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.

The increase in atmospheric carbon dioxide is linked to climate changes; hence there is an urgent need to reduce the accumulation of CO2 in the atmosphere. The utilization of CO2 as a raw material in the synthesis of chemicals and liquid energy carriers offers a way to mitigate the increasing CO2 buildup. This review covers six important CO2 transformations namely: chemical transformations, photochemical reductions, chemical and electrochemical reductions, biological conversions, reforming and inorganic transformations. Furthermore, the vast research area of carbon capture and storage is reviewed briefly. This review is intended as an introduction to CO2, its synthetic reactions and their possible role in future CO2 mitigation schemes that has to match the scale of man-made CO2 in the atmosphere, which rapidly approaches 1 teraton.

The teraton challenge. A review of fixation and transformation of carbon dioxide

Fuel processing for low-temperature and high-temperature fuel cells: Challenges, and opportunities for sustainable development in the 21st century

CATALYTIC CONVERSION OF METHANE TO MORE USEFUL CHEMICALS AND FUELS: A CHALLENGE FOR THE 21st CENTURY

Hydrogen production reactions from carbon feedstocks: fossil fuels and biomass.

Partial oxidation of methane to carbon monoxide and hydrogen over a Ni/Al2O3 catalyst

Although numerous metal oxides catalyze the oxidative dimerization of methane to higher hydrocarbons, the nature of the catalytically active sites is substantially unknown. Previous speculation that peroxide or superoxide ions are responsible for methane activation over Sm/sub 2/O/sub 3/ and over Na/sup +//MgO at high temperatures is supported by the fact that several simple peroxides, e.g., Na/sub 2/O/sub 2/, SrO/sub 2/, and BaO/sub 2/m can stoichiometrically oxidize methane. Here the authors shows, for the first time, the existence of peroxide ions on a complex metal oxide surface that catalyzes the oxidation of methane to C/sub 2/ hydrocarbons. They suggest that these peroxides may exist in a novel, through-bond isomer similar electronically to ozone.

Catalytic partial oxidation of methane over barium metaplumbate BaPbO3: possible involvement of peroxide ion

Catalytic partial oxidation of methane over Ba-Pb, Ba-Bi, and Ba-Sn Perovskites

Structure and reactivity in gas phase group five clusters. Nonreactive niobium clusters may have smooth surfaces

Partial oxidation of methane occurs in the temperature range 450–900°C by reaction of an oxygen-deficient CH 4 /O 2 mixture over a 25 wt% Ni/Al 2 O 3 catalyst. Carbon monoxide selectivities approaching 95% and virtually complete conversion of the methane feed can be achieved at temperatures >700°C. The oxidation state and phase composition of the catalyst were characterized using X-ray photoelectron spectroscopy and X-ray powder diffractometry. This study revealed that, under operating conditions, the previously calcined catalyst bed consists of three different regions. The first of these, contacting the initial CH 4 /O 2 /He feed mixture, is NiAl 2 O 4 , which has only moderate activity for complete oxidation of methane to CO 2 and H 2 O. The second region is NiO + Al 2 O 3 , over which complete oxidation of methane to CO 2 occurs, resulting in an exotherm in this section of the bed. As a result of complete consumption of O 2 in the second region, the third portion of the catalyst bed consists of a reduced Ni/Al 2 O 3 phase. Formation of the CO and H 2 products, corresponding to thermodynamic equilibrium at the catalyst bed temperature, occurs in this final region, via reforming reactions of CH 4 with the CO 2 and H 2 O produced during the complete oxidation reaction over the NiO/Al 2 O 3 phase.

Karl C.C. Kharas

Papers

Partial oxidation of methane to carbon monoxide and hydrogen over a Ni/Al2O3 catalyst

Catalytic partial oxidation of methane over barium metaplumbate BaPbO3: possible involvement of peroxide ion

Catalytic partial oxidation of methane over Ba-Pb, Ba-Bi, and Ba-Sn Perovskites

Structure and reactivity in gas phase group five clusters. Nonreactive niobium clusters may have smooth surfaces

Partial Oxidation of Methane to Carbon Monoxide and Hydrogen Over a Ni/ Al2O3 Catalyst.