Calcination temperature, effect

Lanthanum oxide(99.9%) was dissolved in 1 1 HNO, solution and mixed with equal mol of FeCNO))) and then added complexing agent and dispersant( when needed) to malm a transparent solution. This solution was kept at 60-70 C to evaporate the water, and the viscous gel was formed through sol process. Kept the gel on water bath for 3-4h and then dried at 120 C, finally calcined in air at 650 C for 4h (except the calcination temperature effect study). 

Stability. AH calcitic and dolomitic limestones are extremely stable compounds, decomposing only in fairly concentrated strong acids or at calcining temperatures of 898°C for high calcium and about 725°C for dolomitic stones at 101.3 kPa (1 atm). A very mild destabilizing effect is caused by C02-saturated water, as described in the preceding section on solubihty. Aragonite, however, is not as stable as calcite. In sustained contact with moisture,... 

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. 

Calcined [MgAl] LDH was also used to adsorb penicillin G acylase [121]. The calcined LDH phases have porous structures, large specific surface areas and abundant basic sites to bind the enzymes. The effect of varying the composition of the LDH precursor and calcination temperature on the activity of the immobilized enzyme has been reported. In this case, the percentage of immobilized proteins increases up to 88 %. 

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.

Ermakova and co-workers manipulated the Ni particle size to achieve large CF yields from methane decomposition. The Ni-based catalysts employed for the process were synthesized by impregnation of nickel oxide with a solution of the precursor of a textural promoter (silica, alumina, titanium dioxide, zirconium oxide and magnesia). The optimum particle size (10 0 nm) was obtained by varying the calcination temperature of NiO. The 90% Ni-10% silica catalyst was found to be the most effective catalyst with a total CF yield of 375 gcp/gcat- XRD studies by the same group on high loaded Ni-silica... 

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.

During the course of studying the effect of crystallite sizes, attempts were made to produce very small unsupported iron oxide powders by lowering the calcination temperature of the iron hydroxyl gel that was precipitated from iron nitrate with ammonium hydroxide. However, catalysts calcined below 300°C still contain hydroxide, and they show high selectivity in butadiene production. For this reason, two catalysts, calcined at 250°C and 300°C, respectively, were studied in more detail. 

Figure 3.5 shows the effect of calcination on the physical properties of HyCOM TiOz s. The crystallite size of anatase and the BET surface area of as-prepared sample were 11 nm and 140 m2g-1, respectively. Upon elevating the calcination temperature, the crystallite size was increased and the surface area was decreased, reflecting crystal growth and sintering of the anatase crystallites upon calcination. It should be noted that even after calcination at 973 K the sample remained in the anatase phase and had a large surface area of 34 m2g-1. The factor of adsorptivity, [Ag+]ads, was also reduced by the calcination (Fig. 3.6) and almost proportional to the BET surface area (Fig. 3.7). This shows that the density (ca-...

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. 

Fig. 9.15 Effect of H2Oz concentration on the degradation of C2HC13 over Ti02 prepared by calcining at different temperatures. Calcination temperatures, ( ) 120°C, (X) 300°C, ( ) 500 600°C, (O) 700°C, ( ) 800°C.

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