【摘要】 采用化学还原法制备了不同Sn/Pd摩尔比的碳纳米管(CNTs)负载Pd/SnO2催化剂,并将该催化剂用于邻氯硝基苯(o-CNB)的选择加氢反应.采用透射电镜、X射线衍射和电感耦合等离子体技术对所制备的Pd/SnO2/CNTs催化剂进行了表征.结果表明,Sn/Pd摩尔比对该催化剂的邻氯硝基苯选择加氢反应性能影响显著.当Sn/Pd摩尔比为11时,催化剂的活性最高,在常压,60oC反应60min,o-CNB转化率为96%.该催化剂还具有高的邻氯苯胺(o-CAN)选择性,o-CNB转化率达到100%时,脱氯副产物苯胺选择性小于5%.在相同条件下,浸渍法制备的2.4%Pd/CNTs催化剂上脱氯副反应严重,当o-CNB完全转化时,o-CAN选择性只有22%,副产物苯胺选择性则高达78%.更多还原

【Abstract】 Carbon nanotubes(CNTs)-supported Pd/SnO2 catalysts with different Sn/Pd molar ratios were prepared by the chemical reduction method,and their catalytic activity was tested using ortho-chloronitrobenzene(o-CNB)hydrogenation as a probe reaction.The as-made Pd/SnO2/CNTs catalysts were characterized by transmission electron microscopy,X-ray diffraction,and inductively coupled plasma tech-niques.The results show that the catalytic performance of Pd/SnO2/CNTs is greatly affected by the Sn/Pd molar ratio.When the Sn/Pd molar ratio is 11,the Pd/SnO2/CNTs catalyst exhibits the highest activity with 96% conversion of o-CNB at 0.1 MPa and 60 oC in 60 min.More-over,the Pd/SnO2/CNTs catalysts show very good ortho-chloroaniline(o-CAN)selectivity,evidenced by the fact that the selectivity for by-product aniline is less than 5% when the conversion of o-CNB is 100%.For the 2.4% Pd/CNTs catalyst prepared by impregnation,under the identical conditions,the selectivity for o-CAN is only 22% when the o-CNB conversion is 100%.更多还原