无机盐工业
主管:中海油天津化工研究设计院有限公司
主办:中海油天津化工研究设计院有限公司
   中海油炼油化工科学研究院(北京)有限公司
   中国化工学会无机酸碱盐专业委员会
ISSN 1006-4990 CN 12-1069/TQ

无机盐工业 ›› 2011, Vol. 43 ›› Issue (4): 18-.

• 论文 • 上一篇    下一篇

镧钡掺杂量对氧化铝孔结构的影响

贺小昆,刘沁曦,覃庆高,郭律   

  1. 昆明贵研催化剂有限责任公司,云南昆明 650106
  • 发布日期:2011-04-19

Influence of La/Ba doping content on pore structure of alumina

He Xiaokun,Liu Qinxi,Qin Qinggao,Guo Lü   

  1. Kunming Sino-Platinum Metals Catalyst Co.,Ltd.,Kunming 650106,China
  • Published:2011-04-19

摘要: 采用纯γ-氧化铝,制备含镧/钡质量分数为5%、10%、20%、30%的系列改性氧化铝,样品分别在550、950、1 050、1 200 ℃条件下进行煅烧,采用比表面积、孔容、孔径、XRD表征老化前后的改性氧化铝孔结构,研究不同镧/钡含量对改性氧化铝孔结构特征的影响。BET和XRD结果表明,镧、钡在高温时产生的大量铝酸盐结构可抑制γ-Al2O3相转变,有利于保持γ-Al2O3相结构稳定性和孔结构稳定性,同时较高镧/钡含量也会导致改性氧化铝比表面积降低、孔容、孔径下降,尤其是1 200 ℃高温区表现更为明显,对活性金属分散存在负面影响。综合考虑孔结构和衰减率因素认为,2.5%La2.5%Ba/Al2O3具有最好的表面活性和孔结构稳定性。

关键词: 三效催化剂, 氧化铝, 碱金属, 催化活性

Abstract: A series of modified alumina with different mass fractions (5%, 10%,20%,and 30%) of La/Ba were prepared by γ-Al2O3.All samples were calcined at 550,950,1 050,and 1 200 ℃ respectively.Pore structure of all samples were characterized by BET,pore volume, pore diameter,and XRD before and after aging.Influence of La/Ba doping contents on pore structure of modified Al2O3 was studied.Results of BET and XRD demonstrated that La/Ba can form large amount of aluminate structure to inhibit γ-Al2O3 phase tranfer at high temperature and is good for maintaining stability for both phase structure and pore structure of γ-Al2O3.Meanwhile,higher La/Ba content can decreased the surface area,pore volume,and pore diameter,and is not good for precious metals dispersing,especially at 1 200 ℃.Comprehensively considering pore structure and loss rate,2.5%La2.5%Ba/Al2O3 has the optimal surface activity and pore structure stability. 

Key words: three-way catalyst, alumina, alkali metals, catalyst activity

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