Base exchanging capacity

In agreement with the resuhs obtained by other authors, CoM was active for SCR ofNO with CH (3,5). In 6ct, Co with 42% ofB.E.C. (Base Exchange Capacity) presented a maximumNOto Nj conversion of 31 % at 450°C (Fig. 1), the selectivity at this tenqrerature being 0.74. When the sample was reduced at 350° and 500°C a decrease ofNO conversion was observed (Table 2). 

Ensminger, L. E., and Gieseking, J. E. (1941).The adsorption of proteins by montmorillonitic clays and its effect on base exchange capacity. Soil Sci. 51,125-132. 

Magnesium aluminum silicate is stable indefinitely when stored under dry conditions. It is stable over a wide pH range, has base-exchange capacity, absorbs some organic substances, and is compatible with organic solvents. 

The base exchange capacity of most of the mineral soils is about 20 mole eq./lOO... 

Mortland and Gieseking (1952) found that all the clays that they studied exerted an inhibiting effect upon the enzymatic hydrolysis of organic phosphorus c ompounds. The effect of the clays was as follows montmorillonite > Cisne > illite > kaolinite. The inhibition of phosphatase activity corresponded closely to the base exchange capacity of the clays, and was due primarily to their effect on the enzyme and riot to adsorption of the organic phosphorus compounds by the clays. 

Various studies have been made of the base-exchanging capacity of uncalcined clays (Marshall, 17), and it was recognized that this property is dependent on pH. It has been assumed by workers in this field that at moderately low pH values the hydrogen ions occupy sites corresponding to what have been termed, weak acids. The titration curves obtained with these uncalcined clays are generally similar to those found... 

Fio. 3. Ammonium base-exchanging capacity of Houdry type S-45 (SiOz-AljOt) catalyst as a function of pH of exchange medium. 

Concurrent with the preparation of these catalysts, the following properties were measured The base exchange capacity of the gels, the loss of water and ammonia (on the ammonium-treated gels) upon calcina-... 

Fig. 15. Base-exchanging capacity and water content as a function of weight-per...

Of all nano-silicate materials, the layer silicate ATP has an ideal composition for Mg5Sig02o(OH)2(OH2)4 as a natural silicate clay mineral. The distribution of Al ions among the five available octahedral positions in a chain can be accommodated either by vacancies in the octahedral positions or by some replacement of Si by Al. It is interesting to observe that a section through the above structure parallel to 010 presents the same sequence of layers of atoms as does a section of the mont-morillonite structure parallel to c when one layer of water molecules is present. The inorganic base exchange capacity, which amounts to less... 

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