【摘要】 用 TPSR、 NH3-TPD、 XPS、 EPR和 UV-DRS等手段对担载型镍催化剂上丙烯吸附与齐聚反应的特征进行了系统的考察。结果发现 ,以 Si O2 -Al2 O3、γ-Al2 O3、HZSM-5为载体的镍催化剂上 ,除两类强弱不同的酸中心外 ,还存在第 3类活性中心 ,即配位型镍催化活性中心。催化剂表面 Ni+是丙烯吸附与齐聚反应的活性中心 ,并提出一种新的丙烯齐聚反应机理。更多还原

【Abstract】 The nature of adsorption and oligomerization of propylene on nickel based catalysts was extensively investigated by combining techniques,such as temperature programmed surface reaction(TPSR),temperature programmed desorption of ammonia (NH 3 TPD),X ray photoelectron energy spectroscopy(XPS),electron paramagnetic resonance(EPR),and ultraviolet differential reflection spectroscopy (UV DRS).There are three kinds of active sites existed on the surface of supported nickel catalysts,the strong acid site(720～820 K),the weak acid site(540～580 K)and the third one which in fact is the complex nickel based sites.Further characterizations showed that surface anchored Ni + may be the active sites for the adsorption and oligomerization of propylene and that [Ni(C 3H 6)] +, [Ni(C 3H 6) 2] + and [Ni(P)] + may be the active intermediates of oligomerization of propylene. The possible activation pattern of nickel based catalysts and the mechanism of propylene oligomerization were also postulated.更多还原