Patented June 25, 1946 2,402,684 UNITED STATES PATENT OFFICE 2,402,684 HYDROGENATION CATALYSTS AND METHODS OF PRE PARATION Frank Kerr signalgo, Wilmington, Del, assignor to E. I. du Pont de Nemours & Company, Wil mington, Del, a corporation of Delaware No Drawing. Application February 16, 1940, Serial No. 319,242 15 Claims. (C. 252-228.4) 2 This invention relates to metal sulfide catalysts Solution is added slowly an aqueous solution of for use in hydrogenation reactions and to meth Sodium polysulfide. The precipitated ferrous ods of preparing Such catalystS. m metal polysulfide is then filtered from the liquid The literature on the use of metal sulfide cat medium and washed with water to remove solu alysts for the destructive hydrogenation of car ble salts. The precipitate is protected from oxi bonaceous materials is very extensive. Such dation by the atmosphere by means of a liquid metal sulfides are prepared by a variety of meth medium such as water or organic solvents. The ods such as precipitation, decomposition of thio paste is then dried in a non-oxidizing atmos Salts, and heating metals or metal compounds phere of carbon dioxide, nitrogen, hydrogen, etc., with volatile sulfur-containing materials such as O and finally reduced in an atmosphere of hydro sulfur, hydrogen sulfide, carbon bisulfide, mer gen at a temperature of 50° to 200° C. Alter captans, etc. natively, the metal sulfide paste may be mixed The metal sulfide catalysts described in the with the material to be hydrogenated and the literature are active for the destructive hydro hydrogen treatment of the catalyst carried out genation of carbonaceous materials and desul 5 under hydrogen pressure at an elevated tem furization of petroleum and gases at high tem perature in a hydrogenation autoclave so as to gerature, as for example 300 to 600° C. These activate the catalyst in situ. The details of drastic conditions of temperature are not suit carrying out this invention will vary according able for carrying out certain desirable hydrogen to the particular ferrous metal sulfide prepared reductions of organic compounds, since extensive 20 and depending upon the type of material to be Cracking and hydrogenolysis results and mixtures hydrogenated. The following selected examples of hydrocarbons are obtained. It is therefore indicate more precisely the manner of practicing essential to the successful hydrogen reduction of this invention. The proportions of materials many organic Sulfur compounds that the catalysts used are expressed as parts by weight unless employed be active at low temperatures so that 25 Otherwise Stated. simple addition of hydrogen or cleavage by hy Eacample I drogen will occur without accompanying dis ruptive side reactions. The catalyst must of A catalyst active for the hydrogenation of sul course be immune to sulfur poisoning if sulfur fur compounds is prepared as follows: Two hun or sulfur compounds are involved. 30 dred thirty-seven parts of cobalt chloride hexa This invention has as an object the prepara hydrate was dissolved in 500 parts of water. To tion of certain new and useful sulfactive cat this was added rapidly with stirring a solution alysts. Another (bject is the preparation of a of 240 parts of sodium sulfide nonahydrate and new class of hydrcgenation catalysts. A further 64 parts of Sulfur in 900 parts of water. A black object is to prepare hydrogenation catalysts by 35 precipitate was formed which was filter and an economical and simple process. A still fur Washed with water to remove soluble salts. The , ther object is the preparation of hydrogenation precipitate was then further washed with alcohol catalysts that are active under mild conditions to free it from water. The cobalt polysulfide of temperature. Allother object is to develop cer must be protected from oxygen or air due to its tain new processes for the production of such 40 pyrophoric nature. The paste was then placed catalysts. Other objects will be apparent from in a tube fitted in an electric furnace and heated the reading of the following description of the in a stream of hydrogen. The evolution of hy invention. drogen Sulfide commenced at a temperature of These objects are accomplished by the fol 60° C. At 100° C. the evolution of hydrogen sul lowing invention which comprises treating a met 45 fide was very vigorous. As the temperature was al polysulfide, obtainabie by precipitation from slowly raised to 200° C., the evolution of hydrogen a Solution of a salt of a metal of the iron group Sulfide gradually decreased, and after 1 hour at of the periodic table, with hydrogen at a tem this temperature reduction was sufficiently com perature between 25° and 300° C. The treatment plete. This reduced