The effect of ozone oxidation on properties of commercial carbon black supported platinum (Pt) nanoparticles for the methanol electro-oxidation reaction. The results indicated that the oxygenated functional groups could be introduced on the carbon black evenly with the increase of processing time. Apparently, mainly introduced oxygenated functional group is carboxyl. Platinum nanoparticles could be uniformly immobilized on the surfaces of carbon black treated with ozone, which has significant high electro-catalytic activity and stability for methanol electro oxidation. This phenomenon is attributed to the fact that oxygen-containing groups (mainly for carboxyl functional groups) produced by ozone oxidation are good for improving the dispersion and strengthening the interaction between support and platinum nanoparticles. The ozone oxidation conditions had significant effects on the defects properties of carbon black which showed a positive correlation between the defect levels and methanol electro-oxidation performances. This paper also fully demonstrated the positive relationship between carboxyl functional groups and the performance of methanol electro catalytic oxidation.
Experimental results demonstrated that ozone oxidation increase the density of oxygenated functional groups on the commercial carbon black, especially the –COOH, which content will increase with the pretreatment time prolonging. The –COOH plays an important role in anchoring the Pt nanoparticles, which is benefit for the dispersion and size distribution of Pt nanoparticles. In addition, the poisoning resistance of catalyst enhanced through the –OH provided by oxygenated functional groups react with COads. The carbon black treated with ozone for 30 min supported Pt (Pt/C-OT-30) with the higher electro-catalytic activity for methanol oxidation.
Industrial Chemistry: Open Access