MxNi100-x (M = Ag, and Co) nanoparticles supported on CeO2 nanorods derived from Ce-metal organic frameworks as an effective catalyst for reduction of organic pollutants: Langmuir-Hinshelwood kinetics and mechanism

In this study, AgxNi100-x, and CoxNi100-x(x = 0, 20, 40, 60, 80, and 100) bimetallic nanoparticles were successfully decorated on the surface of CeO2 nanorods derived from Ce-metal organic frameworks (Ce-MOF). The as-synthesized products were characterized using different techniques including XRD, FE-SEM, EDX, TEM, ICP, and BET. The as-prepared nanocomposites showed remarkable catalytic activity towards the reduction of organic pollutants such as 4-nitrophenol (4-NP), and rhodamine-B dye (RhB) by NaBH4 solution, with high stability and reusability for five consecutive cycles. The obtained results indicated that among these nanocomposites, Ag80Ni20@CeO2, and Co60Ni40@CeO2 exhibited the best catalytic performance, with high turn over frequency. The adsorption equilibrium constants of borohydride (KBH4-), and 4-nitrophenol ( K4-NP) were determined by the Langmuir-Hinshelwood model, and the reaction mechanism was investigated in detail. The thermodynamic parameters including energy of activation, activation enthalpy, entropy, and Gibbs free energy were calculated, and discussed.