摘要
采用PASCA、IR、化学分析及微反等技术,研究Pt/Al_2O_3和Pt-Re/Al_2O_3体系中金属与载体之间的相互作用。结果表明:氯在铂、铼与氧化铝之间的相互作用及对催化剂芳构化活性的影响方面起着十分重要的作用。在没有氯存在的情况下,铂(或铂-铼)与氧化铝之间是不存在相互作用的。当浸渍液中存在氯时,铂以[PtCl_6]^(2-)络离子形式取代氧化铝表面上某些活泼OH^-基,生成稳定的金属—载体相互作用复合物(MSIC)。而生成稳定MSIC的合适盐酸浓度为0.4 mol/L。这一结果与文献报导是一致的。 实验结果还表明,在探讨金属与载体之间的相互作用时,非金属元素(如氯等)是一个十分重要而不可忽视的因素。
PASCA (Positron Annihilation Spectroscopy for Chemical Analysis), in conjunction with IR, chemical analysis and microreactor technique, was used to investigate Pt/ Al2O3 and Pt- Re/ Al2O3 catalytic systems. The results show that chlorine plays a special role in the interaction between metal (Pt or Pt-Re) and its supported material (Al2O3), and consequently considerably affects the aromatization activity of the catalysts. Without chlorine, Pt (or Pt-Re) itself can hardly interact with the surface of alumina. However by impregnating Al2O3 with Pt-HCl solution, the Pt, in its anionic form [PtCl6]2-, will replace some kind of the active hydroxyl groups (OH-) from alumina surface, and form stable MSIC(metal-support interaction complex).
出处
《分子催化》
EI
CAS
CSCD
1992年第6期434-439,共6页
Journal of Molecular Catalysis(China)
基金
国家自然科学基金资助课题
关键词
催化剂
铂
氧化铝
PASCA
Metal-support interaction complex
Catalyst.
