Phyllosilicates catalysts

Photo-oxidation reactions, 32 118 Photoreduction, metal oxides, 31 123 Phthalic acid, esterification, 17 340 Phthalocyanines EDA complexes of, 20 328-330 catalytic activity for hydrogen exchange reaction, 20 329,330 electronic configuration of, 20 330 organometallic complexes, 30 276-277 Phyllosilicates, see Layer lattice silicates, catalysts... 

Finally, when the lamellar phyllosilicate montmorillonite (homoionically exchanged with Al3 cations) is selected as catalyst, great differences in the selectivity of the reaction are observed thus when the reaction is carried out at 130°C, 3 hours, the rate of conversion is 100% and the selectivity acetanilide (2)/acetophenone (3) is 17/81, while at 160°C, 1 hour, the conversion is likewise of 100% and the rate 2/3 is 68/22. 

Reacted samples remeasured 3 months later showed that all of the reduced Fe had subsequently reoxidized to Fe(III). Previous studies have demonstrated that little clay dissolution occurs during redox cycles of phyllosilicate clays (18, 36, 44). This permits the clay to be defined as a catalyst in the truest sense. The clay facilitates the oxidation of TPB but the clay itself is not destroyed. The redox of Fe in smectites is essentially reversible (15, 38), hence the reactivity of this system is in contrast to the widely studied Fe-oxide and Mn-oxide facilitated reactions in which the oxide typically reductively dissolves and transforms during the reaction (19,20). 

Tudor, J., Willington, L., O Hare, D., and Royan, B. 1996. Intercalation of catalyticaUy active metal complexes in phyllosilicates and their application as propene p>olymerisation catalysts. Chemical Communications 2031-2032. 

The deposition-precipitation method using a base has been applied for the preparation of various catalysts. Upon raising the pH of the solution, the precipitation of a hydroxide onto the support is expected. In fact, it was shown in several cases (Table 14.2) that mixed compounds such as phyllosilicates for silica support or hydrotalcite for alumina support formed, involving support dissolution and neoformation of a mixed compound with a layered structure. 

Sivaiah, M.V., Petit, S., Beaufort, M.F., Eyidi, D., Barrault, J., Batiot-Dupeyrat, C. Valange, S. (2011) Nickel based catalysts derived from hydrothermally synthesized 1 1 and 2 1 phyllosilicates as precursors for carbon dioxide reforming of methane. Microporous and Mesoporous Materials, 140, 69-80. 

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