焙烧温度对非负载Ni-Mo-Al_2O_3催化剂加氢脱氧性能的影响

采用热分解硝酸镍和钼酸铵的方法制备了Ni-Mo-Al2O3非负载催化剂。分别以乙酸、苯酚为探针分子,在连续流动固定床反应器上评价了催化剂的加氢脱氧活性,并采用XRD、BET、XRD、EDS等技术对催化剂进行了表征,着重考察了焙烧温度对催化剂的晶态结构、表面元素相对含量及催化性能的影响。结果表明,随着焙烧温度的升高,催化剂的比表面积增大,晶化程度提高,焙烧温度550℃时,催化剂表面Ni、Mo、Al的比例达到最优,并具有最好的加氢脱氧活性。在250℃、0.4 MPa条件下,乙酸的脱氧率达到96.0%;在200℃、0.3 MPa条件下,苯酚的脱氧率达到96.8%。

Effects of calcination temperature on the properties of unsupported Ni-Mo-Al2O3 catalysts for hydrodeoxygenation

The un-supported Ni-Mo-Al₂O₃ catalysts were prepared using the thermal decomposition method with nitrate hexahydrate and ammonium paramolybdate as precursors. The evaluation of hydrodeoxygenation activity of the catalysts was conducted in a continuous flow fixed-bed reactor, using the acetic acid and the phenol as probe compound. The catalysts were characterized using specific surface area (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrdmeter (EDS). The effects of calcination temperature on the catalyst crystalline structure, element relative content and activity were investigated emphatically. The results show that the surface area of the catalysts increases and the crystallization degree of catalysts were improved with increasing the calcination temperature. The Ni/Mo/Al radio on surface of the catalysts calcined at 550℃ was optimal, and the catalyst exhibited the highest hydrodeoxygenation activity, and the deoxygenation percentage of the acetic acid was 96.0% at 250℃, 0.4MPa and the deoxygenationa percentage of the phenol was 96.8% at 200℃, 0.3MPa.