Influence of sulphonic acid groups on enhanced anchoring of Pt to carbon black support and hence enhanced methanol oxidation activity

Abstract

Sulphonic acid groups have been introduced on Pt supported carbon black catalyst by two different methods, i. e., (i) alkyl sulfonic acid group incorporated on the carbon black support through diazotization step by the reaction of 2-aminoethanesulfonic acid and sodium nitrite in the presence of mineral acid and (ii) methylsulfonic acid group incorporated using sodium sulphite and formaldehyde. The prepared catalysts have been characterized by FT-IR, XRD, TGA, SEM, TEM and electrochemical methods. The catalysts prepared by both the methods have shown the redistribution of Pt nanoparticles on the carbon black support upon introduction of the sulphonic acid groups, along with enhanced activity for methanol oxidation. Among these two methods of sulphonation, the latter with sodium sulphite and formaldehyde has shown better performance and stability.