Novel Pt-RuO2/TiO2 nanorod catalyst with enhanced activity and durability for oxygen reduction reaction

A novel Pt-RuO 2 /TiO 2 nanorod (Pt-RuO 2 /TNR) composite catalysts are prepared via the polyol method, in which the RuO 2 -TNR supports are synthesized by coprecipitation technology. Morphology characterization results demonstrate that RuO 2 nanoparticles (NPs) load on TNR carrier, and then Pt NPs uniformly disperse on the surface of RuO 2 -TNR with an average particle size of about 3.5 nm. The peak shifts of XPS patterns for Pt and Ti elements indicate the strong metal-support interaction (SMSI) between Pt NPs and RuO 2 -TNR. Compared with Pt/C catalyst, Pt-RuO 2 /TNR exhibits enhanced oxygen reduction reaction (ORR) activity and stability by the use of electrochemical testing techniques. ΔE 1/2 (about 30 mV) towards more positive potential represents the superior ORR performance of Pt-RuO 2 /TNR relative to Pt/C. Furthermore, the electrochemically active surface area (ECSA) of Pt-RuO 2 /TNR decreases only by 28 %, while the one of Pt/C is 53.8 % before and after accelerated degradation tests (ADT) for 20,000 cycles; and the loss on mass activity (MA) of the former (23 %) is much less than the one of the latter (52 %). Moreover, ECSA of Pt-RuO 2 /TNR decays only 5.8 %, whereas a considerable decline of ECSA for Pt/C is 41.5 % before and after corrosion testing for 50 h. Pt-RuO 2 /TNR could be used as an effective carbon-free electrocatalyst to improve the performance and stability of proton exchange membrane fuel cells (PEMFCs).