Aqueous phase hydrogenation of furfural to furfuryl alcohol over Pd-Cu catalysts

A series of Pd, Cu and bimetallic Pd-Cu catalysts with different metals loadings on various supports were prepared for the selective hydrogenation of furfural to furfuryl alcohol in water as a solvent. In the literature are almost missing the data about the selective hydrogenation of furfural in water. Among the catalysts screened, bimetallic Pd-Cu catalysts supported on MgO and Mg(OH)(2) prepared by electroless plating method showed the highest conversion and selectivity to furfuryl alcohol. The catalysts 5% Pd-5% Cu supported on MgO or Mg(OH)(2) exhibited at 110 degrees C and 0.6 MPa of hydrogen complete conversion of furfural and higher than 98% selectivity toward furfuryl alcohol after 80 min of reaction. The complete conversion of furfural and the same selectivity could be achieved after five catalytic cycles without extra catalyst treatment or reactivation. Based on physico-chemical characterization the role of Cu loading on the performance of bimetallic Pd Cu catalysts was discussed. We assume that over Pd-Cu catalyst prepared by electroless plating method on the surface are present monometallic Pd sites and closely interacting bimetallic Pd-0-Cu2O catalytic sites. The Cu+ sites participate on activation of C=O group in furfural. The interaction between active metal species and the support also influence the performance of catalyst. (C) 2015 Elsevier B.V. All rights reserved.