Mg-Al复合氧化物的制备及吸附苯酚动力学

Synthesis of Mg-Al-LDOs and Their Adsorption Kinetics towards Phenol

分别采用共沉淀-室温晶化和共沉淀-水热法、经焙烧合成了Mg-Al复合氧化物,对比研究了两种处理对产物物相、形貌、织构性质及吸附苯酚动力学的影响。结果表明,后者使产物的结晶度略有提高,使其比表面积、孔容和平均孔径相应减少,但对形貌影响不大;吸附苯酚的过程均适合拟二级动力学方程,但后者使产物的吸附速率加快,吸附容量增加。

Mg-Al layered double hydroxides（LDHs） were prepared by coprecipitation-natural crystallization and coprecipitation-hydrothermal method,respectively,and sequential calcination route.The effects on the phase,morphology,textural properties and adsorption kinetics towards phenol of the as-prepared samples by these two methods were comparatively investigated.The results showed that the crystallinity of the sample increases a little,and its specific surface area,pore volume and average pore size decreases respectively,while there is no obvious change of the morphology via hydrothermal treatment.The pseudo-second-order kinetics model can well describe the adsorption process.However,the latter has faster adsorption rate and higher theoretical adsorption capacity than that of the former.