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Title: In situ characterization of nanoscale catalysts during anodic redox processes

Controlling the structure and composition of the anode is critical to achieving high efficiency and good long-term performance. In addition to being a mixed electronic and ionic conductor, the ideal anode material should act as an efficient catalyst for oxidizing hydrogen, carbon monoxide and dry hydrocarbons without de-activating through either sintering or coking. It is also important to develop novel anode materials that can operate at lower temperatures to reduce costs and minimized materials failure associated with high temperature cycling. We proposed to synthesize and characterize novel anode cermets materials based on ceria doped with Pr and/or Gd together with either a Ni or Cu metallic components. Ceria is a good oxidation catalyst and is an ionic conductor at room temperature. Doping it with trivalent rare earths such as Pr or Gd retards sintering and makes it a mixed ion conductor (ionic and electronic). We have developed a fundamental scientific understanding of the behavior of the cermet material under reaction conditions by following the catalytic oxidation process at the atomic scale using a powerful Environmental Scanning Transmission Electron Microscope (ESTEM). The ESTEM allowed in situ monitoring of structural, chemical and morphological changes occurring at the cermet under conditions approximating thatmore » of typical fuel-cell operation. Density functional calculations were employed to determine the underlying mechanisms and reaction pathways during anode oxidation reactions. The dynamic behavior of nanoscale catalytic oxidation of hydrogen and methane were used to determine: ? Fundamental processes during anodic reactions in hydrogen and carbonaceous atmospheres ? Interfacial effects between metal particles and doped ceria ? Kinetics of redox reaction in the anode material« less
 [1] ;  [2] ;  [2]
  1. National Institute of Standards and Technology
  2. Arizona State University
Publication Date:
OSTI Identifier:
Report Number(s):
DOE Contract Number:
Resource Type:
Technical Report
Research Org:
Arizona State University
Sponsoring Org:
USDOE; USDOE SC Office of Basic Energy Sciences (SC-22)
Country of Publication:
United States
08 HYDROGEN; 36 MATERIALS SCIENCE Ceria, Doped ceria, Anode material, SOFC, ETEM