Regeneration of pd-catalyst poisoned by co impurities - from h2 used for catalytically reducing no3-ions to

摘要

Regeneration of Pd-catalyst poisoned by CO impurities from H2 used for catalytically reducing NO3-ions to NH2OH N6A. Involves treating a suspension of the largely inactivated Pd catalyst (I) in the normal reaction medium with O2 or O2-containing gas, especially air, generally at 20-60 degrees C, pH 0-3, under atmospheric- or elevated pressure. Hydrogen gas purification systems do break down at times in which case the costly (I) must be renewed. The new procedure allows the poisoned (II) to be reactivated in 1 hr.