A Novel Method for Preparation of Activated Alumina-Experimental PartⅡ

1.3 Characterization of activated alumina

The XRD spectrum of the sample was measured on a Panalytical X 'Pert Pro X-ray diffractometer. Tube voltage 40 kV, tube current 30 mA, Cu Kα radiation source (λ= 0.154 06 nm), scanning range 2θ= 10°～90° . The specific surface area of the sample was measured using a Micromeritics Tristar 3000 adsorption instrument. The sample was pre-evacuated at 200°C for 2 h, and N₂ was the adsorbate (adsorbed at - 196°C). The specific surface area was calculated using the BET method, and the pore volume and pore size distribution were calculated using the BJH method, and the micropore volume was calculated according to the t=plot method. The NH3=TPD spectrum was measured on a Micromeritics AutoChem II 2920 analyzer. The sample (100 mg) was previously treated with He gas flow (20 ml/min) at 500 °C for 30 min, after the sample temperature drops to 80 ℃, introduce NH₃ to adsorb to saturation, then switch to purge with He gas flow (30 ml/min). After the baseline is stable, perform ammonia programmed temperature-raising desorption (heating from 80 ℃ to 650 ℃ at a rate of 10 ℃/min).

1.4 Evaluation of Catalyst Activity

Catalyst activity evaluation was carried out in a homemade fixed-bed high-pressure continuous reactor. The catalyst (0.15 ml) was reduced in advance in a 0.5 MPa H₂ gas flow (100 ml/min) at 400 °C for 4 h, and then in an ethylbenzene volume space velocity of 1.33 h ^{- 1}, the ethylbenzene hydrogenation catalytic reaction was carried out under the conditions of H₂ flow rate 100 ml/min and pressure 1.0 MPa. Product analysis was performed on a Shanghai Haixin GC=950 gas chromatograph (SGE=AC20 column ) equipped with a hydrogen flame detector.