US1299641A - Catalyzing material. - Google Patents

Description

nzncnmn WEINTRAUIB, or NEW YORK, 1v. Y.,.ASSIGNOR mo ennnn'annnnormc COMPANY, A conronnrron or NEW YORK.

CATA LYZIN'G- MATERIAL.

No Drawing.

To all whom it may oonoern Be it known that I, EZEGHIEL WEINTRAUB,

a citizen of the United States, residing at tion.

The present invention ,comprises a new form of catalyzer, consisting of a catalyzing agent and a support, which is peculiarly.

adapted to produce-a higher speed of reaction than formerly attainable.

eretofore catalyzing metals such, for ex ample, as platinum and nickel have been deposited either on granular material or on a fibrous material such as asbestos.

I have discovered the peculiar adaptability as a catalytic support of an artificial material known as fibrox described by me in Transactions of the American Electrochemioal Society, Vol. XXVII, (1915) p. 267,

and also in Patent #1,094,352,'of April 21,

1914. Fibrox 1s a soft, compressible material, consisting of a mass of fine interlacing fibers, the mass being. usually greenish 'or' white-in color and havingan apparent density of about 0.0070 to 0.0025. The speed of reactions facilitated by cataly'zers is proportional to the surface exposed by the catalyzer. The fibers of fibrox are not only veryfine, the diameter of the fibers on the average being only about 0.0006

inch, or about the wave length ofyellow lightybut which is even of' greater importance in this combination, the fibers, unlike asbestos are originally formed separated from each other by relatively'large spaces or voids. These two factors give fibrox an enormous surface per unit volume so, that when a mass of fibrox having its fibers coated with a cata'lyzer, is traversed by .gases, the eifective catalyzer surface in contact with the gases is of a different order ofmagnitude than in any other known'catalytic support, granular or fibrous. fibersof fibrox are also adapted to catalytic reactionsbecaus they withstand high temperatures, are inert to most of .the gases and are resilient andself-sup-porting. Oxid-izing gases like oxygen will at elevated'temperatures transform the silicon oxycarbid of which the fibers consist, into silica but as this transformation is not accompanied by Specification of Letters Patent.

The

'spOnge at a temperature of about 250= C.

Patent ed Apr. 8, 1919.

Application filed March 26, 1918. Serial 10. 224,895.

change of structure the effectiveness of the materlal as a catalytic support is not impaired when thus oxidized. Such trans-' Deposition from gaseous miwtWes.Ac-

cording to one method, finely divided metal is deposited onthe surface ofifibrox fibers by the reduction of a vapor compound of the respective metal in contact with the fibers. For example, finely divided nickell carbonyl vapor in contact with fibrox, platinum may 'be deposited on the fibrox by the reduction of' carbonylplatino-chlorid and osmium deposition may be carried out by the reduction of vapors of osmium tetrachlorid with hydroge v v Fibrox strips may be placed in aeontainer of. glass, quartz or the like. The air may be preferably .withdrawn with a vacuum pump and the vapor of nickel carbonylthen isadmitted preferably at reduced pressure, say at about one-fifth atmosphere, in order to allow for theincrease in volume and'pressure when the carbonyLdecomposes; The container when thus charged is heated to about 180 C. in order to decompose the nickel carbonyl, depositing finely divided nickel-on the fibrox fibers. This treat-" ment may be repeated several times to produce a desired deposit. When a deposit of platinum is desired, the fibrox is placed in a container of glass,

quartz or other material sufficiently refrae-' tory. and a-quantity of carbonyl platinomay be deposited by the decomposition of .nic e chloridisadmitted. This material may be .formed in a chamber immediately adjacent the fibrox container .by the action of carbon monoxid and chlorin gas on platinum The platinum is deposited" by heating as above described in connection with the :depo-. sition of nickel. I

Deposition from soZutiom.When it is desired to deposit a coating of nickel upon the fibrox fibers by the solution process, nickel sulfate is dissolved in water and to the solution about tvvice the amount of sodium vhypophosphite is added which is theoretically required to reduce the nickel sulfate. The fibrox is immersed 'in this solution and the solution is heated to boiling. The resulting chemical action involves.

the formation 'of nickel hypophosphite and its subsequent reduction on continuous boiling by the excess of sodium hypophosphite to form metallic nickel. The boiling is continued for at least an hour and thereupon coated fibrox will return to its initial bulk I upon drying.

Similarly a mass of fibrox may be'placed in a solution of chlorplatinic acid and an excess .of saturated solution of ferrous sulfate is added and the solution mixture is boiled. The result is a deposition of platinum on the fibers of the fibrox which thereupon should be thoroughly Washed With distilled Water.

The fibrox catalyst may be used for the oxidation of ammonia to nitric acid, the oxidation of sulfur dioxid to form sulfur trioxid for the manufacture of sulfuric acid;

sized apparatus is desirable and thereforethe large active surface offered by fibrox for a small volume is of special advantage.

In my copending application, Serial No. 224,897, filed concurrently. herewith, claims have been made on a .process of preparing the catalyst described herein.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. A catalyst comprising. fibrox and a deposit of catalyzing material on the fibers thereof.

2. A catalyst comprising a mass of interlacing fibers of silicon oxycarbid, spatially separated from each other and a depositof catalyzing material on said fibers.

v 3. A catalyst comprising fibrox and a de posit of nickel on the fibers thereof.

In witness whereo'f, I have hereunto set my hand this 20th day of March, 1918.

- EZEGIIIEL WEIN'TRAUB.