Ministry of Education |
Tian Q.,Key Laboratory of Novel Reactor and Green Chemical Technology of Hubei Province |
Tian Q.,Wuhan Institute of Technology |
Chen W.,Key Laboratory of Green Chemical Process of Ministry of Education |
And 11 more authors.
Ionics | Year: 2015
Nature clay, i.e., montmorillonite (MMT), can be used as support materials of anode electrocatalyst in the direct formic acid fuel cell. The nitrogen-containing composite support (MMT-CNx) was prepared via carbonizing MMT which was covered by polyaniline. Pd/MMT-CNx and Pd/C catalysts were prepared as formic acid oxidation catalysts using an improved liquid reduction method. The composite, structure, surface properties, and electrical conductivity of the supports and catalysts were studied by energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electrochemical impedance spectroscopy (EIS). The results showed that well-dispersed Pd nanoparticles with a narrow size distribution of 3.5–5.5 nm could be easily prepared on the MMT-CNx. Larger electrochemical specific area (ECSA) was obtained for Pd/MMT-CNx than Pd/C according to CO-stripping voltammetry. Cyclic voltammetry (CV) and chronoamperometry (CA) measurements showed better catalytic activity and stability of the Pd/MMT-CNx catalyst than the conventional Pd/C catalyst for formic acid electrooxidation. Larger ECSA and doped nitrogen in the support of the Pd/MMT-CNx catalyst may be the main reason of higher activity and better stability for formic acid oxidation compared with the Pd/C catalyst. The results offered potential application of composite support (MMT-CNx) for the catalyst of the direct formic acid fuel cell. © 2014, Springer-Verlag Berlin Heidelberg.