TiO 2 nanotube-supported ruthenium(III) hydrated oxide: A highly active catalyst for selective oxidation of alcohols by oxygen

Abstract

Ruthenium(III) hydrated oxide was deposited onto the surface of TiO 2 nanotubes via ion exchange followed by alkali treatment. The catalytic activity of Ru(III)/TiO 2 catalyst for the selective oxidation of alcohols by oxygen was studied in a continuous multichannel, compact reactor. It was found that the activity of Ru(III)/TiO 2 (turnover frequency [TOF] ⩽ 450 h −1) is greater than that of a recently reported Ru(III)/Al 2O 3 catalyst (TOF = 335 h −1), and that the ruthenium loading could exceed 8 wt% without any significant loss of specific catalytic activity. High-resolution transmission electron microscopy and X-ray diffraction data show that ruthenium is highly dispersed on both the inner and the outer surfaces of the mesoporous TiO 2 nanotubes with the diameter of nanoparticles between 1.2 and 2.4 nm, and is easily accessible by reactant molecules.