Catalytic conversion of biomass-derived levulinic acid into γ-valerolactone using iridium nanoparticles supported on carbon nanotubes

A new method has been developed for the catalytic conversion of biomass-derived levulinic acid (LA) into gamma-valerolactone (GVL) with molecular hydrogen (H-2) using a series of heterogeneous noble metal catalysts. Excellent yields of the GVL were obtained under mild reaction conditions of 50 degrees C and 2 MPa of H-2 using iridium nanoparticles supported on carbon nanotubes (Ir/CNT). It is noteworthy that the reaction proceeded smoothly in the presence of formic acid (FA, co-produced with LA in equimolar amounts during the acid-mediated hydrolysis of lignocellulosic biomass). Furthermore, the FA remained intact, highlighting the practical advantages of this process for the convenient and cost-effective processing of a biomass-derived LA/FA solution. The method is effective for the simultaneous production of GVL and FA from a wide variety of renewable biomass resources. (C) 2013, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.