Enhanced activity observed for sulfuric acid and chlorosulfuric acid functionalized carbon black as PtRu and PtSn electrocatalyst support for DMFC and DEFC applications

In this study, carbon black Vulcan XC72 was successfully functionalized in an autoclave with sulfuric acid (SA) and Chlorosulfuric acid (C-SA). The functionalized carbons were then used as supports to prepare PtRu/C and PtSn/C electrocatalysts by an alcohol-reduction process. Physical characterization was performed by BET, LS, XRD, EDX, and TEM. The electrochemical characterization showed that the catalysts supported on functionalized carbons exhibited better performance for alcohol oxidation if compared to those using unfunctionalized supports. The observed better performance can be mainly attributed to the easier access with protons (higher ionic transport), better wettability (higher water uptake), and better distribution of the nanoparticles over the support (higher platinum utilization); indicating that sulfonation is an efficient approach to functionalize, improve performance, and reduce costs of fuel cell catalysts.