Carlo Erba Sorpty

The total surface area of the catalyst was determined using a Carlo Erba Sorpty 1750 by applying BET method. The pores volume and size distribution were established with a Sorptomatic instrument 1900 Carl Erba, using the nitrogen desorption isotherm of the sample, assuming cylindrical pores and physical adsorption of the gas (theory of Wheeler). 

The specific surface area of the freeze-dried samples of La-montmori1 Ionite, La-Ni-rnontmori1 Ionite as well as the original Na-montmori1 Ionite were measured by the one-point-method in a Carlo Erba-Sorpty 1750 system by N2 adsorption at -196°C. The results are summarized in Table 1, It can be seen that the surface area of Na-montmori1 Ionite increases substantially upon pillaring with La from 17.1 m. g-l to 35.4 m. g" . On the... 

Catalyst surface areas were measured using the multi-point BET method on a Carlo-Erba Ins. Sorpty 1750. Before the measurements, the samples were heated under dynamic vacuum at 573 K for 1 h in order to remove adsorbed water and impurities. Measurements were made at liquid nitrogen temperature with nitrogen as the adsorbate gas. Powder X-ray diffraction measurements were performed on a Siemens Model D-500 diffractometer with Co Kc monochromatic radiation (X = 1.78901 A) and the high resolution electron microscopy was carried out on a Topcon EM-002B microscope. To prevent artefacts no solvents were used in the preparation and mounting of samples for HRTEM. 

OMNISORP Series, Beckman Coulter, USA ASAP 2400 , Flo wSorb 2300 , Micromeritics Autosorb-1 , nova 1000 , Quantachrome, USA Grimm 100 , Labortechnik, Germany Sorpty 1750 , Sorptomatic , Carlo Erba, Italy... 

XRD patterns were recorded on a Philips PW 1710 instrument using Cu K i radiation (A. = 0.15418 A, 40 kW, 25 mA). N2 sorption experiments at 77 K were carried out with a Sorpty 1750 instrument (Carlo Erba Strumentazione) and specific surface areas (SS) calculated using the BET method (Table 1). Absorption/transmission IR spectra were run at RT on a Perkin-Elmer FT-IR 1760-X spectrophotometer equipped with a Hg-Cd-Te cryodetector. For IR analysis powders were pelletted in self-supporting discs (10-15 mg cm ), activated in vacuo at increasing temperature up to 823 K, heated in dry O2 at the same temperature and cooled down in oxygen or subsequently reduced in H2 at 623 K and outgassed at the same temperature. CO and NO (Matheson C.P.) were used as probes. 

Single point nitrogen gas adsorption (Sorpty 1750, Carlo Erba) was used to determine specific surface area of the samples. Full nitrogen adsorption-desorption isotherms at 77K were measured using a Carlo Erba 1800 after outgassing for 4h at 523K. 

Surface area and pore structure The BET specific surface areas (m g l) of the nanoparticles left for digestion at various times (0.5h, 8h, 24h and 25d) and dried thereafter at 110 C, 200 C, 300 C, 40QOC, 500°C and 700°C, were determined by the single-point method of N2 adsorption at T=77K using a Carlo Erba 1750 Sorpty apparatus. The results are shown in Figure 3. 

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