An evaluation of alkylthiols and dialkyl disulfides on deactivation of Cu/Zn catalyst in hydrogenation of dodecyl methyl ester to dodecanol

Deactivation of co-precipitated Cu/Zn catalyst caused by exposure to either alkylthiols or dialkyl disulfides in catalytic hydrogenation of dodecyl methyl ester to dodecanol is explored in a stirred batch reactor. Catalytic activity decrement is highly dependent on levels of poisons, types of thiols/disulfides, chain length of alkanes. XRD, EDS and XPS are employed to characterize the fresh and spent Cu/Zn catalysts. It is evident that sulfuric species prefer to attack zinc oxide, forming chemically adsorbed Zn-SR at low sulfur levels, and ZnS is formed in the highly reductive atmosphere before sulfuric species attacking copper (forming Cu7S4 or Cu31S16). (C) 2013 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.