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.

Solvent-free liquid phase oxidation of benzyl alcohol to benzaldehyde by molecular oxygen using non-noble transition metal containing hydrotalcite-like solid catalysts

In this paper three coordination polymers, {[Fe(fcz)2Cl2]·2CH3OH}n (1), {[Cu(fcz)2(H2O)]·SO4·DMF·2CH3OH·2H2O}n (2), and {[Cu(fcz)2Cl2]·2CH3OH}n (3) {fcz = 1-(2,4-difluorophenyl)-1,1-bis[(1H-1,2,4-triazol-l-yl)methyl]ethanol}, were synthesized. Crystallographic analysis reveals that polymer 1 exhibits a 2-D rhombohedral grid structure with (4, 4) nets, while polymer 2 has a 1-D double-chain framework. The structure of polymer 3 is similar to that of 1. We found that polymers 1–3 could effectively catalyze the oxidation of benzyl alcohol to benzaldehyde with H2O2 (30 mass-%) as oxidant in aqueous medium. Various reaction conditions were studied, and optimal reaction conditions were obtained. Under the optimal conditions, the selectivity to benzaldehyde was almost up to 100 % and the conversion of benzyl alcohol was 87 % for 1, 79 % for 2, and 68 % for 3. The results of the recycling test showed that the catalytic activity decreased by only about 7 % after three consecutive reaction cycles. However, under similar conditions, when we used the corresponding metal salt instead of the polymer as catalyst, or replaced the water with acetonitrile as solvent, neither the selectivity nor the conversion was the same. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Fe(Cu)‐Containing Coordination Polymers: Syntheses, Crystal Structures, and Applications as Benzyl Alcohol Oxidation Catalysts

Symmetrical solid oxide fuel cells (SOFCs) have attracted increasing attention due to their potential for improved thermomechanical compatibility of the electrolyte and the electrodes, reduced fabrication cost, and enhanced immunity to coking and sulfur poisoning. While the electrode materials of symmetrical SOFCs are initially limited to those with stable phase structures under both reducing and oxidizing atmospheres, many novel electrode materials are currently being developed and investigated that may undergo a beneficial phase transition or reduction in a reducing atmosphere, although the same material may be used initially for the construction of both anode and cathode. Here, the advances made in the development of electrode materials and structures for symmetrical SOFCs are summarized, including single-phase electrodes, multi-phase (composite) electrodes, and those that are reducible upon exposure to a reducing atmosphere. The electrical conductivity, thermomechanical properties, and redox behavior of these electrode materials, together with their performance and stability in different SOFCs, are discussed and analyzed. The problems associated with different types of symmetrical SOFCs are outlined and the materials that show promise as symmetrical electrodes are highlighted, offering critical insights and useful guidelines for knowledge-based rational design of better electrodes for commercially viable symmetrical SOFCs.

Progress and Prospects in Symmetrical Solid Oxide Fuel Cells with Two Identical Electrodes

Performance of Mn-Al, Co-Al, Ni-Al, Zn-Al, Mg-Fe, Mn-Fe, Co-Fe, Ni-Fe, Mn-Cr, Co-Cr, Ni-Cr, Cu-Cr, and Zn-Cr layered double hydroxides (LDH) and/or mixed hydroxides (HD) solid catalysts has been evaluated for the liquid phase oxidation of benzyl alcohol to benzaldehyde using TBHP as an oxidizing agent in the absence of any solvent The Mn, Cu, and Co containing LDH solids show good catalytic activity in the oxidation and hence these are promising catalysts for the solvent-free oxidation of benzyl alcohol to benzaldehyde

Solvent-free oxidation of benzyl alcohol to benzaldehyde by tert-butyl hydroperoxide using transition metal containing layered double hydroxides and/or mixed hydroxides

Selective oxidation and dehydrogenation of benzyl alcohol have been carried out on ABB′O3 (A=Ba, B=Pb, Ce, Ti and B′=Bi, Cu, Sb)-type perovskite oxides in the absence and in the presence of oxygen. Partial reduction of the catalyst is observed when the reaction is carried out in the absence of oxygen or at low partial pressures of oxygen. Reduced catalysts were characterised by XRD. Temperature-programmed reduction studies were carried out to determine the reducibility of the catalyst. Catalytic activity is found to depend on the reducibility of the catalysts. Copper-containing perovskites are highly reducible and BaTiO3 and BaCeO3 are the least reducible. Catalytic activity and reducibility are correlated with the metal–oxygen bonding as well as free energy of reduction of B site cations. A mechanism is proposed, which explains the ratio of benzaldehyde to toluene based on the reducibility.

Selective oxidation and dehydrogenation of benzyl alcohol on ABB′O3 (A=Ba, B=Pb, Ce, Ti and B′=Bi, Cu, Sb)-type perovskite oxides-temperature programmed reduction studies

Alkylation of toluene was carried out on microporous salts of phosphotungstic acid. Among the systems studied, M2.5H0.5PW12O40 showed maximum catalytic activity.p-Xylene selectivity was evaluated as a function of x. A linear correlation was observed betweenpara-selectivity and number of strong acid sites with strength of H0≤−5.6.

Alkylation of toluene with methanol on microporous MxH3−XPW12O40 [M=K+, Cs+, NH4 + and Tl+]

Alkylation of toluene with methanol was carried out on potassium, ammonium, cesium and thallium salts of phosphotungstic acid (M x H 3x PW 12 O 40 ; M=K + ,NH4 + ,Cs + and Tl + , x is varied from 0 to 3). The major products obtained are xylenes, tri - and tetra-methylbenzenes. The selectivity of p-xylene was found to be higher than the equilibrium values. The salts with composition M 2.5 H 0.5 PW 12 O 40 showed maximum activity and para selectivity. p-Xylene selectivity was evaluated as a function of x. It is seen that para selectivity correlates linearly with the number of strong acid sites with a strength of H o ≤5.6.

Alkylation of toluene with methanol on heteropoly compounds: p-xylene selectivity

http://nopr.niscair.res.in/bitstream/123456789/15521/1/IJCA%2038A%281%29%2040-48.pdf

Catalytic properties of BaPb 1-x Bi x O 3 perovskite oxide for partial oxidation of benzyl alcohol

The catalytic activities of BaPbl_xBix03and BaPbl_x_yBixCuy03 perovskite oxides for the gas phase oxidation of benzyl alcohol has been studied. In the absence of oxygen the major products obtained on partial oxidation of benzyl alcohol are benzaldehyde and toluene. In the presence of oxygen small amounts of benzoic acid and benzylbenzoate are also observed. Catalytic activity is found to be higher in the presence of oxygen. Catalytic activity increases with increase in Bi content in BaPbl_xBix03and Cu content in BaPbl_x_yBixCuy03. Catalysts are found to undergo reduction during the reaction.

K. Johnson

Papers

Selective oxidation and dehydrogenation of benzyl alcohol on ABB′O3 (A=Ba, B=Pb, Ce, Ti and B′=Bi, Cu, Sb)-type perovskite oxides-temperature programmed reduction studies

Alkylation of toluene with methanol on microporous MxH3−XPW12O40 [M=K+, Cs+, NH4 + and Tl+]

Alkylation of toluene with methanol on heteropoly compounds: p-xylene selectivity

Catalytic properties of BaPb 1-x Bi x O 3 perovskite oxide for partial oxidation of benzyl alcohol

Partial oxidation of benzyl alcohol on ABO 3 (A=Ba, B=Pb,Bi and Cu) type perovskite oxides