Core-shell structured SiC@C supported platinum electrocatalysts for direct methanol fuel cells

Core-shell structured SiC@C with a nanoscale SiC core covered by a graphitic carbon shell was used as a novel support for Pt electrocatalyst in direct methanol fuel cells (DMFCs) to achieve high durability and catalytic performance. The SiC@C was prepared by graphitization of nano-SiC under a vacuum of 10(-3) Pa at 1500 degrees C. The epitaxial growth carbon layer had a high conductivity and an affinity for Pt catalyst metal, while SiC core retained its high stability. Pt electrocatalysts supported on SiC@C (Pt/SiC@C) were prepared using a microwave heating method. The electrochemical results showed that the Pt/SiC@C electrocatalyst had much higher catalytic activities for methanol electro-oxidation and oxygen reduction reactions than the Pt/SiC. More significantly, the Pt/SiC@C electrocatalyst showed a greater stability in comparison to the traditional Pt/C. The superior electrocatalytic performances of Pt/SiC@C were ascribed to a high dispersion of Pt nanoparticles on the SiC@C support and a high stability of the SiC@C support in acid solution. (C) 2013 Elsevier B.V. All rights reserved.