Anchoring Pt Electrocatalyst with ZrO 2 on Carbon Black for Enhanced ORR Durability

Development of durable Pt-based catalysts for oxygen reduction reaction (ORR) is crucial for the commercial success of fuel cells in heavy-duty vehicle applications. Here, a facile deposition technique of ultra-thin ZrO 2 layers onto the surface of Vulcan XC72 carbon black (CB) was achieved through the condensed layer deposition technique. The follow-on deposition of Pt nanoparticles was achieved by ethylene glycol reduction of potassium tetrachloroplatinate. It was found that the Pt nanoparticles formed elongated shapes, following that of the ZrO 2 on the carbon surface, consistent with strong interfacial anchoring effect between Pt and ZrO 2 . Electrochemical tests showed that the Pt/ZrO 2 /CB catalyst has excellent electrochemical activity and durability in perchloric acids. After 10,000 cycles between 0.6 and 1.1 V RHE in 0.1 M perchloric acid, there was only ca . 10 mV loss in the half-wave potential in ORR. However, the morphology of the Pt nanoparticles changed to near spherical shapes after cycling, with a slight (1.3%) increase in the electrochemical surface area as compared to the large decrease (33.5%) in the Pt/C catalyst without ZrO 2 anchoring. It was also found that the ORR mass activity decreased by 17.8%, much better than the 37.5% decrease in Pt/C.