Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros, 3515 Miskolc, Hungary.
Institute of Mineralogy and Geology, University of Miskolc, Miskolc-Egyetemváros, 3515 Miskolc, Hungary.
Int J Mol Sci. 2022 Jun 10;23(12):6535. doi: 10.3390/ijms23126535.
Aniline (AN) is one of the most important compounds in the chemical industry and is prepared by the catalytic hydrogenation of nitrobenzene (NB). The development of novel, multifunctional catalysts which are easily recoverable from the reaction mixture is, therefore, of paramount importance. Compared to conventional filtration, magnetic separation is favored because it is cheaper and more facile. For satisfying these requirements, we developed manganese ferrite (MnFeO)-supported, magnetically separable palladium catalysts with high catalytic activity in the hydrogenation of nitrobenzene to aniline. In addition to high NB conversion and AN yield, remarkable aniline selectivity (above 96 n/n%) was achieved. Surprisingly, the magnetic support alone also shows moderate catalytic activity even without noble metals, and thus, up to 94 n/n% nitrobenzene conversion, along with 47 n/n% aniline yield, are attainable. After adding palladium nanoparticles to the support, the combined catalytic activity of the two nanomaterials yielded a fast, efficient, and highly selective catalyst. During the test of the Pd/MnFeO catalyst in NB hydrogenation, no by-products were detected, and consequently, above 96 n/n% aniline yield and 96 n/n% selectivity were achieved. The activity of the Pd/MnFeO catalyst was not particularly sensitive to the hydrogenation temperature, and reuse tests indicate its applicability in at least four cycles without regeneration. The remarkable catalytic activity and other favorable properties can make our catalyst potentially applicable to both NB hydrogenation and other similar or slightly different reactions.
苯胺（AN）是化学工业中最重要的化合物之一，由硝基苯（NB）催化氢化制备。因此，开发新型多功能催化剂，使其易于从反应混合物中回收，至关重要。与传统过滤相比，磁分离更受欢迎，因为它更便宜、更简单。为了满足这些要求，我们开发了具有高催化活性的负载在锰铁氧体（MnFeO）上的可分离磁性钯催化剂，用于硝基苯加氢制备苯胺。除了高的 NB 转化率和 AN 收率外，还实现了显著的苯胺选择性（高于 96 n/n%）。令人惊讶的是，即使没有贵金属，磁性载体本身也表现出中等的催化活性，因此，最高可达 94 n/n%的硝基苯转化率，以及 47 n/n%的苯胺收率。在向载体中添加钯纳米粒子后，两种纳米材料的协同催化活性产生了一种快速、高效和高选择性的催化剂。在 NB 加氢反应中测试 Pd/MnFeO 催化剂时，未检测到副产物，因此，苯胺的收率和选择性均高于 96 n/n%。Pd/MnFeO 催化剂的活性对加氢温度不特别敏感，重复使用测试表明，在至少四个循环中无需再生即可使用。其显著的催化活性和其他优良性质使我们的催化剂有可能适用于 NB 加氢以及其他类似或略有不同的反应。
