| 摘要 |
PROBLEM TO BE SOLVED: To improve a catalyst life by depositing palladium more on the surface layer part of a porous carbon carrier than in this carbon carrier and forming the palladium particles in the surface layer part of the carbon carrier to the diameter larger than the diameter of the palladium in the carrier at the time of depositing the palladium on the carbon carrier. SOLUTION: The catalyst for hydrogenation deposited with the palladium on the porous carbon carrier is formed by adding the carbon carrier into an aq. soln. of a palladium salt to adsorb part of the palladium salt on the carbon carrier, then adding a reducing agent to the soln., thereby reducing the palladium salt and depositing the palladium on the surface of the carbon carrier. At this time, the palladium is deposited more on the surface layer part of the carbon carrier than the inside of the carbon carrier and the palladium particles of the surface layer part of the carbon carrier is formed to the diameter larger than the diameter of the palladium particles within the carrier. In addition, the pH of the aq. soln. of the palladium salt is set at a range of 0.7 to 2.0 in order to control the particle size distribution of the palladium particles and the position on the carbon carrier on which the palladium particles are deposited. |
