| 摘要 |
A dehydrogenation catalyst comprises predominantly (1) a synthetic calcium phosphate in which the weight ratio CaO:P2O5 is from 1,3:1 to 1,9:1 and (2) copper or iron combined with the phosphate radical, the copper or iron having been deposited by ion exchange with the phosphate and being present in an amount of from 2-20% by weight based on the calcium phosphate. Such a catalyst may be prepared by adding to an aqueous calcium hydroxide slurry a solution of phosphate at a rate such that the slurry remains alkaline and in amounts such that the CaO:P2O5 weight ratio is from 1,3:1 to 1,9:1, and thereby precipitating a basic calcium phosphate, then adding an aqueous solution of copper or iron in an amount to supply by ion exchange with the calcium phosphate, from 2-20% by weight of the metal based on the weight of the precipitated phosphate, washing and drying the product, pelletizing the product and calcining the pellets. Additionally the catalyst may contain 2-15% of a heat decomposable potassium compound, and/or at least one other metal from the group chromium, rhodium and nickel. The catalyst may be used to (1) selectively dehydrogenate cyclohexanol to cyclohexanone with suppression of phenol as a by-product, (2) dehydrogenate n-amyl alcohol to valeraldehyde, (3) dehydrogenate 4 methyl-2-pentanol to 4 methyl-2-pentanone and (4) dehydrogenate sec. butanol to methylethylketone. The potassium containing catalyst, preferably also including chromium or rhodium can be used to produce phenol from cyclohexanol, styrene from ethylbenzene and 1:3 butadiene from n-butones. Examples are given.ALSO:Dehydrogenation reactions, e.g. cyclohexanol to cyclohexanone, n-amyl alcohol to valeraldehyde, 4-methyl-2-pentanol to 4 methyl-2-pentanone and sec. butanol to methyl ethyl ketone are effected in the presence of a catalyst comprising predominantly (1) a synthetic calcium phosphate in which the weight ratio CaO:P2O5 is from 1,:1 to 1,9:1 and (2) copper or iron combined with the phosphate radical, the copper or iron having been deposited by ion exchange with the phosphate and being present in an amount of from 2-20% by weight based on the calcium phosphate. Such a catalyst, when modified by the inclusion of rhodium, may be used to dehydrogenate cyclohexanol to phenol. |
