PtRu-SiO2-TiO2/C Anode Electrocatalyst for Direct Methanol Fuel Cell

The PtRu-SiO2-TiO2/C anode electrocatalyst ( loading 10wt% PtRu ) of direct methanol fuel cell is prepared by the surface reductive deposition method, using Vulcan XC-72 carbon black coated with nanometer SiO2-TiO2 (SiO2-TiO2/C) as the isotopic carrier. The surface characteristics of nanometer SiO2-TiO2 is studied through nitrogen adsorption, which shows that it is of porous structure together with large surface area, that is benefit to enhance the activity of SiO2-TiO2 and the dispersion of PtRu nanoparticle on the carrier of SiO2-TiO2/C. X-ray diffraction( XRD ) and transmission electron microscopy( TEM ) are used to characterize the catalyst. The PtRu nanoparticle homodisperse in SiO2-TiO2/C carrier with diameter around 2.4 nm. Cyclic voltammograms and chronoamperograms are conducted to compare the electrochemical methanol oxidation activity of the PtRu-SiO2-TiO2/C catalyst with the commercial PuRu/C catalyst ( 20 wt% of PtRu ). The results show that PtRu-SiO2-TiO2/C has higher catalytic activity and anti-poisoning ability for methanol oxidation, the addition of porous SiO2-TiO2 can replace the PtRu to some extent, comparing with the commercial PuRu/C catalyst, not only the loading of PtRu has been cut down 50%, but also the electro-oxidizing activity of methanol improved. The electro-oxidizing mechanism is basically analyzed.