TY - JOUR
T1 - Mechanisms for High Selectivity in the Hydrodeoxygenation of 5-Hydroxymethylfurfural over PtCo Nanocrystals
AU - Luo, Jing
AU - Yun, Hongseok
AU - Mironenko, Alexander V.
AU - Goulas, Konstantinos
AU - Lee, Jennifer D.
AU - Monai, Matteo
AU - Wang, Cong
AU - Vorotnikov, Vassili
AU - Murray, Christopher B.
AU - Vlachos, Dionisios G.
AU - Fornasiero, Paolo
AU - Gorte, Raymond J.
N1 - Funding Information:
We acknowledge support from the Catalysis Center for Energy Innovation, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award no. DE-SC0001004 and useful discussions with Professor Ayman Karim.
Publisher Copyright:
© 2016 American Chemical Society.
PY - 2016/7/1
Y1 - 2016/7/1
N2 - Carbon-supported, Pt and PtCo nanocrystals (NCs) with controlled size and composition were synthesized and examined for hydrodeoxygenation (HDO) of 5-hydroxymethylfurfural (HMF). Experiments in a continuous flow reactor with 1-propanol solvent, at 120 to 160 °C and 33 bar H2, demonstrated that reaction is sequential on both Pt and PtCo alloys, with 2,5-dimethylfuran (DMF) formed as an intermediate product. However, the reaction of DMF is greatly suppressed on the alloys, such that a Pt3Co2 catalyst achieved DMF yields as high as 98%. XRD and XAS data indicate that the Pt3Co2 catalyst consists of a Pt-rich core and a Co oxide surface monolayer whose structure differs substantially from that of bulk Co oxide. Density functional theory (DFT) calculations reveal that the oxide monolayer interacts weakly with the furan ring to prevent side reactions, including overhydrogenation and ring opening, while providing sites for effective HDO to the desired product, DMF. We demonstrate that control over metal nanoparticle size and composition, along with operating conditions, is crucial to achieving good performance and stability. Implications of this mechanism for other reactions and catalysts are discussed.
AB - Carbon-supported, Pt and PtCo nanocrystals (NCs) with controlled size and composition were synthesized and examined for hydrodeoxygenation (HDO) of 5-hydroxymethylfurfural (HMF). Experiments in a continuous flow reactor with 1-propanol solvent, at 120 to 160 °C and 33 bar H2, demonstrated that reaction is sequential on both Pt and PtCo alloys, with 2,5-dimethylfuran (DMF) formed as an intermediate product. However, the reaction of DMF is greatly suppressed on the alloys, such that a Pt3Co2 catalyst achieved DMF yields as high as 98%. XRD and XAS data indicate that the Pt3Co2 catalyst consists of a Pt-rich core and a Co oxide surface monolayer whose structure differs substantially from that of bulk Co oxide. Density functional theory (DFT) calculations reveal that the oxide monolayer interacts weakly with the furan ring to prevent side reactions, including overhydrogenation and ring opening, while providing sites for effective HDO to the desired product, DMF. We demonstrate that control over metal nanoparticle size and composition, along with operating conditions, is crucial to achieving good performance and stability. Implications of this mechanism for other reactions and catalysts are discussed.
KW - 2,5-dimethyl furan
KW - 5-hydroxymethylfurfural
KW - bimetallic catalyst
KW - hydrodeoxygenation
KW - PtCo nanocrystal
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U2 - 10.1021/acscatal.6b00750
DO - 10.1021/acscatal.6b00750
M3 - Article
AN - SCOPUS:84977126161
VL - 6
SP - 4095
EP - 4104
JO - ACS Catalysis
JF - ACS Catalysis
SN - 2155-5435
IS - 7
ER -