摘要 |
A process for the selective hydrogenation in the vapour phase, of 2-3C acetylenic hydrocarbons into the corresp. ethylenic cpds., which comprises passage of the acetylenic charge and H2 over a catalyst, in the form of balls or extrudates. The catalyst contains Pd, at least one gp. IB metal and Al2O3: the wt. ratio of the gp IB metal to Pd is 0.05-0.4 and at least 80% of the Pd and at least 80% of the IB metal is present in a defined vol. on the periphery of the catalyst. This vol. is defined by a spherical or cylindrical surface between a mean radius (of balls or extrudates) of r1 and a surface of radius r2, equal to at least 0.8 r. Also claimed, as a new prod. is the Pd base catalyst as defined above. |