Hydrolysis of acrylonitrile to acrylamide over an ion-exchanged copper on silica catalyst

The deactivation of a copper on silica catalyst prepared by the ion-exchange technique for the hydrolysis of acrylonitrile (AN) to acrylamide (AA) has been studied at temperatures below 350 K. Initial deactivation is attributed to a polymer network coating the outer particle surface and originating from the product. Due to the nature of the polymer and the fine catalyst support pore structure, a major part of the active copper sites remains accessible and the catalyst retains its activity over a long time and broad range of reactant and product concentrations, but undergoes very slow and constant deactivation by copper oxidation from oxygen dissolved in the reactant mixture. The level of almost constant activity is distinctly higher than for other copper-based catalysts and is described by the power law rate equation r=1.80 exp (-5910/T) C^0.80 _AN C^-0.12 _AA.