摘要
用环烷酸镍浸渍法制备了载镍的超稳Y分子筛并用XPS研究了它们在氧化再生条件下的表面性质.结果表明,沉积在分子筛外表面的镍能够向分子筛体相移动,分子筛中的金属阳离子如Na^+、La^(3+)和非骨架铝等对镍的移动有阻抑作用,高温水蒸气处理则促进镍的移动.沉积镍主要以+2价存在,但可形成不同的表面物种.
The surface composition and element binding energy for a series of nickeldeposited USY and LaHY zeolite samples were studied by XPS. It was found that the higher the metal cation (such as Na^+,La^(3+) and non-framework aluminum) content in zeolite, the higher the nickel content on external surface of zeolite, and that the nickel content on external surf ace of zeolite decreases after high temperature steam treatment. These results suggest that the deposited nickel can migrate into the bulk phase of zeolite under oxidative condition. This migration is hindered by metal cations but enhanced by the presence of H^+ in zeolite. High temperature steam treatment also enhances the migration. It was also found that the binding energy of nickel varies with surface Ni/Siand Al/Si ratios in the range of 855.3～857.1 eV, suggesting that nickel is mainly present in bivalent state, but may form different compounds depending upon nickel-zeolite interaction.
出处
《石油学报（石油加工）》
EI
CAS
CSCD
北大核心
1990年第2期27-32,共6页
Acta Petrolei Sinica(Petroleum Processing Section)
