负载型杂多酸催化下N2O5对氯苯的选择性硝化研究

使用负载型杂多酸为催化剂，N2O5为硝化剂的新型硝化体系，对氯苯的硝化反应进行研究。文章分别考察了杂多酸类型、载体种类、杂多酸负载量及催化剂循环使用次数等因素对硝化反应的影响。结果证明，N2O5硝化反应属于酸催化反应，负载型杂多酸能显著提高N2O5的硝化能力；催化剂回收后可直接重复使用，催化活性没有明显的降低。在优化条件下，氯苯硝化反应得率为26%，对位选择性达到68.8%，表明N2O5是一种具有应用前景的硝化试剂，可取代传统的硝硫混酸硝化法，减少废酸处理，符合绿色环保要求。

Investigation on Supported Heteropoly Acids Assisted Selective Nitration of Chlorobenzene with N2O5

Chlorobenzene nitration was carried out using supported heteropoly acids as catalysts and N2O5 as nitrating agent. Many factors were investigated, such as kinds of heteropoly acids and carriers, loading of heteropoly acid, number of use, and so on. Results shows the nitration using N2O5 is an acid catalyzed reaction, the supported heteropoly acids can highly enhance the nitration ability of N2O5; the catalyst can be directly reused after recycle, and its activity is not obviously decreased. In the optimum condition, the yield of nitration is 26%, and para-selectivity is up to 68.8%, which indicates that is N2O5 a prospective nitration agent, it can replace the concentrated mineral acid as the catalyst which is one of the most environmentally harmful processes, and meets the requirement of green environmental protection.