Kinetics of Non-Platinum Group Metal Catalysts for the Oxygen Reduction Reaction in Alkaline Medium

Working in the area of alkaline fuel cell and electrolyzer technology, Acta S.p.A. developed over the past two years catalysts without Platinum Group Metals (PGM), named K14 and K18, with high activity for the oxygen reduction reaction (ORR) in alkaline medium. The comparison of the ORR activity between K14, K18 and commercial 10 wt% Pt on Vulcan XC-72R at 0.9 V vs. RHE (Reversible Hydrogen Electrode) has been carried out using Rotating Disk Electrode (RDE) analysis in 0.1 M KOH, showing how K14 has an activity close to Pt/C while the ORR activity of K18 is significantly higher. An important advantage of this catalysts is the absence of any oxidation reaction with fuels like alcohols. We used the Rotating Ring-Disk Electrode (RRDE) to detect the peroxide production and to demonstrate for K14 and, most of all, for K18 the almost complete conversion of oxygen via the 4 electrons mechanism.