440 (1) (2) (3) (4) (5) (6) (7) (8) (9)
V. N. IPATIEFF AND B. B . CORSON
REFERENCES ELLIS:U. S.patent 148,274 (1924). GHOSHAND BAKEHI:J. Indian Chem. SOC.6, 749 (1929). GRIFFIN:J. Am. Chem. SOC.67, 1206 (1935). IPATIEFF,CORSON,AND KURBATOV: J. Phys. Chem. 43, 589 (1939). IPATIEFF, CORSON,AND KURBATOV: J. Phys. Chem. 44, 670 (1940). JULIARD AND HERBO:Bull. soc. chim. Belg. 47, 717 (1938). MOORE, RICHTER, AND VAN ARSDEL: J. Ind. Eng. Chem. 9, 451 (1917). WHITEAND BENTON:J. Phys. Chern. 34, 1784 (1931). WInrMER: German patent 271,985 (1914).
MIXED COPPER HYDROGENATION CATALYSTS
V. K. IPATIEFF AND B. B. CORSON Research Laboratories, Universal Oil Products Company, Riverside, Illinois Received July 3, 1940 INTRODUCTION
I n previous papers (4,5, 2) it was shown that pure copper is not able to hydrogenate benzene a t ordinary pressure, but that the presence of small amounts of nickel, cobalt, and chromium oxide enable it to do so. It was also shown that copper is very susceptible to poisoning by bismuth, cadmium, lead, mercury, tin, chloride, and sulfate, and that lead can function either as a poison (in concentrations of 0.1 per cent and greater) or as a promoter (in concentrations of 0.01 per cent and smaller). This paper describes the performance of fourteen series of mixed copper catalysts. These catalysts were carefully made from “reagent” chemicals, and several compositions in each series ‘were determined by analysis, but their purities were not checked spectroscopically except in the case of the copper-chromia (5) and copper-alumina series. Evidently there are many substances which, although catalytically inactive alone, possess the property of activating copper for the hydrogenation of benzene. The mixed catalysts described in this paper gave three distinct types of activity-composition curves (figure 1). Named in the order of decreasing effectiveness, ceria, alumina, thoria, and chromia gave maximum activity (eucoactics) when present to the extent of about 5 per cent, and the activity peak in the curve was sharply defined. The second type of curve was given by mixtures of copper with manganese oxide (and perhaps uranium oxide). The curve rose sharply on the addition of 2 to 5 per cent of oxide, and remained horizontal up to 80 per cent addition of impurity, beyond which it fell to zero activity. The third
MIXED COPPER HYDROGENATION CATALYSTS
441
type of activity-composition curve was given by mixtures of copper with oxides of zinc and iron. Here again, the activity curve rose sharply with small additions of impurity, but then continued to rise gradually to a eucoactic peak at 75 per cent of zinc or iron, beyond which it fell to sero activity. Juliard (6) and Juliard and Herbo (7) recently reported similar activity-composition curves in the hydrogenation of benzene (and the dehydrogenation of cyclohexane) by promoted nickel and cobalt catalysts. Medsforth (9) studied the reduction of carbon monoxide and carbon dioxide by promoted nickel catalysts, and explained the promoting action of dehydrating catalysts by their ability to dehydrate the methyl alco-
hol complex which he assumed to be an intermediate step on the way to methane and water. In the present work we found that dehydrating catalysts, e.g., alumina and thoria, are effective activators of copper for the hydrogenation of benzene, although there is no obvious methyl alcohol or water complex to be dehydrated. Moreover, copper is also activated by certain substances which are not specific dehydrating catalysts, e.g., the oxides of chromium, iron, silicon, and zinc. Juliard and Herbo (7) also found that nickel and cobalt are activated for the hydrogenation of benzeqe by both dehydrating and dehydrogenating catalysts. Therefore, Medsforth’s explanation of promoter action is either no longer tenable or is limited to the hydrogenation of the oxides of carbon and perhaps other oxygen compounds.
442
V. N. IPATIEFF AKD B. B. CORSOK EXPERIMENTAL
The methods of preparing and testing the catalysts and of calculating the results have been previously described (4, 5). The precipitant was usually ammonium carbonate, but in some cases, as in the copper-uranium series, the precipitant was ammonium hydroxide. The copper-kieselguhr and copper-silica catalysts were prepared by precipitating basic copper carbonate in the presence of kieselguhr or fresh silica gel, respectively. In several cases, such as in the copper-zinc oxide series, part of the oxide may have been reduced to metal, owing to the catalytic effect of copper (1, 3, 8, 10, ll), and in the case of uranium and manganese oxides we have no evidence as to the actual state of oxidation of the oxides. TABLE 1 Hydrogenation of benzene over mixed copper catalysts Conditions: T , 225°C.; contact time, 180 sec.; Hz:CsHe = 7 ; atmospheric pressure WEIQXT PER CENT O? ACTIVATOR COMPOSlTION
0
CeOz... . . . . . . . . . . . . . . . . . . . . . . . . A120a.. ........................ ThOz.. . . . . . . . . . . . . . . . . . . . . . . . . CrlOs . . . . . . . . . . . . . . . . . . . . . . . . .
