Study of sulphonic acid functionalization of Vulcan XC-72 carbon black support of Pt/Vulcan XC-72 catalyst for methanol electrooxidation

Sulphonic acid groups have been grafted onto the surface of Vulcan XC-72 carbon of the Pt/Vulcan XC-72 catalyst to improve platinum utilization in methanol electrooxidation studies. The sulphonic acid modification has been carried out by reacting the Pt/Vulcan XC-72 catalyst with formaldehyde and sodium sulfite. The resultant sulphonated catalysts are characterized by X-ray diffraction, Fourier transform infrared spectroscopy and cyclic voltammetry. FT-IR spectra confirm the incorporation of the sulphonic acid group on the carbon black support of the catalyst. XRD shows better dispersion of the Pt nanoparticles upon sulphonic acid modification. The electrochemical measurement using cyclic voltammetry shows enhanced activity for methanol electrooxidation for the sulphonic acid modified catalyst as compared to the unmodified one.