Carbon surfaces characterization

A comparison of the data in Fig. 2 (Plate A, filled circles) and Fig. 5 (Plate B, open symbols) reveals that the performance of the heat-treated wood-based carbon, even under some preloading conditions, is similar to single solute TCE uptake by coal-based activated carbons in the absence of preloading [9]. The observed effect may result from some combination of optimum surface acidity, optimal type of surface functional group, and/or pore structure effects. The WVB carbon has a mesoporous pore structure, which has been observed to minimize the impacts of preloading in preliminary comparative experiments designed to isolate this effect (data not shown). Future work will employ carbon surface characterization techniques that will allow identification of functional groups and more accurate correlation with surface reactivity. 

Bottani, E.G., Llanos, J.L., and Cascarini de Torre, L.E. (1989). Entropy determination from physisorption isotherms a useful tool for carbon surface characterization. 

Polovina, M., Babic, B., Kaluderovic, B. and Dekanski, A., Surface characterization of oxidized activated carbon cloth. Carbon, 1997, 35(8), 1047 1052. 

After reduction and surface characterization, the iron sample was moved to the reactor and brought to the reaction conditions (7 atm, 3 1 H2 C0, 540 K). Once the reactor temperature, gas flow and pressure were stabilized ( 10 min.) the catalytic activity and selectivity were monitored by on-line gas chromatography. As previously reported, the iron powder exhibited an induction period in which the catalytic activity increased with time. The catalyst reached steady state activity after approximately 4 hours on line. This induction period is believed to be the result of a competition for surface carbon between bulk carbide formation and hydrocarbon synthesis.(6,9) Steady state synthesis is reached only after the surface region of the catalyst is fully carbided. 

Molecular Characterization It has been repotted that o-qulnones oxidize ascorbic acid In homogeneous solutions (25). Surface qulnones have also been reported to exist on activated carbon surfaces (16). However, cyclic voltarammetry Is not sufficiently sensitive to allow an unambiguous Identification of the reversible wave ascribed to surface qulnones (16). Therefore, differential pulse voltammetry (DPV) and square wave voltammetry were employed. 

Specific Activity (SA) and Mass Activity (MA) of Pt Electrocatalysts Supported on Different Carbon Powders Characterized by Specific Surface Area (S) and Particle Size (d)... 

Table 12 reports the characterization of the resulting materials. In order to comment the subsequent kinetic data, XPS data were collected in order to confirm the presence of the 4f peak of metal gold at 84.0 eV and also for deriving the amount of exposed gold at the carbon surface. In Table 13 the comparison between 2 and 500 g scale preparations is reported. 

Ania CO, Bandosz TJ. Surface Chemistry of Activated Carbons and its Characterization In Activated Carbon Surfaces in Environmental Remediation, Bandosz, T J, Ed. Elsevier, Oxford, 2006.159-230. 

Xia, W. Wang, Y. Bergstrafier, R. Kundu, S. Muhler, M., Surface characterization of oxygen-functionalized multi-walled carbon nanotubes by high-resolution X-ray photoelectron spectroscopy and temperature-programmed desorption. Appt. Surface Science 2007,254 247-250. 

Donnet, J.B., Guilman, G. (1991). Surface characterization of carbon fibers. Composites 22, 59-62. 

Kalnin, I. L., and H. Jager (1985). Carbon fiber surfaces—characterization, modification and effect on the fracture behavior of carbon fiber-polymer composites, pp. 62—77. In Fitzer E., ed. Carbon Fibers and Their Composites. Springer-Verlag, New York. 

The yields obtained after 10 min in a batch reactor with MgO, CaO, or SrO exceeded 92%, whereas with BaO the yield was lower (72%), probably because of its low surface area (2m /g). When alkaline earth hydroxides were used as basic catalysts, the yields were lower than for the corresponding oxides. The most active hydroxides were Sr(OH)2 8H2O and Ba(OH)2 8H2O, which gave the additional compound in yields of 75% and 70%, respectively, whereas carbonates were characterized by very poor activity. As observed for other reactions, the catalytic activity of MgO strongly depends on the pre-treatment temperature. A maximum in activity was observed when MgO was pre-treated at 673 K. At this temperature, decomposition of Mg(OH)2 to MgO is not complete, and Mg(OH)2 remains in the catalyst. It was suggested that the surface OH groups act as active sites, as for the Michael addition reactions described above. 

The tinting strength of rubber-grade carbon blacks shows a linear relationship with D s shown in Figure 5. Since performance characteristics are known to depend on aggregate volume, surface area, and bulkiness, it appears that the D s values combine the effects of all these factors. As such, it is a valuable addition to carbon black characterization methodology. 

Yue Z.R., Jiang W., Wang L. et al. Surface Characterization of electrochemically oxidized carbon fibers. Carbon 1999 37 1785-1796. 

Despite these principal ambiguities the thermal desorption method is a standard characterization technique in carbon surface chemistry. Various examples and data about desorption profiles for a selection of carbon treatments can be found in the literature [88, 90, 155, 182, 183]. 

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