Deactivation and regeneration of an activated carbon-supported nickel catalyst for methanol carbonylation in the vapor phase

The stability, deactivation and regeneration of a Ni/AC catalyst for methanol carbonylation in the vapor phase were studied. The results revealed that deactivation was mainly caused by carbon deposition and an increase in Ni particle size. Limitation of the internal diffusion of acetic acid and/or methyl acetate was confirmed by Py-FTIR, as could explain the slow deactivation observed in the initial stage of the reaction. Further study revealed that the deactivated catalyst was easily regenerated in H-2 flow at 400 degrees C. The deactivation of regenerated catalyst occurred more rapidly due to the bigger Ni particle size. (C) 2008 Elsevier B.V. All rights reserved.