Catalytic composition, method for manufacturing thereof and method for the purification of terephthalic acid
||Патент на изобретение
||US 6753290 B1
|Номер заявки (21):
|Дата подачи заявки (22):
||9 дек. 1999 г.
|Дата начала отсчета срока действия патента (24):
|Дата публикации патента (44,45,46):
||22 июн. 2004 г.
|Дата публикации заявки (43):
The present invention relates to catalyst compositions for purifying terephthalic acid from p-carboxybenzaldehyde, based on Group VIII metals, comprising crystallites of catalytically active palladium or of palladium and at least one metal of Group VIII of the Periodic Table of Elements, applied to the surface of a carbon material, wherein a mesoporous graphite-like material with the average mesopore size in the range of from 40 to 400 Å, the proportion of the mesopores in the total pore volume of at least 0.5, and the degree of graphite-similarity of at least 20% is used as the carbon material, in which metal crystallites are distributed in the volume of the carbon material granules in such a manner that the distribution peaks of these crystallites should be at a distance from the outer surface of the granule corresponding to 1-30% of its radius. The present invention also relates to a method for preparing catalyst compositions, and to a method of purifying terephthalic acid suitable for the subsequent synthesis of polyester polymers and copolymers used in the manufacture of textile fibers.