| 摘要 |
1,253,975. Catalysts comprising copper acetylide. E.I. DU PONT DE NEMOURS & CO. 23 Oct., 1968 [23 Oct., 1967], No. 50416/ 68. Heading B1E. [Also in Division C2] A particulate ethynylation catalyst consists solely of or comprises a cuprous acetylide complex which contains at least 1.75 atoms of carbon per atom of copper, the catalyst having a total surface area of at least 5.0 square metres per gram and at least 75 weight per cent of the particles of catalyst having a crosssectional dimension of at least 5.0 microns. It is preferred that essentially all of the particles of catalyst have at least one cross-sectional dimension greater than 3 microns and that the average particle size of the catalyst is from 10 to 20 microns. Cuprous copper preferably constitutes at least 20 weight per cent of the catalyst which preferably is substantially free of metallic copper. The cuprous acetylide complex preferably comprises copper, carbon, hydrogen and oxygen in proportions such that the complex may be represented by the general formula: wherein w x and y each represents an integer, preferably less than 100; and z represents zero or an integer, preferably less than 100, It is preferred that x represents an integer from y to 2y and that the sum of x and 2y represents an integer from 0.5w to 1.5w.. The catalyst additionally may contain support material, for example carbon or silica, and/or a cuprene inhibitor, for example bismuth oxide, and/or an acid acceptor, for example calcium carbonate, and/or at least one copper acetylide complex other than the cuprous acetylide complex according to the invention. The catalyst may be prepared by a process in which formaldehyde and acetylene are reacted simultaneously with a particulate cupric compound, for example cupric oxide, cupric hydroxide, cupric silicate, cupric phosphate or a basic cupric carbonate, for example a synthetic malachite in which the CuO to CO 2 mole ratio is between I to I and 3 to 1. It is preferred that the cupric compound is in the form of particles having a cross-sectional dimension of at least 2.0 microns, has a surface area of at least 5.0 square metres per gram and contains less than 0.2 weight per cent of sulphur calculated as sulphate ion. The reaction may be effected in an aqueous medium and in the presence of an inert gas, for example nitrogen, methane or carbon dioxide. The particulate catalyst may be used in the ethynylation of a carbonyl compound by an acetylenically unsaturated hydrocarbon in an aqueous medium in the presence of the catalyst in slurry form. It is preferred that such ethynylation reaction is effected continuously and that the reaction mixture contains from 1 to 10 parts by weight of cuprous copper per 100 parts by weight of mixture. Examples relate to the preparation of 1, 4-butynediol (and propargyl alcohol) from formaldehyde and acetylene. |
