Pd(II) and Pd(0) catalysts supported onto titanate nanotubes (H2Ti3O7) were prepared by an ion-exchange technique. The catalysts are characterised by narrow size distribution of metal nanoparticles on the external surface of the nanotubes. Pd(II) catalysts show high selectivity toward double-bond migration reaction versus hydrogenation in linear olefins. The catalytic activity exhibits a volcano-type dependence on the metal loading, with the maximum activity observed at ca. 8 wt%. The Pd(II) was shown to be rapidly reduced to Pd(0) by appropriate choice of solvent. Prereduced Pd(0) catalysts were found to be less active toward double-bond migration and more selective toward hydrogenation. The DBM reaction was faster in protic solvents, such as methanol or ethanol.
Torrente Murciano, L., Lapkin, A., Bavykin, D., Walsh, F., & Wilson, K. (2007). Highly selective Pd/titanate nanotube catalysts for the double-bond migration reaction. Journal of Catalysis, 245(2), 272-278. https://doi.org/10.1016/j.jcat.2006.10.015