Oxygen, chemisorption adsorption

Considering chemisorption as chemical interaction, in our case interaction of oxygen with adsorption centers which are modeled by surface-adjacent superstoichiometric metal atoms we can write down... 

Compared to the corresponding carbides the heats of oxygen chemisorption on metals are higher. For example, on metallic tungsten the heat of adsorption is 812 kJ/mole 02, while on metallic chromium it is 730 kJ/ mole 02n. These values are significantly higher that those of the carbides of the same metals (Table 16.2). Thus, carbon atoms, when implanted in the metal lattice, reduce the adsorption affinity of the metal atoms towards oxygen. 

The SCs at the silica surface readily react with molecular oxygen. This reaction is convenient to monitor optically (Figure 7.23a). Oxygen chemisorption is accompanied by the disappearance of the optical absorption band of SCs. The adsorption of one molecule leads to the decay of one SC. Quantum-chemical calculations show that the three-member cyclic symmetric structure (Figure 7.24) is the most stable product of oxygen addition to the SC [74] ... 

The surface areas of chars prepared from cellulose samples at different HTTs were determined by application of the Dubinin-Po-lany equation to CO2 adsorption at room temperature and compared with the area occupied by surface oxides calculated from oxygen chemisorption at 230 C. The results shown in Figure 25 indicate that cellulosic chars have large surface areas that vary according to the HTT, and peak at about 550 °C. The surface oxides formed by chemisorption occupy only a portion of the total surface area, and the chemisorption also shows a peak for chars formed at about 550 °C, corresponding to the temperature of smoldering combustion. 

Stuckless JT, Wartnaby CE, Al-Sarraf N (1997) St. J. B. Dixon-Warren, M. Kovar, and D. A. King, Oxygen chemisorption and oxide film growth on Ni 100, 110, and 111 Sticking probabilities and microcalorimetric adsorption heats, J. Chem Phys 106 2012... 

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