Innovative carbon-free low content Pt catalyst supported on Mo-doped titanium suboxide (Ti3O5-Mo) for stable and durable oxygen reduction reaction

Recently the use of titanium oxide and titanium suboxides (Magnéli phases) has been extensively investigated as an alternative catalyst support to carbon-based materials for the oxygen reduction reaction in low-temperature fuel cells. In this study, a 15 wt.% Pt-based catalyst was developed on a unique, stable mix of titanium suboxides, with a prevailing of the Ti3O5 phase, doped with Mo, as a Ti3O5-Mo carbon-free support and compared to a commercial 20 wt.% Pt/C (E-TEK). The Pt/Ti3O5-Mo catalyst exhibits excellent electroactivity and stability toward the ORR, reaching a performance of 73.3 mA mg−1, slightly more than the double of the commercial Pt/C, with a current density of 1.1 mA cm−2 at 0.9 V vs RHE, and an half-wave potential of 0.86 V vs RHE. A deep accelerated potential cycling between 0 and 1.2 V vs RHE up to 5000 cycles demonstrated the remarkable stability of the Pt/Ti3O5-Mo catalyst, whose electrochemical surface area loss was accounted for only 11%, compared to the more than 81% loss of the commercial Pt/C reference