Tio2 rutile

All chemicals were used as received. Rutile TiO₂ (<5 μm, ≥99.9%), tetramethylammonium bromide (TMAB, ≥98.0%), NaNO₃ (≥99.0%), sodium hydroxide (NaOH, 99.9%), hydrochloric acid (HCl, 37%), methanol (99.5%), and ethanol (99.5%) were purchased from Sigma--Aldrich. HNO₃ solution containing Pd(NO₃)₂ (0.216 M) was purchased from Kojima Chemicals Co., Ltd. Tetraethyl orthosilicate (TEOS, >97.0%) was purchased from Tokyo Chemical Industry.

Analytical grade fine powder titanium dioxide (Degussa P25, 75% anatase, 25% rutile); Anatase TiO₂ (IshiharaSangyo, Japan); Rutile TiO₂ (99.995%, Sigma-Aldrich); Ammonia gas (anhydrous, BOC) were used without further purification.

The TiO₂ supports used for the preparation of Ru-based catalysts in this work were consisted of TiO₂ anatase (Alfa Aesar), TiO₂ rutile (Sigma Aldrich), TiO₂-P25 (Degussa), and TiO₂ prepared by sol–gel method. The TiO₂ mixed phase support was prepared by using sol–gel method as follows. Approximately 83.5 cm³ of titanium isopropoxide (Sigma Aldrich) as TiO₂ precursor was added into the solution containing nitric acid (HNO₃, 65 vol%) in deionized water (7.3 cm³ HNO₃: 1000 cm³ H₂O). Then, the mixture solution was continually stirred at room temperature for 3 day until the clear sol was obtained. The clear sol was placed and dialyzed in cellulose membrane, which was submerged in the deionized water, for 3 day. During dialyzing, the water was daily changed until the pH of water reached about 3.5. After that, the resulting sol was dried in oven at 110 °C for 12 h. The dried sol was milled and then calcined in air flow at 350 °C for 2 h with heating rate of 10 °C/min.