Abstract:
PROBLEM TO BE SOLVED: To obtain an excellent method for producing a hydrogenating catalyst easily executed as compared with a conventional method by treating a carbon- containing catalyst carrier with a specific compd. SOLUTION: A carbon-containing catalyst carrier is treated with a compd. represented by formula (wherein M is Ti or Zr, X is Cl or Br, R is a 1-20C alkyl group and (m) and (n) are an integer of 0-4 and the sum of (m) and (n) is 4). Therefore, a hydrogenerating catalyst can be easily produced. Especially, a platinum-containing hydrogenating catalyst used in the production of a hydroxylammonium salt is produced by precipitating platinum on a carbon- containing catalyst carrier in an aq. medium by using a reducing agent and, if necessary, partially poisoning a catalyst with a sulfur-containing compd. prior to this but, in this case, a carbon-containing catalyst pretreated with the compd. represented by the formula is used. Therefore, the novel carbon- containing catalyst carrier can be used in the production of a platinum- containing hydrogenating catalyst.
Abstract:
PROBLEM TO BE SOLVED: To obtain a catalyst having a long life with a minimum extent of nitrous oxide formation by using the specified ammonium salt or phosphonium salt as a reductant for reducing in the presence of a carboniferous support in an aq. medium with the reductant after partial poisoning to prepare a hydrogenation catalyst. SOLUTION: A hydrogenation catalyst suitably used for preparation of hydroxyl ammonium salts is prepared by reduction with a reductant in the presence of a carboniferous support in an aq. medium after partial poisoning a sulfur, arsenic, tellurium, or antimony-contg. compd. And, as the reductant, an ammonium or phosphonium salt expressed by the formula [XR4 ]n Y is used. In the formula, X stands for N or P, R stands for hydrogen, 1-18C alkyl, 5-10C cycloalkyl or the like, or n is an integer of 1-3 if X is P, and Y stands for an org. anion which can reduce platinum in an oxidation stage other than zero to platinum in the oxidation stage of zero.