Effect of calcination temperature

Table 5, Effect of calcination temperature of Cera hydrate on the fired properties of p" -alumina...

Figure 5 depicts the effect of calcination temperature on subsequent catalyst activity after reduction at 300°C (572°F). Activity was measured in laboratory tubular reactors operating at 1 atm with an inlet gas composition of 0.40% CO, 25% N2, and 74.6% H2, and an inlet temperature of 300°C. Conversion of CO is measured and catalyst activity is expressed as the activity coefficient k in the first order equation ... 

Harper, F. C. (1967). Effect of calcination temperature on the properties of magnesium oxides for use in magnesium oxychloride cements. Journal of Applied Chemistry, 17, 5-10. 

Boccuzzi F, Chiorino A, Manzoli M, et al. 2001. Au/Ti02 nanosized samples A catalytic, TEM, and FTIR study of the effect of calcination temperature on the CO oxidation. J Catal 202 256-267. 

Larese, C., Lopez Granados, M., Mariscal, R. et al. (2005) The effect of calcination temperature on the oxygen storage and release properties of Ce02 and Ce—Zr—O metal oxides modified by phosphorus incorporation, Appl. Catal. B Environ., 59, 13. 

Hua, Liu, and coworkers—impact of calcination pretreatment on Au/Fe203 catalysts. Hua and coworkers524 525 reported on the effect of calcination temperature on the water-gas shift rates of Au/Fe203 catalysts prepared by co-precipitation of HAuC14 and Fe(N03)3. Calcination temperatures utilized ranged from 200 °C to 600 °C. The impact of calcination temperature on the water-gas shift rate is shown in Table 126. 

The effect of calcination temperature on the Pt dispersion for PTA on silica is clearly seen in Figure 6.23. For both methods of preparation, the dispersion is highest when the catalyst is dried at 100°C and reduced directly thereafter. At this temperature, both catalysts are white in color. As the heating/calcination temperature increases, the color first becomes light brown, and at higher temperature turns dark brown. As the calcination temperature increases, the dispersion decreases approximately linearly. Above about 500°C, the dispersion is nearly identical for both methods of preparation. 

Figure 6.30 Effect of calcination temperature (100°C or 500°C) on dispersion of Pt/y-AI203, reduced at 200°C. (From Liu, J., and Regalbuto, J.R., in preparation.)...

The effects of calcination temperature on the hydrogenolytic behaviors are shown in Fig. 4. The activity increases as the calcination temperature is increased up to 600°C. Then, the conversion is constant until the temperature reaches 750°C, whereupon it drops rapidly. The values of bja indicate almost the same tendency as the conversion. However, the degree of demeth-ylation is almost constant for all calcination temperatures and a(T/TrMeB) = 1.02, j8 = 2.8-4.7%. The increase of conversion by calcination at temperatures... 

Figure 13. Effect of Calcination Temperature 50-50 Mole% MgO-Al203.

Figure 11 Effect of calcination temperature of the V-ion-implanted titanium oxide sample on the ESR spectra of + species in the V-ion-implanted titanium oxide photocatalyst at 77 K.

The effect of calcination temperature on photocatalytic activities of HyCOM Ti02 for mineralization of acetic acid under aerated conditions50 and dehydrogenation of 2-propanol under deaerated conditions9) have also been examined and are shown in Figs. 3.8 and 3.9, respectively. 

The most obvious choice to determine phases that may be present in the molybdena catalyst is XRD. Matching of diffraction lines obtained for the catalyst with those of pure bulk compounds gives unequivocal identification of phases present. This is one of the few techniques that yields positive results. The absence of matching diffraction lines, however, is not proof that the phase in question is not present in the catalyst. The XRD technique is limited to particle sizes of above approximately 40 A for oxides or sulfides, lower sized particles giving no discernible pattern over that of the broad alumina pattern. Thus, the presence of a highly dispersed phase, either as small crystallites or as a surface compound of several layers thickness will not be detected. Also, if the phase is highly disordered (amorphous), a sharp pattern will not be obtained, although some broad structure above that of the alumina may be detected. It is a moot point as to whether such a case is considered as a separate phase or a perturbation of the alumina structure. Ratnasamy et al. (11) have examined their CoMo/Al catalyst from the latter point of view, with particular emphasis on the effect of calcination temperature. 

