Benzene hydrogenation, temperature particles

Example 3.13.2.A Temperature Gradients inside the Gatalyst Particles in Benzene Hydrogenation... 

TEMPERATURE GRADIENTS INSIDE THE CATALYST PARTICLES IN BENZENE HYDROGENATION... 

Dry hydrogen chloride (about 5 g.) is passed into a suspension of 200 g. (1.50 moles) of anhydrous aluminum chloride in 400 g. of benzene, and then 126 g. (1.97 moles) of dry gaseous sulfur dioxide is introduced into the mixture Hood). After standing 12 hours at room temperature, the reaction mixture is poured on crushed ice and a solution of 260 g. (6.50 moles) of sodium hydroxide in 1 1. of water is added. The resulting mixture is heated on a water bath under a reflux condenser until the yellow particles of the aluminum chloride-benzenesulfinic acid salt have disappeared. The mixture is steam-distilled to remove excess benzene (about 250 g. is collected), and carbon dioxide is passed into the reaction mixture to cause precipitation of the alumina. After filtration the filtrate is evaporated and concentrated hydrochloric acid is added to the cold solution to precipitate the benzenesulfinic acid. A yield of 170 g. (80%) of pure product melting at 83° is obtained. 

PaHadiumammine complex cations exchange-adsorbed on the surface of active charcoal (AC) were decomposed under 150° in the air and then were reduced easily with hydrogen at low temperature. Palladium metal particles were dispersed very finely and homogeneously on the surface of AC and again exhibited a very high selective activity for the hydrogenation of the benzene nucleus. 

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