Molecular sieves, addition with Subject

Nickel catalysts on a support have been and continue to be a subject of multilateral studies, the results of which have helped the development of the theory of the polyfunctional catalyst. The catalytic properties of Ni molecular sieves in the presence of H2 2, 7, 8) have not been studied completely. Study of zeolite structural changes and the condition of the metal after thermal and hydrogen treatment have been comparatively poor. The same is true for the influence of zeolite type on the catalytic activity of the metal. This study aims to give additional information on the subject. As type A molecular sieve modified with Ni proves to be a suitable subject for clarifying some of the structural and catalytic peculiarities of zeolites, it is given main consideration. 

Acetonitrile is hygroscopic and also prone to hydrolytic decomposition. Hence, in addition to water, it virtually always contains acetamide, ammonia and possibly ammonium acetate as impurities. It cannot be dried with potassium hydroxide, since this would catalyze the hydrolysis. A molecular sieve with a pore size of 0.4 nm has proved effective for the drying of acetonitrile. Following treatment with this, the solvent is subjected to fractional distillation. Application of the molecular sieve makes unnecessary the previously employed treatment with calcium hydride and phosphorus pentoxide. 

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