Hydrogenation activity of an amorphous Pd-Zr alloy held in an alumina matrix

The hydrogenation of benzene has been carried out over a catalyst prepared from an amorphous Pd-Zr alloy held in an alumina matrix. The catalytic activity was compared with that over the alloy cut into 1 mm fragments. It was found that the fixed alloy in the alumina had not only higher catalytic activity, but also a smaller catalyst fouling rate than the fragments of the alloy. The effect of palladium content in the amorphous alloy on the hydrogenation activity was examined. It was found that the initial activity increased with the fraction of palladium. However, the activity of the catalyst which had the highest palladium content decreased with repeated regeneration and reaction, whereas the activity of the other catalysts reached a stable value. On a effectue l'hydrogenation du benzene a l'aide d'un catalyseur prepare a partir d'un alliage amorphe de Ph-Zr depose sur une matrice d'alumine. L'activite catalytique a ete comparee a celle de l'alliage decoupe en fragments de 1 mm. On a trouve que l'alliage fixe dans l'alumine a non seulement une activite catalytique plus elevee, mais egale-ment une vitesse d'encrassement du catalyseur plus petite que dans le cas des fragments d'aliiage. On a examine l'effet de la teneur en palladium dans l'alliage amorphe sur l'activite d'hydrogenation. On a trouve que l'activite initiale augmente avec la fraction de palladium. Cependant, l'activite du catalyseur qui a la plus haute teneur en palladium diminue a la suite d'une regeneration et d'une reaction repetees, alors que l'activite des autres catalyseurs atteint une valeur stable.