The Ru/TiO2 catalyst was synthesized by a direct chemical reduction method, RuCl3 (Ruthenium (III) chloride hydrate, 99.9% (PGM basis), Alfa Aesar) was used as the ruthenium precursor. A 6 mM RuCl3 solution was prepared with 100 ml ultra-filtered water (Milli-Q Millipore, 18.2 MΩ cm) in vigorous stirring for 5-10 minutes in a three necked round bottom flask. The support TiO2 (1.00 g, AEROXIDE TiO2 P90 Evonik) was added to the mixture. The dispersion was left in vigorous stirring for at least 1 hour at 100 °C. A 0.18 M NaBH4 solution was prepared using demineralized water. 10 ml of this solution was added to the previous mixture using a pump with a flow rate of 3 ml/min and the mixture was left stirring for an extra 30 minutes. The solid was recuperated by filtration and extensively washed with ultra-filtered water. Further characterization details can be found in the Supplementary Information.