Preparation and electrochemical characteristics of CoTMPP-TiO2NT/BP composite electrocatalyst for oxygen reduction reaction

CoTMPP-TiO2NT/BP composites have been synthesized by preparing CoTMPP and depositing CoTMPP on carbon-supported titania nanotube (TiO2NT/BP) using microwave irradiation method at the same time, followed by heat-treatment from 300 to 900 degrees C in N-2 atmosphere. The catalytic activity for oxygen reduction was evaluated by rotating disc electrode technique in half cells with 0.5 M H2SO4. The number of electrons exchanged during ORR and the percentage of peroxide (%H2O2) produced by the reaction were evaluated for catalysts by rotating ring disk electrode (RRDE) measurements. The influences of TiO2NT doping, the heat-treating temperature and the different ratios of BP:TiO2NT on the activity of electrocatalysts for oxygen reduction were investigated. The stability of the CoTMPP-TiO2NT/BP electrocatalysts was studied with potentialstatic-polarization measurements in 0.5 M H2SO4 + 0.5 M CH3OH. CoTMPP-TiO2NT/BP composites show higher catalytic activity and better stability than CoTMPP/BP. The mechanism for the enhanced catalytic activity of CoTMPP-TiO2NT/BP is discussed. (c) 2006 Elsevier Ltd. All rights reserved.