Monoxide Adsorption

At room temperature carbon monoxide is adsorbed readily while simultaneously the semiconductivity is decreased (98). Probably a covalent bond is formed between CO and the copper ions of the surface, thus immobilizing electrons for the electron transfer in the lattice. Whether the bonding of the CO molecule is caused by donating two electrons from the 

CO to a Cu2+ ion or by sharing electrons with a Cu+ ion is not known. In both cases d electrons (or d levels) would be involved. 

Carbon monoxide is also readily adsorbed in ZnO (99) and a donation of electrons to the Zn2+ ions or a sharing of electrons with Zn+ ions or Zn atoms, which may both be present in ZnO (100), might be considered. A similar bond may be formed in the chemisorption of CO on Cr203 at low temperatures (liquid-air temperature). When the adsorbed gas is desorbed in this latter case (101), and also from ZnO and Cu20, it is desorbed as such. 

If it is chemisorbed on Cr203 at room temperature, however, it is desorbed as C02 (102). Apparently a more complicated surface reaction has taken place in this case. The CO probably combines with two oxygen ions of the surface to form a C03 ion while simultaneously some metal ions are reduced to a lower valency. On the surface of Cr203 this reaction may perhaps be pictured as 

When the adsorbed gas is desorbed by heating, the surface carbonate ions decompose  

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Carbon Monoxide Adsorption on the Transition Metals R. R. Ford... 

Carbon Monoxide Adsorption on the Sulfur Modified Nl(lOO) Surface... 

Kizhakevariam N, Weaver MJ. 1994. Structure and reactivity of bimetaUic electrochemical interfaces Infrared spectroscopy studies of carbon monoxide adsorption and formic acid electrooxidation on antimony-modified Pt(lOO) and Pt(lll). Surf Sci 310 183-197. 

Atli A, Ahon M, Beccat P, BertoUni JC, Tardy B. 1994. Carbon monoxide adsorption on a PtgoFe2o(lll) single-crystal alloy. Surf Sci 302 121-125. 

KitamuraF, Takahashi M, Ito M. 1989. Carbon monoxide adsorption on platinum (111) singlecrystal electrode surface studied by infrared reflection - absorption spectroscoy. Surf Sci 223 493-508. 

Kunimatsu K, Golden WG, Seki H, Philpott MR. 1985a. Carbon monoxide adsorption on a platinum electrode studied by polarization modulated FT-IRRAS. 1. Co Adsorbed in the double-layer potential region and its oxidation in acids. Langmuir 1 245 -250. 

Gilman S. 1963. The mechanism of electrochemical oxidation of carbon monoxide and methanol on platinum. I. Carbon monoxide adsorption and desorption and simultaneous oxidation of the platinum surface at constant potential. J Phys Chem 67 1989-1905. 

Cuesta A, Lopez N, Gutierrez C. 2003. Electrolyte electroreflectance study of carbon monoxide adsorption on polycrystalline silver and gold electrodes. Electrochim Acta 48 2949-2956. Date M, Hamta M. 2001. Moisture effect on CO oxidation over Au/Ti02 catalyst. J Catal 201 221-224. 

Carbon corrosion, 300 Carbon monoxide adsorption, 248,250,255, 325-327, 347, 386-391,528-532 Carbon monoxide oxidation... 

The Pd-Sn/C catalysts (1 to 7.5% Pd containing 0 to 1% Sn) were heated under vacuum at 150°C and then exposed to hydrogen. These preactivated samples were then titrated with carbon monoxide, a veiy specific ligand for Pd, up to 800 Torr at 30°C. A general linear trend of carbon monoxide concentration with % Pd in Figure 15.3 indicates that the carbon monoxide adsorption is directly correlated to Pd concentration, as expected. The trend is independent of Sn content. This linear Pd-CO trend indicates that the particle size distribution is similar for the different catalysts. However, Figure 15.3 also indicates no relationship between % H2S irreversibly adsorbed and % Pd. 

Wesner, D. A., Linden, G., and Bonzel, H. P. 1986. Alkali promotion on cobalt Surface analysis of the effects of potassium on carbon monoxide adsorption and Fischer-Tropsch reaction. Appl. Surf. Sci. 26 335-56. 

Vibrational Spectroscopic Studies of Adsorbate Competition During Carbon Monoxide Adsorption on Platinum Electrodes... 

AljOj catalysts, metal dispersion, 39 240 -amine complexes, COj reduction, 28 142 -carbon monoxide adsorption, 28 4, 6 energy, 28 15 structure, 28 10, 14 desorption, 28 23 as catalyst... 

E. J. Walter, S. P. Lewis, and A. M. Rappe, Eirst-principles study of carbon monoxide adsorption on zirconia-supported copper. Surf. Sci. 495, 44-50 (2001). 

Kinetics of Adsorption and Desorption and the Elovich Equation C. Aharoni and F. C. Tompkins Carbon Monoxide Adsorption on the Transition Metals R. R. Ford... 

Kebulkova, L., Novakova,)., Jaeger, N.I., and Schultz-Ekloff, G. (1993) Characterization of nickel species at Ni/7-Al203 and Ni/faujasite catalysts by carbon monoxide adsorption. Appl Catal. A,... 

Fig. 19. Illustration of carbon monoxide adsorption followed by oxygen adsorption on metal oxides [W. G. Garner, J. Chem. Soc. 1239 (1947)].

In carbon monoxide the bond between the atoms depends, as in the N2O molecule, on an asymmetrical electron shift, electrons of the 0 atom moving toward the C atom, and the CO molecule having a dipole character. In this case, too, metal electrons are displaced toward the adsorbed molecule and taken from the electron gas, as shown by the change of the electrical resistance of thin nickel films on carbon monoxide adsorption (18). 

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