Pt and ni carbon nitride electrocatalysts for the oxygen reduction reaction

A new synthesis route aimed at the preparation of electrocatalysts to be used for fuel cells is described. A precursor material is prepared starting from a platinum chloride and a nickel cyanometalate complex in the presence of sucrose, which acts as an organic binder. The most critical steps for the preparation of the electrocatalysts are the thermal decomposition of the precursor, which was studied in the 400-700 degrees C temperature range, and the procedure for activating the products. The resulting materials were extensively characterized via inductively coupled plasma atomic emission spectroscopy, elemental analysis, high-resolution thermogravimetry, vibrational spectroscopy in the middle and far infrared, X-ray photoelectron spectrosopy, X-ray diffraction, scanning electron microscopy, and cyclic voltammetry. These investigations yielded information regarding the influence of the preparation conditions on the structure of the final materials and their electrocatalytic performance. The electrochemical efficiency in the oxygen reduction reaction of the proposed electrocatalysts proved to be much higher than that shown by standard materials having a similar platinum content. This synthesis route appears very promising due to the ease with which materials having the desired metal composition can be obtained and the promising electrochemical performance of the resulting electrocatalysts. (c) 2007 The Electrochemical Society.