γ-Al_(2)O_(3)载体的水热合成及其加氢性能

Hydrothermal synthesis ofγ-Al_(2)O_(3)support and its hydrogenation performance

以ρ-Al_(2)O_(3)和NH4HCO3为原料,采用水热法合成出γ-Al_(2)O_(3)的前驱体碳酸铝铵(AACH),考察了原料配比和反应时间对合成产物的影响,利用X射线衍射仪、物理吸附分析仪、化学吸附仪对2种不同前驱体制得的载体进行表征,并对2种载体制得的催化剂进行了加氢脱硫脱氮性能评价。结果表明:在n(HCO_(3)^(-))/n(Al^(3+))为1.5∶1.0,100℃反应14 h下制得具有棒状结构、结晶度较好的AACH;相比由传统拟薄水铝石制得的载体,由AACH制得的载体具有较高比表面积和大孔容,有效孔径(4~10 nm)的孔容占比更高,且利于反应进行的中强酸更多,且所制备催化剂的脱硫脱氮活性更佳。

Ammonium aluminum carbonate hydroxide(AACH)as the precursor ofγ-Al_(2)O_(3)was hydrothermally synthesized fromρ-Al_(2)O_(3)and ammonium bicarbonate.The influences of reactants ratio and reaction time on the synthetic product were investigated.Supports obtained from two different precursor samples were characterized by X-ray diffractometer,physical adsorption analyzer,and chemical adsorption analyzer.The hydrodesulfurization and hydrodenitrification performance of corresponding catalysts were evaluated.The results showed that rod-like AACH with high crystallinity could be synthesized under the condition of the HCO_(3)^(-)to Al^(3+)mole ratio of 1.5∶1.0 at 100℃for 14 h.Compared with the support prepared by traditional pseudo boehmite,the support prepared by AACH had higher specific surface area and larger pore volume,the proportion of pore volume with effective pore size(4-10 nm)was higher,and more medium-strong acid was conducive to the reaction.And the desulfurization and denitrification activity of the prepared catalyst was better.