Stability and durability under potential cycling of Pt/C catalyst with new surface-functionalized carbon support

• New catalyst with functionalized support shows high methanol oxidation electroactivity.
• Active area is higher than for equivalent load commercial catalyst, after acid ageing.
• New catalyst is resistant to agglomeration/dissolution when contaminated with chloride.
• New catalyst is resilient to active area loss by sintering and carbon corrosion.
• A Pt utilization factor up to 76% was estimated vs. 44% for the commercial catalyst.

In this work Pt was deposited on 4-aminobenzenesulphonic acid-functionalized carbon in order to influence the dispersion of platinum catalyst nanoparticles and decrease the resistance of three phase boundaries, for fuel cell utilization. The stability of both Pt nanoparticles and carbon supports, key issues affecting the overall performance of fuel cell catalysts, is demonstrated. The electrochemical behaviour of the new supported catalyst in a 0.5 M H2SO4 solution revealed stable voltammograms with well defined features and easy activation with just a few cycles. Tolerance to methanol was evident with the display of higher currents for electrooxidation and slow decay through 4000 cycles when compared to a commercial catalyst with the same metal loading. The effect of chloride ions and carbon corrosion on the stability of the catalyst was assessed by voltammetry, ECSA (electrochemical active surface area) values and analysis of the TEM particle size distribution after exposure. Excellent results for the own synthesized new catalyst were obtained.