固相法合成梯度孔γ-Al_2O_3及其形成机制  

Synthesis of Hierarchical Porous γ-Al_2O_3 by Solid-State Reaction and Its Formation Mechanism

作　　者：胡小夫[1,2] 柳云骐[2] 李国良[2,3] 马跃龙 刘晨光[2] 

机构地区：[1]中国华电集团科学技术研究总院,北京100077 [2]中国石油大学重质油国家重点实验室,山东青岛266555 [3]北京燃气绿源达清洁燃料有限公司,北京100772

出　　处：《石油学报（石油加工）》2015年第3期684-690,共7页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：国家重点基础研究发展计划'973'项目(2010CB226905)资助

摘　　要：以硝酸铝和碳酸氢铵为原料、PEG-400为形貌诱导剂,采用低温固相反应,在温和条件下制备出棒状碳酸铝铵(AACH),AACH焙烧后形貌和尺寸经拓扑转化,得到具有开放性孔道结构、高比表面积和大孔容的梯度孔γ-Al2O3。采用XRD、BET、SEM方法对AACH和梯度孔γ-Al2O3进行了表征。考察了棒状AACH在热转化过程中物相和形貌的改变以及形貌诱导剂PEG-400对梯度孔γ-Al2O3织构性能的影响,探讨了梯度孔γ-Al2O3的形成机制。结果表明,通过调节PEG-400的用量可调变AACH的形貌,从而可调控γ-Al2O3纳米粒子的形貌,最终得到比表面积高达422.1m2/g、孔容为1.90mL/g的梯度孔γ-Al2O3。梯度孔γ-Al2O3中,3~6nm尺寸的孔由棒状AACH焙烧产生气体的扩孔作用形成,10~35nm尺寸的孔由棒状γ-Al2O3纳米颗粒堆积形成。Ammonium aluminum carbonate hydroxide （AACH） with nanorods morphology was synthesized by a low-temperature solid-state reaction with NH4HCO3 and Al（NO3）3 as reactants and PEG-400 as morphology inducer. Meanwhile, the hierarchical porous y-A12 03 with open porous structure, high surface area and large pore volume was obtained by a topological transformation of the morphology and size of AACH after calcination. The synthesized AACH and hierarchical porous ^-A1203 samples were then characterized by means of XRD, BET, SEM. The change of the phases and morphologies of AACH during thermal conversion and the influence of PEG-400 for the textural properties of hierarchical porous y-A1203 were investigated. The formation mechanism of hierarchical porous y-AlzO3 was also discussed. The results demonstrated that the morphology of AACH could be controlled by adjusting the dosage of PEG-400, thereby the morphology of y-A12 03 was indirectly regulated, and finally the hierarchical porous 1＇-A1203 product with high surface area （422.1 ma/g） and large pore volume （1.90 mL/g） was obtained. The formation of hierarchical porous y-A1203 is possibly attributed to the pore enlargement of gas produced from the calcination of AACH, resulting in the hole with the size range of 3--6 nm, and the stacking of y-A1203 nanoparticles, resulting in the hole with the size range of 10--35 nm.

关 键 词：梯度孔 氧化铝 低温固相 合成 

分 类 号：TE624.4[石油与天然气工程—油气加工工程]