氧化铝负载镍催化剂催化丙酮胺化选择性合成异丙胺

通过XRD、XRF和BET分析表征浙江省低碳脂肪胺工程技术研究中心提供的氧化铝负载镍催化剂a和催化剂b的结构,将催化剂用于催化丙酮胺化反应合成异丙胺,考察原料配比、反应温度、反应压力和丙酮空速对合成异丙胺反应的影响。结果表明,催化剂的比表面积和装填方式影响催化剂活性。丙酮胺化合成异丙胺的最佳合成条件为:反应压力(0.3~0.4)MPa,反应温度(383.15~393.15)K,n(丙酮)∶n(氨气)∶n(氢气)=1∶3∶(3~4),空速(0.30~0.35)h-1,在最佳条件下,异丙胺选择性100%,异丙胺产率最高达97.22%,催化剂连续使用4个月仍保持较好的催化活性。氧化铝负载镍催化剂上丙酮胺化反应机理主要是加成-消除-还原反应机理,而还原-取代反应机理是次要形式。

Selective synthesis of isopropylamine by catalytic reductive amination of acetone over Ni/Al2 O3 catalysts

Ni/Al₂O₃ catalysts a and b provided by The Low Carbon Fatty Amine Engineering Research Center of Zhejiang Province were characterized by XRD,XRF and BET,and were used to catalyze the amination of acetone to isopropylamine.The effects of raw material molar ratios,reaction temperatures,reaction pressure and acetone space velocity were investigated.The experimental results showed that the specific surface area and loading mode of the catalysts had an influence on the activities of the catalysts for acetone amination.The optimal reaction condition of acetone amination to isopropylamine was as follows: reaction pressure （0.3-0.4） MPa,reaction temperature （383.15-393.15） K,n（acetone）∶n（ammonia）∶n（hydrogen）=1∶3∶（3-4）,and acetone liquid space velocity （0.30-0.35） h^-1 .Under the optimal reaction condition,the selectivity to and the maximum yield of isopropylamine were 100% and 97.22%,respectively.The catalysts maintained excellent catalytic activity after the continuous running for 4 months.The mechanism for amination reaction of acetone over Ni/Al₂O₃ catalyst was mainly addition-elimination-reduction mechanism,and its secondary form was reduction-substitution mechanism.