Water: Friend or foe in catalytic hydrogenation? A case study using copper catalysts

Abstract

Copper oxide supported on alumina and copper chromite were synthesized, characterized, and subsequently tested for their catalytic activity toward the hydrogenation of octanal. Thereafter, the impact of water addition on the conversion and selectivity of the catalysts were investigated. The fresh catalysts were characterized using X-ray diffraction (XRD), BET surface area and pore volume, SEM, TEM, TGA-DSC, ICP, TPR, and TPD. An initial catalytic testing study was carried out using the catalysts to optimize the temperature and the hydrogen-to-aldehyde ratio—which were found to be 160 °C and 2, respectively—to obtain the best conversion and selectivity to octanol prior to water addition. Water impact studies were carried out under the same conditions. The copper chromite catalyst showed no deactivation or change in octanol selectivity when water was added to the feed. The alumina-supported catalyst showed no change in conversion, but the octanol selectivity improved marginally when water was added.