Particularly tested for carbon based substrates such as carbon nanocabon tubes, the proposed method has enabled the synthesis of platinum-cobalt nanoparticles featuring lower dimensions, narrower size distributions and higher stabilities compared to the conventional methods.
The major goal of the mentioned research work has been set as preparation of a potent Pt-based catalyst for methanol oxidation reactions occurring in the fuel cells by impregnation of the catalyst precursors upon suitably chosen substrates. During recent years, Direct Methanol Fuel Cells (DMFCs) have attracted a great deal of attention as a clean and green source of energy for various electronic devices and vehicles.
"The most innovative feature of our proposed method is the fabrication of Pt-based alloys at high temperatures in form of 3-nm-sized particles on CNT substrates such that they exhibit spectacularly high thermal stability," Dr. Rozgar Ahmadi, a member of the research group, said.
"This is due to the utilization of elemental sulfur as a modifying agent in course of the synthesis process which allows for obtaining smaller particles, better dispersions and higher degree of alloying. In the final step of synthesis, the used sulfur is totally eliminated through a thermal treatment process in order to avoid any possible catalyst poisoning," he added.
The above-mentioned synthesis technique has proved to be simple and straightforward and does not require any costly or complicated apparatus. In addition, the method seems attractive from a commercialization point of view as its scale-up is claimed smooth and trouble-free.
An elaborate scientific article discussing the research work, "Pt-Co alloy nanoparticles synthesized on sulfur-modified carbon nanotubes as electrocatalysts for methanol electrooxidation reaction", has been published in Journal of Catalysis, volume 292, 2012, pages 81-89.