Pt nanorods oriented on Gd-doped ceria polyhedra enable superior oxygen reduction catalysis for fuel cells
Guoyu Shi, Tetsuro Tano, Donald A. Tryk, Akihiro Iiyama, Makoto Uchida, Yasufumi Kuwauchi, Akihiro Masuda, Katsuyoshi Kakinuma
Abstract
Promoting the oxygen reduction reaction (ORR) performance is an urgent need to reduce the amount of Pt catalysts in fuel cells. One of the most promising strategies is interface engineering which takes advantage of the synergistic catalytic proficiencies of double or even multiple components. Herein, we synthesized the electrocatalyst that comprises Pt nanorods atomically oriented along the (1 1 1) nanofacets of Gd-doped cerium oxide polyhedra, which was much superior to commercial Pt/C catalyst for the four-electron ORR, with a 4-fold improvement of ORR intrinsic activity than Pt/C, as well as producing much less of the undesirable two-electron ORR product H2O2. It also features a remarkable stability, with negligible activity degradation in 5000-cycle test. The exposure of Pt(1 1 1) facets and the oxygen vacancy-mediated interfacial PtCe alloying facilitate O2 adsorption and dissociation together with desorption of OHad, which can account for the exceptional ORR electrocatalytic performance.