摘要
烃类汽转化催化剂Ni/α—Al_2O_3的抗积碳性能随镍晶粒分布有显著变化。本文用X—射线小角散射法对镍晶粒分布进行了测定,用正庚烷蒸汽转化反应测定了催化剂抗积碳性能。结果表明,镍催化剂的积碳速率随大晶粒比率的增加而加快。用适量稀土氧化物(La_2O_3)将载体进行改性,能增强金属—载体之间的相互作用,镍的分散度显著增加,从而可提高镍催化剂的抗结碳性能。考察了高温(987K)水热处理后不同镧含量催化剂的抗积碳性能。结果表明,随着水热处理时间的延长,镍晶粒先熔结变大,到一定程度后再分散变小。与其对应,积碳速率先增大到一个峰值,然后下降。
The crystal size distribution was determined with small angle X-ray scaterring(SAXS) techmique.The anticoking property of the catalysts was studied with steam reforming of n-heptane in a TG-monitored flow reactor.The experimental results show that the rate of carbon formation on catalysts mainly depends on percentage content (of large crystal size (25~70nm) fraction,and the dispersion of nickel and the anticokingability) of La2O3-modified Ni/a-Al2O3 catalysts increased obviously due to the strong metal-support interaction(SMSI).The variations of Ni crystal size distribution andanticoking behavior were investigated after the different periods of hydr thermal treatment of the catalysts,and then decreased via a peak,correspondingly exists the decreases of percentage content of large crystal size fraction.
出处
《石油大学学报（自然科学版）》
CSCD
1991年第1期95-100,共6页
Journal of the University of Petroleum,China(Edition of Natural Science)
关键词
催化剂
镍
粒度
抗积炭性
Nickel
Catalyst
Particle size distribution
Anticoking behavior
Carbon forming rate
