title: Pt-Covered Multiwall Carbon Nanotubes for Oxygen Reduction in Fuel Cell Applications.
abstract: Recently one-dimensonal (1-D) Pt nanostructures have shown greatly enhanced intrinsic oxygen reduction reaction (ORR) activity (ORR kinetic current normalized to Pt surface area) and/or improved durability relative to conventional supported Pt catalysts. In this study, we report a simple synthetic route to create Pt-covered multiwall carbon nanotubes (Pt NPs/MWNTs) as promising 1-D Pt nanostructured catalysts for ORR in proton exchange membrane fuel cells (PEMFCs). The average ORR intrinsic activity of Pt NPs/MWNTs is ∼0.95 mA/cm(2) Pt at 0.9 ViR-corrected versus reversible hydrogen electrode (RHE), ∼3-fold higher than a commercial catalyst -46 wt % Pt/C (Tanaka Kikinzoku Kogyo) in 0.1 M HClO4 at room temperature. More significantly, the mass activity of Pt NPs/MWNTs measured (∼0.48 A/mgPt at 0.9 ViR-corrected vs RHE) is higher than other 1-D nanostructured catalysts and TKK catalysts. The enhanced intrinsic activity of 1-D Pt NPs/MWNTs could be attributed to the weak chemical adsorption energy of OHads-species on the surface Pt NPs covering MWNTs.
authors: Electrochemical Energy Laboratory and Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
authors: Junhyung
authors: J
authors: Kim
authors: Electrochemical Energy Laboratory and Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
authors: Seung Woo
authors: SW
authors: Lee
authors: Electrochemical Energy Laboratory and Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
authors: Christopher
authors: C
authors: Carlton
authors: Electrochemical Energy Laboratory and Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
authors: Yang
authors: Y
authors: Shao-Horn
keywords: electrocatalysis; fuel cells; functionalized multiwall carbon nanotubes; nanostructure; oxygen reduction reaction; platinum