catalyst must be protected with hydrogen Inay be carried out as a separate 50 from air, Since it is pyrophoric. Operation or in conjunction with the use of the The catalyst So prepared is unusually active metal sulfide as a hydrogenation catalyst. for the hydrogenation of sulfur compounds, as In practicing this invention a salt of a metal will be seen from the following example. A mix of the iron group of the periodic table is dis ture of 98 parts of cyclohexanone and 32 parts solved in water with stirring, and to the stirred 55 of Sulfur was heated in an autoclave with 9 parts y 2,402,684 3 of the catalyst described above. The autoclave 4. was charged with hydrogen at 2,000 lbs./sq. in. lbs. per sq. in. The autoclave was then heated pressure and agitated and heated to 175° C. Un to a temperature of 150 C. for 3 hours, but dure der these conditions the pressure in the autoclave ing this period there was no apparent hydrogen dropped very rapidly, and it was necessary to absorption. The temperature was raised accord add hydrogen from time to time to maintain the ingly to 170° C. and the pressure decreased only pressure in the range from 1,000 to 2,000 lbs./sq. 400 lbs. in 3 hours. No further hydrogen absorp in. The total pressure drop in three hours tion was noted. The contents of the autoclave amounted to 2,100 lbs./sq. in, after which no were then filtered to separate the catalyst and further hydrogen absorption was noted. On 0 worked up as described above. Cyclohexanethiol cooling the autoclave and filtering the product was obtained in Only 3.6% yield, indicating that from the catalyst there was obtained cyclo little reaction had occurred. hexanethiol in 74% conversion. I believe this Eacample IV type of hydrogenation reaction proceeds as An active nickel sulfide catalyst was prepared follows: 5 catalyst as follows: Ninety parts of nickel sulfate hexa (1) S -- H --> HS hydrate was dissolved in 250 parts of water and to the stirred Solution there was added a solution (2) RC=O + HS - R2C=S -- HaO of 80 parts of sodium sulfide nonahydrate and catalyst 21 parts of Sulfur dissolved in 300 parts of water. (3) RCs-S -- - RaCHS 20 The black precipitate was filtered and washed Eacample II Several times with Water to remove the soluble It will be noted that in reducing the cobalt salts. Fifteen parts of the nickel sulfide so pre polysulfide with hydrogen, as described in the pared was charged into an autoclave with 100 preceding example, the evolution of hydrogen parts of pentadecanone-8, 33 parts of sulfur, and sulfide commenced at 60° C. and was very vigor 25 50 parts of acetic acid. Hydrogen was admitted ous at 100° C. It is evident, therefore, that the to the autoclave to a pressure of 2,300 lbs./sq. in. reduction with hydrogen can conveniently be and the autoclave heated to 150° C. while being carried out under the conditions used for hy agitated. After a few minutes hydrogen was drogenation reactions. This is shown by the absorbed rapidly at this temperature but after following experiment. A solution of 237 parts of 30 One-half hour reaction became slower. The ten cobalt chloride was precipitated with a solution perature was then raised to 200° C. and further of 240 parts of sodium sulfide Saturated with absorption of hydrogen occurred until after a sulfur. The precipitate was filtered and washed total time of 2.5 hours no further absorption of with water and finally with alcohol. Ten parts hydrogen was noted. On working up the reaction of this unreduced precipitated cobalt polysulfide 35 mixture pentadecanethiol-8 was obtained in 80% was charged into a hydrogenation autoclave yield. with 98 parts of cyclohexanone and 32 parts of Eacample V sulfur. Hydrogen was admitted to the autoclave to a pressure of 2,000 lbs./sq. in and the auto Ten parts of cobalt polysulfide catalyst pre clave was heated to 150. Hydrogen was ab 40 pared as in Example II and made into a thick sorbed slowly at first while the cobalt polysul paste with acetic acid was charged into an auto fide was being reduced to the active catalyst. clave, together with 90 parts of methyl butyl After a few minutes, however, a rapid absorption ketOne and 32 parts of sulfur. Hydrogen was of hydrogen took place and more hydrogen was forced into the autoclave to a pressure of 2,000 added to maintain the pressure above 1,000 45 lbs./sq. in. and the autoclave heated to 150 C. lbs./sq. in. After 4 hours no more hydrogen was At this temperature the absorption of hydrogen absorbed, and on working up the contents of the became very rapid and additional hydrogen was autoclave cyclohexanethiol was obtained in an added to maintain the pressure in the range of amount corresponding to a conversion of 80% of 1,200-2,000 lbs./sq.