Binary mixed oxides

Ricote, S., Jacobs, G., Milling, M., Ji, Y., Patterson, P.M., and Davis, B.H. 2006. Low temperature water-gas shift Characterization and testing of binary mixed oxides of ceria and zirconia promoted with Pt. Appl. Catal. A Gen. 303 35 47. 

Pal, B., Sharon, M. and Nogami, G. (1999). Preparation and characterization of Ti02/Fe203 binary mixed oxides and its photocatalytic properties. Mater. Chem. Phys. 59(3), 254-261. 

Figure 3 shows the differential heats of ammonia adsorption versus adsorbate coverage on sulfated binary mixed oxides. Both SZAl-2 and SZSi catalysts show similar... 

Table 5-29 Acid strength of binary mixed oxides [T41] ...

Table 16.2 NOx-sensing characteristics of capacitance sensors based on binary mixed oxides...

Using the self-formation phenomenon to fabricate hierarchically meso-mac-roporous binary mixed oxides, the mesoporosity and macroporosity can be tailored by tuning contents of the chemical components. Furthermore, the use of mixed alkoxide solutions and surfactants allows for the formation of binary metal oxide materials with structural properties of large multiporosity and high specific siuface area. Such modulable monolithic materials with multiscaled pore sizes and a wide variety of chemical compositions should be promising for multiple apphcations in catalysis and separation technology. 

In the pseudo-binary mixed-oxides the structure assumed will obviously depend on the structures of the pure oxide components, the mole ratio of these, and (most importantly) on the difference between the radii of the two cations. The first thorough study of these systems was carried out by Schneider and Roth (1960). Their specimens were prepared by solid state reaction to equilibrium of individual oxides at 1650°C or sometimes 1900°C. The phase-fields were then determined from room-temperature X-ray diffraction data, and the results correlated with the average cation radius . Full details of the observed and predicted phase relationships are best obtained from the original publication, but a general summary can be given here. 

Soylu AM, Polat M, Erdogan DA, Say Z, Yddmm C, Birer O, Ozensoy E (2014) Ti02-Al203 binary mixed oxide surfaces for photocatalytic NOx abatement. Appl Surf Sci 318 142-149... 

Physical properties of binary or ternary Ru/Ir based mixed oxides with valve metal additions is still a field which deserves further research. The complexity of this matter has been demonstrated by Triggs [49] on (Ru,Ti)Ox who has shown, using XPS and other techniques (UPS, Mossbauer, Absorption, Conductivity), that Ru in TiOz (Ti rich phase) adopts different valence states depending on the environment. Possible donors or acceptors are compensated by Ru in the respective valence state. Trivalent donors are compensated by Ru5+, pentavalent acceptors will be compensated by Ru3+ or even Ru2+. In pure TiOz ruthenium adopts the tetravalent state. The surface composition of the titanium rich phase (2% Ru) was found to be identical to the nominal composition. 

Chalcogen Binary oxides Compound Symmetry Mixed oxides Compound Symmetry... 

Cu-Mn mixed-oxide binary spinel catalysts (CuxMn3 x04, where x = 0, 0.25, 0.5, 0.75 and 1) prepared through co-precipitation method exhibit phenol methylation activity imder vapor phase conditions [75]. All of the catalysts, irrespective of the compositions, produced only C-methylated phenols. However, a total ortho selectivity of 100% with 2,6-xylenol selectivity of 74% was observed over x = 0.25 compositions at 400°C. This composition was found to be relatively stable under reaction conditions compared with the other compositions studied. The catalysts with high copper content suffered severe reduction under methylation conditions whereas, catalysts with low copper content had a hausmannite phase (Mu304) that sustained... 

To unravel a possible resonance-enhanced Raman effect in oxides with partially reduced cations, single phase, well-crystallized binary, ternary, and quaternary mixed oxides were synthesized by chemical vapor... 

---