02 1 0 5
- -I-
o I
1
'
5
-1-
10
I
35
COa. . . . . . . . . . . . . . . . . . . . . . . . . . MnO . . . . . . . . . . . . . . . . . . . . . . . . ZnO. . . . . . . . . . . . . . . . . . . . . . . . . . 0 1 21 6 FeaOa. . . . . . . . . . . . . . . . . . . . . . . . . 0 1 1 2 SiOt. . . . . . . . . . . . . . . . . . . . . . . . . . . 0 3112 3 11 K*. . . . . . . . . . . . . . . . . . . . . . . . . 0 BeO. . . . . . . . . . . . . . . . . . . . . . . . BaCOa. . . . . . . . . . . . . . . . . . . . . . SrCOa... . . . . . . . . . . . . . . . . . . . . . . . ZrOl. . . . . . . . . . . . . . . . . . . . . . . . . .
30 37 30 26 12 15 9 7 14 12 8 8
51 38 38 32 27 19 17 9 12 15
10 46
34 35 28 27 24 20 11 10 13
16 9 15 ' 9 9~ 7 8 4
36 24 22 16 30 25 18 10 9 10
~
'
0
0
;; :: 19
~
6 3l
47
1
0 0 0 0 0
8
2
7 0
3
11
'
I
,
-
* Kieselguhr from the Johns Manville Company, specially purified t o remove iron. SUMMARY
1. A variety of activators, although catalytically inactive alone, possess the property of activating copper for the hydrogenation of benzene. 2. The activity-composition curves of mixed copper catalysts containing these activators rise abruptly with small additions of activator. The shape of the remainder of the curves (beyond 5 per cent of impurity) depends upon the activ,at,or. Sometimes the curves immediately fall beyond the 5 per cent point, sometimes they remain horizontal out to 80 per cent addition before they fall, and sometimes they gradually rise from the 5 per cent point to an activity peak a t 75 per cent of activator before they fall to zero activity a t 100 per cent of activator.
WATER RELATIONS IN PLANT CELLS
443
3. The dehydrating catalysts, alumina and thoria, are effective activators of copper for the hydrogenation of benzene; this would not be predicted from Medsforth’s explanation of promoter action. The authors express their thanks to Mr. W. J. Cerveny for much of the experimental work, and to Dr. W. C. Pierce, of the University of Chicago, for the spectroscopic analyses of the copper-chromia and copper-alumina series. REFERENCES (1) ARMSTRONG ASD HILDITCH: Proc. Roy. SOC. (London) 102, 27 (1922). (2) CORSON AND IPATIEFF: J. Phys. Chem. 46, 431 (1941). (3) DEWARAND LIEBMASN:U. S.patent 1,268,692 (1918). (4) I P A T I E FCORSOS, ~, AND KURBATOV: J. Phys. Chem. 43, 589 (1939). ( 5 ) IPATIEFF, CORSON, AND KURBATOV: J. Phys. Chem. 44, 670 (1940). (6) JPLIARD:Bull. SOC. chim. Belg. 46, 549 (1937). (7) JULIARD AND HERBO: Bull. SOC. chim. Belg. 47, 717 (1938). (8) LIEBXANN: British patent 12,981 (1913). (9) MEDSFORTH: J. Chem. SOC.123, 1152 (1923). (10) ROGERS:J. Am. Chem. SOC 49, 1432 (1927) (11) T ~ Y L OASD R STARKWEATHER: J. Am. Chem. SOC.62, 2314 (1930).
.
A THERMODYKAMIC FORMULATION O F T H E WATER RELATION3 I N AN ISOLATED LIVIKG CELL P. S. TANG
AND
J. S. WANG
The Physiological Laboratory and the DepaTtment of Physics, National Tsing Hua University, Kunming, China Received August 9, 1940
I The simple osmometer concept has been applied with advantage to studies on permeability to water in animal cells (7) and to studies on the water relations in plant cells (9). Although the concept has proved useful for the purposes mentioned, the ambiguity arising from the use of the terms “turgor pressure,” “suction pressure,” “wall pressure,” “osmotic pressure,” etc. (cf. 9) in the analysis of the water relations in plant cells indicates that the water relations of living cells may perhaps be treated with more lucidity in other ways. In this account an analysis of the movement of w a k r through an isolated living cell is made with the aid of certain relations in thermodynamics. We shall consider an isolated spherical vacuolated plant cell which has been plasmolyzed until the protoplasmic mass is detached from the cell
