Effects of support and metal loading on the characteristics of Co based catalysts for selective hydrogenation of citral

Silica-, alumina- and titania-supported Co catalysts with different metal loadings were tested for selective citral hydrogenation in liquid phase. Temperature programmed desorption of hydrogen (H2-TPD) indicated that the catalysts with the highest unsaturated alcohols selectivities present particular H-Co species. Electron diffraction and XRD measurements revealed that these species would be linked to the presence of Co0 hexagonal phase. According to the results obtained by TEM and cyclohexane dehydrogenation, these two properties would be present on large Co particles.

Silica-, alumina- and titania-supported Co catalysts were tested for selective citral hydrogenation. Three factors were found to be crucial to achieving high selectivity to unsatutared alcohols in the course of citral hydrogenation. These factors include a particular H-Co species (labelled β), the Co0 hexagonal phase and a large size of particles. Figure optionsDownload as PowerPoint slide