Copper catalyst prepn. on support - with good mechanical and thermal stability and catalytic activity

摘要

A copper catalyst for hydrogenation and dehydrogenation is prepd. by pptn. of hydrated cupic oxide using alkali or carbonate on Kieselguhr with subsequent introduction of silica gel. Specif. the catalyst is 20-45 wt. % copper and the silica gel 15-75 pref. 20-40 wt. % w.r.t. the support. The hydrated cupic oxide-Kieselguhr is impregnated with a sol of silicic acid made from Na silicic acid made from Na silicate and nitric acid which is transformed to a gel by adjusting the pH to 7.5-8.5 and heating 50-100 degrees C. Copper catalysts facilitate hydrogenation and dehydrogenation, but not for 5 or 6 membered rings. The catalytic action of copper means that the catalysts must contain =20% copper and this high figure dictates the method of prodn., usually by co-pptn. with Al, Si or Cr oxides etc. or pptn. on silica gel, pumice stone and the like. These supports however are mechanically weak and do not lend themselves to tableting or moulding. The addn. of silica gel to the copper oxide-Kieselguhr matrix improved its mechanical and thermal stability whilst retaining catalytic activity and permitting tableting.