II. Structure of Perovskites 1982 A. Crystal Structure 1982 B. Nonstoichiometry in Perovskites 1983 1. Oxygen Nonstoichiometry 1983 2. Cation Nonstoichiometry 1984 C. Physical Properties 1985 D. Adsorption Properties 1986 1. CO and NO Adsorption 1986 2. Oxygen Adsorption 1987 E. Specific Surface and Porosity 1987 F. Thermal Stability in a Reducing Atmosphere 1989 III. Acid−Base and Redox Properties 1990 A. Acidity and Basicity 1990 B. Redox Processes 1991 1. Kinetics and Mechanisms 1992 2. Reduction−Oxidation Cycles 1993 C. Ion Mobility 1993 1. Oxygen Transport 1993 2. Cation Transport 1994 IV. Heterogeneous Catalysis 1995 A. Oxidation Reactions 1995 1. CO Oxidation 1995 2. Oxidation of Hydrocarbons 1996 B. Pollution Abatement 2001 1. NOx Decomposition 2001 2. Exhaust Treatment 2002 3. Stability 2004 C. Hydrogenation and Hydrogenolysis Reactions 2004 1. Hydrogenation of Carbon Oxides 2004 2. Hydrogenation and Hydrogenolysis Reactions 2006

Chemical structures and performance of perovskite oxides.

This article provides an up-to-date perspective on the use of anion-exchange membranes in fuel cells, electrolysers, redox flow batteries, reverse electrodialysis cells, and bioelectrochemical systems (e.g. microbial fuel cells). The aim is to highlight key concepts, misconceptions, the current state-of-the-art, technological and scientific limitations, and the future challenges (research priorities) related to the use of anion-exchange membranes in these energy technologies. All the references that the authors deemed relevant, and were available on the web by the manuscript submission date (30th April 2014), are included.

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Anion-exchange membranes in electrochemical energy systems

Progress in material selection for solid oxide fuel cell technology: A review

Spinels with the formula of AB2O4 (where A and B are metal ions) and the properties of magnetism, optics, electricity, and catalysis have taken significant roles in applications of data storage, biotechnology, electronics, laser, sensor, conversion reaction, and energy storage/conversion, which largely depend on their precise structures and compositions. In this review, various spinels with controlled preparations and their applications in oxygen reduction/evolution reaction (ORR/OER) and beyond are summarized. First, the composition and structure of spinels are introduced. Then, recent advances in the preparation of spinels with solid-, solution-, and vapor-phase methods are summarized, and new methods are particularly highlighted. The physicochemical characteristics of spinels such as their compositions, structures, morphologies, defects, and substrates have been rationally regulated through various approaches. This regulation can yield spinels with improved ORR/OER catalytic activities, which can furth...

Spinels: Controlled Preparation, Oxygen Reduction/Evolution Reaction Application, and Beyond

Magnetocaloric effect: From materials research to refrigeration devices

Characterization of Ni-Infiltrated GDC Electrodes for Solid Oxide Cell Applications

A dense composite of silver and Ce0.8Sm0.2O2−δ (Ag-CSO) was manufactured from ceramic nanoparticles coated by electroless deposition of silver. At 700 °C, a 1-mm-thick membrane of the composite delivered an excellent oxygen permeation rate from air with a value of 0.04 μmol cm–2 s–1, using argon as the sweep gas and 0.17 μmol cm–2 s–1 using hydrogen. The low sintering temperature of the CSO nanoparticles allows the use of Ag rather than Pt or Pd and reduces the amount of metal needed for electronic conductivity to just 5.6 vol %, which is lower than any value reported in the literature. Oxygen diffusivity measurements confirmed that the oxygen migration remained high in the composite, with an increase in surface exchange coefficient of three orders of magnitude over Gd-doped ceria. The ease of membrane fabrication, combined with encouraging oxygen permeation rates, demonstrate the promise of the material for high-purity oxygen separation below 700 °C.

Novel Composite Cermet for Low-Metal-Content Oxygen Separation Membranes

Metallizing porous scaffolds as an alternative fabrication method for solid oxide fuel cell anodes

In this work we study the electronic conductivity of reduced Gddoped ceria in single-crystals by impedance spectroscopy in the near-room temperature regime (25-110°C). The extent of nonstoichiometry in the “as-prepared” reduced samples is determined by thermogravimetry and the integral enthalpy of re-oxidation by differential scanning calorimetry. The results indicate that the electronic transport takes place via small polarons as in the case of pure ceria. We estimate the activation energy for the process of conduction to be 0.44 eV for Ce0.8Gd0.2O1.864 and 0.45 for Ce0.7Gd0.3O1.82 eV. We found that trapping takes place at the near room temperature regime with a considerable entropic contribution. The integral enthalpy of re-oxidation for Ce0.8Gd0.2O1.864 is 4.2 eV and for Ce0.7Gd0.3O1.82 is 3.6 eV.

Enrique Ruiz-Trejo

Papers

Characterization of Ni-Infiltrated GDC Electrodes for Solid Oxide Cell Applications

Novel Composite Cermet for Low-Metal-Content Oxygen Separation Membranes

Metallizing porous scaffolds as an alternative fabrication method for solid oxide fuel cell anodes

Electronic Transport in Single Crystals of Gd-Doped Ceria

Microstructure and electrical transport in nano-grain sized Ce0.9Gd0.1O2−δ ceramics