Crystal structures mixed oxides

The present work demonstrates that the mixed oxide catalyst with inhomogeneous nanocrystalline MosOu-type oxide with minor amount of M0O3- and Mo02-type material. Thermal treatment of the catalyst shows a better performance in the formation of the crystals and the catalytic activity. The structural analysis suggests that the catalytic performance of the MoVW- mixed oxide catalyst in the partial oxidation of methanol is related to the formation of the M05O14 t3 e mixed oxide. 

In contrast with the Schiff base salen, salicylaldehyde oxime (79) (salox) complexes of Co have received comparatively little attention, but a series of bis-bidentate divalent complexes of the form iraiis-Co(sa 1 ox)2( D M SO)2 have been reported.343 The heterocyclic bidentate oxime violurate (lH,3H-pyrimidine-2,4,5,6-tetrone 5-oximate, Hvi) (80) and its /V-methyl (mvi) and /V,/V -dimethyl (dmvi) derivatives form high-spin divalent [Co(vi)]+ and Co(vi)2 complexes, whereas [Co(vi)3] is low spin.344 The mixed-ligand Co(dmvi)2(phen) complex is also low spin. The crystal structure of m-Co(pxo)2Br2 (pxo = 2-acetylpyridine-l-oxide oxime) is isostructural with the Ni11 relative.345 The dichloro complex also adopts a cis configuration. The tridentate dioximes 2,6-diformyl-4-methylphenol dioxime and 2,6-diacetyl-4-methylphenol dioxime (Hdampo) form binuclear complexes of the type (81a) and (81b) respectively.346 Cobalt oxide nanoparticles were prepared by... 

The one-step reaction of H2prCl6] with MeC02Li under 02 in a mixed solvent of acetic acid and acetic anhydride yields the Ir11 binuclear complex [Ir2(/u-02CMe)2Cl2(C0)2].483 Crystal-structure determinations of [Ir2(/x-02CMe)2Cl2(C0)2L2], (295), where L = MeCN, DMSO, and py, are reported. The one-electron oxidation product for (295), L = py, is EPR active at 77 K the odd electron occupies the 6Ir Ir orbital. 

The crystal structures of [Ag(l,4-dioxane)]AsF69 9 and [Ag2(l,4-oxathiane)](N03)295° have been reported. Two adducts of the 4-nitropyridine A-oxide with silver nitrate have been characterized, one is a mononuclear tetracoordinated compound [Ag(N03)(0NC5H4N02)2] and the other is a dinuclear pentacoordinated species [Ag2(N03)2(/u-0NC5H4N02)2(0NC5H4N02)2] (130).951,952 In the mixed compound /nmv-[RhCl2(py)4]N03-AgN03 exists the dinitroargentate(I) ion in a distorted tetrahedral environment 953... 

Figure 4 Crystal structure of the mixed valent oxide Te2Os. The [Te(VI)Og] octahedra are linked to chains via common edges, and the chains are connected by [Te(IV)04]2 dimers.

In this part, we prepared and studied the Ag/Si02 catalyst by one-step and two-step sol-gel methods. The results show that the Ag/Si02 catalyst prepared here is one kind of bulk material which has a high surface area. The Ag/Si02 catalyst is made up with functional component of Ag or silver oxide in 20 to 30 nm and carrier Si02. Moreover, we found that the different preparation methods have great effect on crystal structure of the samples. The structure of the sample prepared by the one-step method is always a single crystal structure. And the structure of the sample prepared by the two-step method is always a mixed crystal structure. 

Zhang, RD Alamdari, H Kaliaguine, S. Crystal structure, redox properties and catalytic performance of Ga-based mixed oxides for NO reduction by CsHg, Catalysis Communications, 2008, Volume 9, 111-116. 

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