PSS辅助水热合成分级结构纳米γ-Al_2O_3及其CO_2吸附性能增强

PSS-Assisted Hydrothermal Synthesis of Hierarchical γ-Al_2O_3 Nanostructures with Enhanced Adsorption Performance Towards CO_2

以AlCl_3·6H_2O为铝源、CH_3COOK为沉淀剂、聚苯乙烯磺酸钠(PSS)为结构调节剂,采用温和水热焙烧法成功地制备了系列对CO_2吸附性能增强的分级结构纳米γ-Al_2O_3。采用XRD、SEM和N2吸附-脱附等手段,对比研究了PSS浓度对产物物相结构、形貌、织构性质及其在室温下对CO_2吸附性能的影响。研究表明,PSS对产物形貌、织构性质及其CO_2吸附性能具有明显的调控作用。不添加PSS时产物表现为不规则的块状粒子,PSS浓度依次增加到2、4和6 g·L^(-1)后,产物分别表现为不规则的棒状团簇体微米级粒子、类球形棒状团簇体微米级粒子、相互交织的纤维状微米级粒子,并且其比表面积和孔容逐渐增加;添加PSS后产物的CO_2吸附量增加、吸附动力学加快,尤其是PSS浓度为6 g·L^(-1)时,相应产物的最高吸附量为0.68 mmol·g^(-1),6次循环再生后其吸附量仍基本保持稳定。

Series of hierarchical γ-Al2O3 nanostructures with enhanced adsorption performance towards CO2 were successfully synthesized via a facilely hydrothermal method-calcination route using AlCl3.6H：O as aluminum source, CH3COOK as precipitant and poly（sodium 4-styrenesulfonate） （PSS） as structure directing agent, respectively. Effects of PSS concentration on the phase structure, morphologies, textural properties of the as-prepared γ-Al2O3 and their adsorption performance towards CO2 at 25℃ were comparatively characterized by X-ray powder diffraction （XRD）, scanning electron microscopy （SEM）, N2 adsorption-desorption techniques. It was shown that PSS plays an important role in controlling the morphologies, textural properties and adsorption performance of the γ-Al2O3. The γ-Al2O3 obtained without PSS shows irregular massive particles. With increasing its concentration to 2, 4 and 6 g· L^-1, respectively, the corresponding γ-Al2O3 show irregular nanorods cluster-like micron particles, spherical-like cluster composed of nanorods and interwoven fibrous micron particles, respectively, and their specific surface area and pore volume gradually increase in turn. In comparison with the γ-Al2O3 obtained without PSS, the T-A1203 obtained with PSS show higher adsorption capacity and faster adsorption kinetics. Especially, when the PSS concentration is 6 g·L^-1, the γ-Al2O3 has the highest adsorption capactiy of 0.68 mmol ·g-1, and shows stable adsorption capactiy after consecutive recycle times of 6.