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THE JOURNAL OF INDUSTRIAL A N D EhTGINEERING CHEMISTRY
Vol. 14,No. 9
Organic Catalysis By E. Emmet Reid JOHNS HOPKINS UNIVERSITY, BALTIMORE, MARYLAND
H E PAST year has seen much activity in the study of pressures of the hydrogen from ethyl and isopropyl alcohols the mechanism of catalysis and a more exact study of between 105' and 275' over a copper catalyst. the influence of the precise method of preparation of Matignon8 and Herzfeld consider the formation of intera catalyst on its activities, both qualitatively and quanti- mediate compounds from the standpoint of thermodynamics. tatively. The most striking contributions to the literature Dhar and Mittrag find that the oxidation of a more oxidizare briefly smmarized in-the following able substance is slowed down in the paragraphs. presence of the substance in which it induces oxidation. The second subThe mechanism of catalysis has been stance may be considered a negative catastudied by Langmuir.l Taylor and Burns2 lyst. The explanation may be found in lay a foundation for reasoning and calcu-. the formation of complexes. lating by measuring the adsorption of hydrogen, carbon monoxide, carbon dioxBurrowslO finds that the addition of ide, and ethylene by nickel, cobalt, iron, sucrose, which is itself hydrolyzed, platinum, and palladium. They find that slightly accelerates the hydrolysis of adsorption is specific and that saturamethyl acetate by hydrochloric acid. tion is reached a t low pressures. PrepSherman and co-workersll measure the arations of the metals which are good influence of amino acids, copper salts, absorbers are good catalysts. etc., on the activity of amylases. Palmer and Palmer3 make an intensive Ooffey12upsets tradition by showing study of the hydrogenation of ethylene and that, under the influence of driers, oils explain all their results in terms of the take up only 0.6 as much oxygen as without . absorption of hydrogen or ethylene on the surface of the nickel. At first the metal Taylor and study the absorption spectra of triethyl sulfonium bromide is covered with hydrogen and the reaction in eight solvents in an attempt to find a is slow. Some of this is driven off by the E. EMMET RETD connection between reactions and light heat of the reaction and ethvlene condenses on a part of the surface. This is the condition of max- absorption. Most of the absorption hands were in the calimum efficiency and the reaction slows up when too much culated positions. Baly, Heilbron, and Barker14 effect the photosynthesis of ethylene chokes up the surface. Ridea14can find no period of induction exrept when oxygen formaldehyde from carbon dioxide in water illuminated by is present. He adopts Langmuir's view that the metal is light of short wave length, X = 200 pp. The formaldehyde covered with a film of hydrogen and ethylene one molecule passes into reducing sugars in light of X = 290 pp. I n the deep and that the reaction is between the ethylene and presence of certain colored substances, the photosynthesis hydrogen molecules that find themselves adjacent in this film. takes place under the influence of visible light. h/Iaxted5 makes a quantitative study of the influence of Schwarz and Friedrich15 find that Rontgen rays poison a poisons, lead, mercury, sulfur, and zinc, on the occlusion of platinum catalyst. Rosenmund and ZetzschelGhave made an extensive study hydrogen by palladium and on the catalytic power of platinum and palladium. The rate at which hydrogen is taken of stopping reactions a t the desired place. The following up is affected far more than the amount, two weeks being reactions occur by catalytic hydrogenation: benzoyl chloride required for saturation with 19 per cent of lead on the palla- + benzaldehyde benzylalcohol * toluene. By dium. With 17 per cent of lead the amount of hydrogen adding a trace of sulfurized quinoline, 88 per cent aldehyde absorbed is reduced only 50 per cent while the rate of hydro- can be obtained. Adkins and Krause" conclude that the method of preparagenation is decreased 98 per cent, which indicates that the catalytic action is confined to the surface. To cut the tion of a catalyst is of equal, if not greater, importance than catalytic activity of platinum in half requires 10 per cent the particular metallic element present. Willstatter and Waldschmidt-Leitzl* claim that hydromercury or sulfur and only 4 per cent arsenic or zinc. Armstrong and HilditchG study the relation between the genation cannot be effected with platinum or palladium free pressure of the hydrogen and the rate of hydrogenation. from oxygen, and suggest that catalytic poisons remove this It appears that HP rather than H is the reactant, the rate all-important oxygen. Their experiments appear exact and being directly proportional to the pressure, provided at least convincing. H. S. Taylor explains their results by assuming 0.1 per cent nickel is present. With 0.01 per cent, the rate that a catalyst may so cover itself up with hydrogen that the is too low, which seems to show that a part of the metal is 8 Chim et industrie, 6 (1921), 7 , 2. phys. Chem., 98 (1921), 161. combined with the ethylene groups. 9 Chem News, 123 (1921), 313. 10 J . Chem. Soc., 119 (19211, 1798. Ridea17 makes a valuable addition to our scanty quantita11 J Am. Chem. Soc., 43 (1921), 2454, 2461, 2469. tive data on hydrogenation by determining the dissociation 12 J . Chem Soc , 121 (1922), 17.
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Trans. Faraday Soc , adv. proof 1921; C. A . , 16 (1922), 864. J . A m Chem Soc., 43 (1921), 1273. 8 Proc Roy. SOC.( L o n d o n ) , 99A (1921), 402. 4 J . Chem Soc., 121 (1922), 309. 6 Ibzd., 119 (1921), 225, 1280. 6 Proc. Roy SOC.(London), 1OOA (1921), 240. 7 I b i d , 99A (1921), 153. 1
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I b i d . , 121 (1921), 665. I b i d . , 119 (1921), 1025. 16 Ber , 55 (1922), 1040. 'erbid., 64 (I921), 428, 638, 1092, 2033, 2038; 66 (1922), 609; Abel, I b i d , 64 (1921), 1407; 65 (1922), 322. 11 J . A m Chem. Soc., 44 (1922), 385. 18 Ber., 64 (1921), 113. 18
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