Karanwal, Neha Verma, Deepak Butolia, Paresh Kim, Seung Min Kim, Jaehoon 2024-01-19T18:03:36Z 2024-01-19T18:03:36Z 2021-09-04 2020-02-07 1463-9262 https://pubs.kist.re.kr/handle/201004/118964 The direct conversion of levulinic acid (LA) to valeric biofuel is highly promising for the development of biorefineries. Herein, LA is converted into valeric acid (VA) via one-pot direct cascade conversion over non-noble metal-based Nb-doped Cu on Zr-doped porous silica (Nb-Cu/ZPS). Under mild reaction conditions (150 degrees C and 3.0 MPa H-2 for 4 h), LA was completely converted into VA in high yield (99.8%) in aqueous medium with a high turnover frequency of 0.038 h(-1). The Lewis acid sites of ZPS enhanced the adsorption of LA on the catalyst surface, and both the Lewis and BrOnsted acidity associated with Nb2O5 and the metallic Cu-0 sites promoted catalysis of the cascade hydrogenation, ring cyclization, ring-opening, and hydrogenation reactions to produce VA from LA. The bimetallic Nb-Cu/ZPS catalyst was also effective for the conversion of VA into various valeric esters in C1-C5 alcohol media. The presence of Nb2O5 effectively suppressed metal leaching and coke formation, which are serious issues in the liquid-phase conversion of highly acidic LA during the reaction. The catalyst could be used for up to five consecutive cycles with marginal loss of activity, even without catalyst re-activation. English ROYAL SOC CHEMISTRY GAMMA-VALEROLACTONE SELECTIVE HYDROGENATION NIOBIUM OXIDE PENTANOIC ACID FORMIC-ACID BIOMASS HYDROGENOLYSIS ESTERS CO HYDRODEOXYGENATION One-pot direct conversion of levulinic acid into high-yield valeric acid over a highly stable bimetallic Nb-Cu/Zr-doped porous silica catalyst Article 10.1039/c9gc03516h 1 GREEN CHEMISTRY, v.22, no.3, pp.766 - 787 GREEN CHEMISTRY 22 3 766 787 scie scopus 000523465000015 2-s2.0-85079647119 Chemistry, Multidisciplinary Green & Sustainable Science & Technology Chemistry Science & Technology - Other Topics Article GAMMA-VALEROLACTONE SELECTIVE HYDROGENATION NIOBIUM OXIDE PENTANOIC ACID FORMIC-ACID BIOMASS HYDROGENOLYSIS ESTERS CO HYDRODEOXYGENATION