Marella Ravi Kumar, Madduluri Venkata Rao, Lakkaboyana Sivarama Krishna, Hanafiah Marlia M, Yaaratha Sarala
Department of Chemistry (H & S), PACE Institute of Technology & Sciences Ongole 523001 Andhra Pradesh India
Department of Chemical Engineering, University of Cape Town Rondebosch 7701 Western Cape South Africa.
RSC Adv. 2020 Oct 22;10(64):38755-38766. doi: 10.1039/d0ra06003h. eCollection 2020 Oct 21.
Direct catalytic coupling of nitrobenzene hydrogenation and cyclohexanol dehydrogenation was studied in the gas phase over mesoporous MgO-SBA15 supported Cu nanoparticles. This approach avoids an external supply of H and utilizes the liberated H from the dehydrogenation step of the first reactant for the hydrogenation reaction of the second reactant. A catalyst series consisting of four Cu/MgO-SBA15 mesoporous solids with varying Cu loadings (5-20 wt%) were prepared and systematically characterized by BET, ICP, XRD, TPR, TPD, FT-IR, SEM, XPS, and TEM. Among the series, the 15 wt% Cu catalyst exhibited the best performance with ≥82% conversion of nitrobenzene along with ≥89% cyclohexanol conversion. In addition, significantly higher yields of cyclohexanone (83%) and aniline (75%) could be achieved successfully over the same catalyst. Furthermore, the catalyst exhibited almost stable activity during 30 h time-on-stream with slow deactivation. The highly ordered mesoporous silica increases the metal-support interaction with smaller particles of Cu on the surface, and the synergism between acid-base sites is responsible for the improved catalytic activity.
研究了在介孔MgO-SBA15负载的铜纳米颗粒上进行的硝基苯加氢和环己醇脱氢的直接催化偶联反应。该方法避免了外部氢气供应，并利用第一种反应物脱氢步骤中释放的氢气用于第二种反应物的加氢反应。制备了由四种具有不同铜负载量（5-20 wt%）的Cu/MgO-SBA15介孔固体组成的催化剂系列，并通过BET、ICP、XRD、TPR、TPD、FT-IR、SEM、XPS和TEM进行了系统表征。在该系列中，15 wt%的铜催化剂表现出最佳性能，硝基苯转化率≥82%，环己醇转化率≥89%。此外，在同一催化剂上可以成功获得显著更高的环己酮产率（83%）和苯胺产率（75%）。此外，该催化剂在30小时的连续运行期间表现出几乎稳定的活性，失活缓慢。高度有序的介孔二氧化硅增加了与表面较小铜颗粒的金属-载体相互作用，酸碱位点之间的协同作用是催化活性提高的原因。
