Ru/ReO_x/TiO₂ Selective and Reusable Catalyst for C−O Hydrogenolysis of C₄ Polyols

Abstract

This study reports the selective obtaining of butanediols, mainly 23BDO and 12BDO isomers, by C−O hydrogenolysis of erythritol on Ru (2 %wt.) supported on titania at 473 K and 25 bar H2 and their modification with Re species that improve the selectivity to C−O hydrogenolysis over other reactions (C−C hydrogenolysis, dehydration, etc). The dependence of the catalytic activity with reaction temperature and reactants concentrations is also discussed. Characterization by XPS, TEM and TPR indicates that the surface of rhenium modified Ru is formed by small particles (<3 nm) of Ru0 in contact with Re+IV (Re/Ru molar ratio ≈1). Over this catalyst (Ru/ReOx/TiO2) close or even higher BDO yields than previous values reported on other noble metals were obtained, making it very attractive since Ru is more economical than Pt, Ir or Rh metal. Furthermore, we demonstrate that Ru/ReOx/TiO2 was also stable and allowed to be reused in at least three consecutive reactions.