Promotional action of Cu in Rh-Cu/activated carbon catalyst for selective hydrogenation of para-chloronitrobenzene to para-chloroaniline

Department of Chemistry, Sidho-Kanho-Birsha University, Purulia-723 104, West Bengal, India E-mail: nmahata@hotmail.com Manuscript received 27 July 2018, accepted 08 August 2018 Hydrogenation of para-chloronitrobenzene was studied over Cu promoted Rh catalyst supported on activated carbon in liquid phase under 1.5 MPa hydrogen pressure at 393 K. Methanol has been used as solvent. The bimetallic RhCu catalysts exhi­bited performance much superior to the monometallic Rh catalysts, particularly in terms of para-chloroaniline selectivity and catalyst stability. Physico-chemical techniques like N2 adsorption, H2 chemisorption, transmission electron microscopy (TEM) were applied to characterise the catalysts. Catalytic performance (activity and selectivity) was correlated to the surface struc­ture. Cu islands on Rh surface activate N=O bonds of para-chloronitrobenzene, which thereby undergoes facile hydrogena­tion leading to exclusive formation of para-chloroaniline