For carbon monoxide oxidation

Oxidation. Carbon monoxide can be oxidized without a catalyst or at a controlled rate with a catalyst (eq. 4) (26). Carbon monoxide oxidation proceeds explosively if the gases are mixed stoichiometticaHy and then ignited. Surface burning will continue at temperatures above 1173 K, but the reaction is slow below 923 K without a catalyst. HopcaUte, a mixture of manganese and copper oxides, catalyzes carbon monoxide oxidation at room temperature it was used in gas masks during World War I to destroy low levels of carbon monoxide. Catalysts prepared from platinum and palladium are particularly effective for carbon monoxide oxidation at 323 K and at space velocities of 50 to 10, 000 h . Such catalysts are used in catalytic converters on automobiles (27) (see Exhaust CONTHOL, automotive). 

Fig. 33. Reaction yield as a function of time for carbon monoxide oxidation at room temperature on pure and doped nickel oxides. NiO (200), A NiO(Li) (250), O NiO (250) X NiO(Ga) (250). Reprinted from (8) with permission. Copyright 1969 by Academic Press, Inc., New York.

Figure 1.6 Representative TEM image (a) and particle size distribution (b) obtained for a Au/Ti02 catalyst prepared by grafting of a [Au6(PPh3)6](BF4)2 complex onto Ti02 particles followed by appropriate reduction and oxidation treatments [42], The gold particles exhibit approximately spherical shapes and an average particle size of 4.7 nm.The measured Au particle sizes could be well correlated with the activity of the catalyst for carbon monoxide oxidation and acetylene hydrogenation. (Reproduced with permission from Springer.)...

Potentiometric techniques have been used to study autonomous reaction rate oscillations over catalysts and carbon monoxide oxidation on platinum has received a considerable amount of attention43,48,58 Possible explanations for reaction rate oscillations over platinum for carbon monoxide oxidation include, (i) strong dependence of activation energy or heat of adsorption on coverage, (ii) surface temperature oscillations, (iii) shift between multiple steady states due to adsorption or desorption of inert species, (iv) periodic oxidation or reduction of the surface. The work of Sales, Turner and Maple has indicated that the most... 

Activation Energies for Carbon Monoxide Oxidation on Nickel Oxide Catalysis... 

Au/Be(OH)2 catalysts are also active for carbon monoxide oxidation when the gold particles are 1 nm in size.2... 

Figure 3. Global rate constant vs. 1/ t for carbon monoxide oxidation reaction (Eq. 19).

Fia. 31. Reaction yield as a function of time for carbon monoxide oxidation at room temperature on pure and doped nickel oxides. 

Table 1 Data for carbon monoxide oxidation in a reverse-flow reactor...

Fig. 6.8. Oxidation efficiencies for carbon monoxide oxidation for Au/a-Fe203 in relation to catalyst temperature in comparison with other catalysts. (1) Au/a-Fe2 03 (Au/Fe = 1 19), prepared by CP (2) 0.5 wt% Pd/y-A Os, prepared by IMP (3) gold fine powder (4) C03O4, ex-carbonate (5) NiO (6) Au/a-Fe203 (7) 5 wt% Au/a-Fe203, prepared by IMP (8) 5 wt% AU/7-AI2O3, prepared by IMP (adapted from [183])...

Figure 10.1 shows the fitting of a rate data set for carbon monoxide oxidation to the expression ... 

The activity for carbon monoxide oxidation was plotted versus varying platinum and palladium concentration at a fixed total metals concen-... 

A similar plot depicting the effects on hydrocarbon oxidation efficiency of dilution of the catalyst concentration is presented in Figure 9. The conclusion is similar—minor variations at close to uniform distribution are not critical, and the effect is greater for aged catalyst. The effect of maldistribution on aged catalyst was greater for hydrocarbon than for carbon monoxide oxidation (cf. Figure 8). 

Figure 5. Conversion temperature as a function of space velocity for carbon monoxide oxidation with CuFe2Oh NiAl2Oh...

Quite a number of years ago we carried out some experiments on films evaporated from Alloy 99 wire. We observed that films evaporated from this wire exhibited quite different properties than those evaporated from Nickel A or Hoskins 651. The films prepared from Alloy 99 showed (211) preferential orientation and were highly resistant to sintering as measured by the hydrogen adsorption. The activity of these films for carbon monoxide oxidation was 15 times greater than the activity of films prepared from the other nickel wires. For the disproportionation of carbon monoxide, 50-60% more CO2 was found than was theoretically possible. When the wire was heated in hydrogen a large decrease in hydrogen pressure with subsequent water formation was observed. 

Matsushima, T., Ohno, Y., and Rar, A., Reaction sites for carbon monoxide oxidation on a stepped platinum (1 1 2) surface a spatial distribution study a product desorption. Surf. Sci., 293, 145-151, 1993. 

The successive loading of a ceramic carrier with tin(IV)oxide and a noble metal is an adequate method to prepare catalysts for carbon monoxide oxidation at low temperatures. 

Wicke, E., and Onken, H. U. Statistical fluctuations of conversion and temperature in an adiabatic fixed-bed reactor for carbon monoxide oxidation. Chem. Eng. Sci. 41(6), 1681-1687, 1986. 

It is very likely that an excited halogen molecule suffers induced predissociation which is the first (initial) step of the given elementary reaction. Por this reason it may be considered that the halogen atoms are the primary active centers of halogen-sensitized photochemical reactions in virtually every case. A peculiar case of photosensitization with bromine has been observed for carbon monoxide oxidation [278]. The process Brg + hv ->2Br has been found to be followed by Br + O2 + CO -> BrO + CO2, etc. 

Laine, J., Brito, J., Severino, F., Castro, G., Tacconi, P., Yunes, S., and Cruz, J. (1990) Surface copper enrichment by reduction of copper chromite catalyst employed for carbon monoxide oxidation. Catal. Lett.,... 

Frozandeh-Mehr, E., Malekzadeh, A., Ghiasi, M., Gholizadeh, A.. Mortazavi, Y., and Khodadadi, A. (2012) Effect of partial substitution of lanthanum by strontium or bismuth on structural features of the lanthanum manganite nanoparticles as a catalyst for carbon monoxide oxidation. Catal Commun., 28, il- Sl. 

A mathematical model of a wall-catalyzed reactor is used to elucidate the effects of Inlet velocity and concentration, geometry of the duct, and axial conduction on the hysteresis, multiplicity and parametric sensitivity. The monolith reactor for carbon monoxide oxidation is the prototype considered, with wall catalyst being platinum on alumina on a ceramic substrate. 

Limit cycles have recently been observed for carbon monoxide oxidation by McCarthy (6) using supported platinum on a alumina pellets and by Plichta rZ)using platiirum foil. Gradientless reactors were used in both studies, and transients in product CO2 were observed by continuous infrared analysis. 

No oscillations were observed for carbon monoxide oxidation. This may have resulted from the low turnover rates of this work which may have enabled gradientless reactor operation to be achieved with more certainty. 

Lintz and co-workers have investigated the effect of a bismuth additive in metal electrodes for carbon monoxide oxidation and have also used SEP to study carbon monoxide oxidation. ... 

---