Catalytic composition, method for manufacturing thereof and method for the purification of terephthalic acid
||Заявка на патент
||JP 2001096157 A
|Номер заявки (21):
|Дата подачи заявки (22):
||27 июл. 2000 г.
|Дата начала отсчета срока действия патента (24):
|Дата публикации патента (44,45,46):
|Дата публикации заявки (43):
||10 апр. 2001 г.
PROBLEM TO BE SOLVED: To provide a catalyst for purification of terephthalic acid through a selective hydrogenation of crude terephthalic acid having a high content of p-CBA to p-toluic acid and/or decarbonylation of a low content of the residual p-CBA to benzoic acid, a production method for the catalyst, and a purification method for terephthalic acid using the catalyst. SOLUTION: A catalyst for purification of terephthalic acid comprises palladium deposited on a carbon material or crystals of palladium and at least one metal element of group VIII of the periodic table. The carbon material has an average mesopore size in the rage of 40-400 Å, and a ratio of the mesopore volume to the total pore volume of 0.5 or more, and is a graphite-like material having graphite-likeness of 20% or more, about an intermediate degree of porosity. The crystals of the metals and the like are distributed through the bulk of granules of the carbon material so that a layer is at a distance from the surface of the granule equal to 1-30% of the radius thereof. Crude terephthalic acid is purified by using the catalyst.