【摘要】 以乙醇为溶剂,在常压、温度180℃、己二腈液时空速0.24 h-1、氢气空速1 700 h-1和进料速率5 mL/h(氢腈物质量比约为41)反应条件下,采用固定床反应器考察了不同助剂改性的负载型镍基催化剂上己二腈选择加氢制备6-氨基己腈的反应性能。结果表明,适量的K2O和La2O3助剂的加入,不仅提高了镍基催化剂对6-氨基己腈选择性,而且提高了加氢反应的稳定性。热失重(TG),能量分析光谱(EDX)和X射线衍射(XRD)分析表明,催化剂表面含C和N有机物种的沉积是催化剂失活的主要原因,Ni晶粒的长大也是失活原因之一。采用器内直接H2还原、器外乙醇洗涤和二次焙烧还原对失活催化剂进行再生,可在一定程度上恢复催化剂的活性以及对6-氨基己腈的选择性,其中采用原位H2还原的方式进行再生较为适宜。更多还原

【Abstract】 The catalytic performance of the supported nickel-based catalysts in the catalytic selective hydrogenation of adiponitrile to aminocapronitrile were investigated in a fixed bed reactor with ethanol as solvent and under the reaction conditions of atmosphere pressure,180 ℃,adiponitrile space velocity of 0.24 h-1 and hydrogen space velocity of 1 700 h-1,feed flow of 5 mL/h(hydrogen/adiponitrile molar ratio of 41).It was found that K2O and La2O3 promoters enhanced both 6-Aminocapronitrile selectivity and catalysts stability.There was a trend of catalyst deactivation for every catalyst during hydrogenation reaction,and the catalysts before and after reaction were characterized by means of thermogravimetry(TG),energy dispersive spectrometry(EDX) and x-ray diffraction(XRD).The results indicated that the catalyst deactivation could be mainly ascribed to the surface coverage of some organic species including of C and N.Additionally,the increase of the nickel particles size could also result in the catalyst deactivation to some extent.And the proper regeneration method of deactivated catalyst was reduced by H2 in situ.更多还原