Characterization of catalysts with techniques of XRD, TG, etc.

The crystal structure of a certain sample was evaluated by powder X-ray diffraction (XRD, D8 Advance, Germany) using Cu Kα radiation (λ= 0.15418 nm) at 40 kV, 30 mA, with a scan step of 0.02° and a 2θ ranging from 5 to 75 °. The 77K-N2 adsorption-desorption isotherm of a certain sample was measured by using a Micromeritcs ASAP2010 instrument. Then the specific surface area and pore-size distribution of this catalyst was calculated using the Brunauer–Emmett–Teller (BET) method for the adsorption branch and the Barret–Joyner–Halenda (BJH) method for a desorption branch, respectively. The thermogravimetric (TG) analysis of a certain catalyst was carried out in an air flow of 50 ml/min by using a HCT-1 thermal analytical instrument. The sample weight was ~10 mg and the typical heating rate was 10 K/min.