Selective hydrogenation of d-mannose to d-mannitol using NiO-modified TiO2 (NiO-TiO2) supported ruthenium catalyst Original Research Article

NiO-modified TiO2 (NiO-TiO2) supported ruthenium catalyst Ru/(NiO-TiO2) is prepared by simple impregnation method and characterized by using energy dispersive X-ray analysis (EDX/EDS), temperature- programmed reduction (TPR), inductively coupled plasma (ICP) mass spectrometry, transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and CO chemisorption. The catalyst Ru/(NiO-TiO2) is evaluated in d-mannose hydrogenation and hydrogenation experiments to produce a selective product d-mannitol were carried out batch wise in a three-phase laboratory scale reactor. A tentative mechanism for reduction of d-mannose is presented. The kinetics of d-mannose hydrogenation to d-mannitol using catalyst Ru/(NiO-TiO2) was studied. The kinetic data were modeled by zero, first and second-order reaction equations. A set of four experiments was also carried out to test the deactivation of the catalyst. For affording maximum d-mannose conversion, yield and selectivity to d-mannitol, the reaction conditions are optimized.