TY - JOUR
T1 - Ruthenium-catalyzed hydrogenation of levulinic acid
T2 - Influence of the support and solvent on catalyst selectivity and stability
AU - Luo, Wenhao
AU - Deka, Upakul
AU - Beale, Andrew M.
AU - van Eck, Ernst R. H.
AU - Bruijnincx, Pieter C. A.
AU - Weckhuysen, Bert M.
PY - 2013/5
Y1 - 2013/5
N2 - The catalytic performance of 1 wt% Ru-based catalysts in the hydrogenation of levulinic acid (LA) has been studied at 40 bar H-2 and 473 K. This was done by assessing the influence of the support acidity (i.e., Nb2O5, TiO2, H-beta, and H-ZSM5) and solvent (i.e., dioxane, 2-ethylhexanoic acid (EHA), and neat LA). The Ru/TiO2 gave excellent selectivity to gamma-valerolactone (GVL) (97.5%) at 100% conversion and was remarkably stable even under severe reaction conditions. Ru/H-ZSM5 showed a 45.8% yield of pentanoic acid (PA) and its esters in dioxane, which is the first example of this one-pot conversion directly from LA at 473 K. The gradual deactivation of zeolite-supported catalysts in EHA and neat LA was mainly caused by dealumination, as confirmed by Al-27 MAS NMR. Coke buildup originated from angelicalactone and, remarkably, occurred preferentially in the zigzag channels of H-ZSM5 as shown by systematic shifts in the XRD patterns. The GVL ring-opening step is considered to be the rate-determining step on the pathway to PA, necessitating an acidic support. (C) 2013 Elsevier Inc. All rights reserved.
AB - The catalytic performance of 1 wt% Ru-based catalysts in the hydrogenation of levulinic acid (LA) has been studied at 40 bar H-2 and 473 K. This was done by assessing the influence of the support acidity (i.e., Nb2O5, TiO2, H-beta, and H-ZSM5) and solvent (i.e., dioxane, 2-ethylhexanoic acid (EHA), and neat LA). The Ru/TiO2 gave excellent selectivity to gamma-valerolactone (GVL) (97.5%) at 100% conversion and was remarkably stable even under severe reaction conditions. Ru/H-ZSM5 showed a 45.8% yield of pentanoic acid (PA) and its esters in dioxane, which is the first example of this one-pot conversion directly from LA at 473 K. The gradual deactivation of zeolite-supported catalysts in EHA and neat LA was mainly caused by dealumination, as confirmed by Al-27 MAS NMR. Coke buildup originated from angelicalactone and, remarkably, occurred preferentially in the zigzag channels of H-ZSM5 as shown by systematic shifts in the XRD patterns. The GVL ring-opening step is considered to be the rate-determining step on the pathway to PA, necessitating an acidic support. (C) 2013 Elsevier Inc. All rights reserved.
KW - Deactivation
KW - Dealumination
KW - Levulinic acid
KW - Pentanoic acid
KW - Ruthenium
KW - Zeolites
U2 - 10.1016/j.jcat.2013.02.003
DO - 10.1016/j.jcat.2013.02.003
M3 - Article
SN - 0021-9517
VL - 301
SP - 175
EP - 186
JO - Journal of Catalysis
JF - Journal of Catalysis
ER -