Gehlbach, R. E. Grindstaff, L. J. Whittaker, M. P., "Effect of Calcination Temperature on Real Density of High Sulfur Cokes," presented at 106th AIME Annual Meeting, Atlanta, Georgia, March 6-10, 1977. 

Yu, J.G., J.C. Yu, W.K. Ho and Z.T. Jiang (2002c). Effects of calcination temperature on the photo-catalytic activity and photo-induced super-hydrophilicity of mesoporous Ti02 thin films. New Journal of Chemistry, 26(5), 607-613. 

Figure 2. Effect of Calcination Temperature With Different Reductions...

Table 7. Effects of calcination temperature (7) on the total acidity (n) and the number of B acid sites ( ).

Figure 6. Effects of calcination temperature on thiophene HDS activity for two NiMo HTO catalysts without Si addition.

Reports on the thermal stabilities of faujasites and mordenites are largely confined to their resistance to collapse at elevated temperatures. There is, however, a need to extend these works to the investigations of reactions which occur during the thermal treatment of hydrogen zeolites. These include aluminum migration, dehydroxylation and formation of new active sites. The present study is concerned with the effect of calcination temperature on the crystallinity, the extent of thermal dealumination, concentration of hydroxyl groups and catalytic activity of hydrogen faujasites and mordenites with different Si/Al framework ratios. 

Figure 3. Effect of calcination temperature on cltromia/alumina atomic ratio obtained from XPS measurements.

Prica, M. et al., Effect of calcination temperature on the electrokinetic properties of colloidal zirconia, Colloids Surf. A, 119, 205. 1996. 

Table 2 shows the effect of calcination temperature on the specific surface area and the pore volume of titania. The surface area and pore volume were almost constant between 723 K and 773 K and decreased between 773 K and 823 K. 

XRD was used to study the effect of calcination temperatures on the structure of aerogels. 

The acidity of these aluminas was discussed in Chapter 4. In particular, the effect of calcination temperature on acid strength distribution is shown in Fig. 4.18. Collapse of smaller pores results in increasing pore size, as shown in Pig. 6.10. Changes in mechanical properties come from subsequent differences in, for example, plasticity or grain boundaries. These factors are important during pelleting and extrusion. 

Effect of calcination temperature on the catalytic performance of iron phosphate... 

The Effect of Calcination Temperature of Phosphotungstic Acid on Alumina on the Yield of Cyclooctene Oxide... 

Table 4.1 Effect of Calcination Temperature on Metal Dispersion in Iridium, Platinum, and Platinum-Iridium Catalysts (40,41) ...

Table I summarizes the stoichiometric composition and crystal phases determined by XRD for the different layered hydroxides immediately after synthesis. The hydroxides were calcined at temperatures between 400°C and 500°C. The effect of calcination temperature on catalytic activity is shown in Table II for the Ni-A1 hydroxide. This hydroxide was found to be most active when calcined at 450°C. Similar results were found for the other hydroxides.

In the present study Ru-Sn/Al203 catalysts were calcined in air and reduced under H2 flow at various temperatures. The effect of calcination temperature on the performance of catalysts is shown in Table 4. Calcination was performed for 4 h at the specified temperatures. After calcination the catalysts were subsequently reduced tmder the flow of H2 at 350 °C for 4 h. Results listed in Table 4 indicated that the calcination temperature hardly affected the conversion of EL, while it showed clear influence on the product selectivity. Upon increasing the calcination temperature the selectivity of ROH passed through a maximum at 350 °C. Appreciable selectivity of hydrocarbons along with conparatively lower selectivity of ROH over the catalysts, calcined at 250 °C or at a lower temperature, can be explained by a large amount of residual chlorine. On the other hand, calcination of the catalyst at 400 °C or at a higher temperature may result in the segregation of surface Ru and Sn species, and hence lower selectivity of ROL [4],... 

Figure 2 Effect of calcination temperature on TPR of Ru-Sn/Al20j catalysts. Calcination temperature (A) - 250 °C (Jt) - 400 °C (A) - 450 °C. Preparation coimpregnation, Ru loading 5 wt.%, Sn Ru atomic ratio 2.

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