Engineered Nano-scale Ceramic Supports for PEM Fuel Cells. Tech Team Meeting Presentaion

Brosha, Eric L.¹  Elbaz Alon, Lior¹  Henson, Neil J.¹  Rockward, Tommy¹  Roy, Aaron²  Serov, Alexey²  Ward, Timothy² 

[1] Los Alamos National Laboratory;University of New Mexico

关键词: CARBON;    CATALYST SUPPORTS;    CATALYSTS;    CERAMICS;    COMMERCIALIZATION;    CORROSION;    DEPOSITION;    ELECTRODES;    ELECTROLYTES;    FUEL CELLS;    FUNCTIONALS;    GRAIN SIZE;    GRINDING;    HYDROGEN;    MEMBRANES;    MILLING;    OXIDES;    PLATINUM;    POLYMERS;    REDOX REACTIONS;    SURFACE AREA;    SYNTHESIS;    THERMODYNAMICS;    THIN FILMS;    X-RAY DIFFRACTION;   

DOI  :  10.2172/1048845
RP-ID  :  LA-UR-12-24079
PID  :  OSTI ID: 1048845
Others  :  TRN: US201217%%367

美国|英语

来源: SciTech Connect

【 摘 要 】

Catalyst support durability is currently a technical barrier for commercialization of polymer electrolyte membrane (PEM) fuel cells, especially for transportation applications. Degradation and corrosion of the conventional carbon supports leads to losses in active catalyst surface area and, consequently, reduced performance. As a result, the goal of this work is to develop support materials that interact strongly with Pt, yet sustain bulk-like catalytic activities with very highly dispersed particles. Ceramic materials that are prepared using conventional solid-state methods have large grain sizes and low surface areas that can only be minimally ameliorated through grinding and ball milling. Other synthesis routes to produce ceramic materials must be investigated and utilized in order to obtain desired surface areas. In this work, several different synthesis methods are being utilized to prepare electronically conductive ceramic boride, nitride, and oxide materials with high surface areas and have the potential for use as PEMFC catalyst supports. Polymer-assisted deposition (PAD) and aerosol-through plasma (A-T-P) torch are among several methods used to obtain ceramic materials with surface areas that are equal to, or exceed Vulcan XC-72R supports. Cubic Mo-based ceramic phases have been prepared with average XRD-determined crystallite sizes as low as 1.6 nm (from full profile, XRD fitting) and a BET surface area exceeding 200 m{sup 2}/g. Additionally, black, sub-stoichiometric TiO{sub 2-x}, have been prepared with an average crystallite size in the 4 nm range and surface areas exceeding 250 m{sup 2}/gr. Pt disposition using an incipient wetness approach produced materials with activity for hydrogen redox reactions and ORR. Cyclic voltammetry data will be shown for a variety of potential Pt/ceramic catalysts. Initial experiments indicate enhanced Pt metal-support interactions as well. Plane wave periodic density functional calculations (VASP) are being used to predict the thermodynamic and activation barriers for fundamental electrode processes occurring at platinum surfaces supported on thin films of the ceramic support materials. The results of this work will be used in order to optimize support properties.