TY - JOUR
T1 - Guaiacol Hydrodeoxygenation over Iron-Ceria Catalysts with Platinum Single-Atom Alloy Clusters as a Promoter
AU - Li, Congcong
AU - Nakagawa, Yoshinao
AU - Yabushita, Mizuho
AU - Nakayama, Akira
AU - Tomishige, Keiichi
N1 - Funding Information:
The work was supported by JSPS KAKENHI 18H05247 and NEDO Extensive Support for Young Promising Researchers. Congcong Li acknowledges the financial support from the China Scholarship Council. The authors thank the Technical Division in the School of Engineering of Tohoku University for the assistance in TEM measurement. Part of the calculations was performed on supercomputers at RCCS (Okazaki), RIIT (Kyushu Univ.), ACCMS (Kyoto Univ.), and the Center for Comput. Mater. Sci., Institute for Materials Research (Tohoku University, Proposal No. 202012-SCKXX-0012).
Publisher Copyright:
© 2021 American Chemical Society
PY - 2021/10/15
Y1 - 2021/10/15
N2 - A series of ceria-supported Fe catalysts with a trace amount of noble-metal modification (NM-Fe/CeO2, NM = Pt, Ir, Pd, Rh, and Ru) were prepared by the co-impregnation method and used for guaiacol hydrodeoxygenation (HDO) to phenolic compounds at 673 K and atmospheric pressure. In the absence of H2O, the addition of noble metal improved the initial activities but showed severer deactivation than Fe/CeO2. Conversely, the addition of water showed little effect on the initial activity and helped to improve the stability of NM-Fe/CeO2. Among all of the tested NM-Fe/CeO2catalysts, Pt-Fe/CeO2showed the highest guaiacol conversion. The X-ray absorption spectroscopy (XAS) characterization confirmed that the original structure of active FeOxspecies, probably Fe4O6, was mostly preserved after the addition of Pt. The Pt modifier was completely reduced to form Pt1Fe4single-atom alloy (Pt1Fe4SAA) clusters during the guaiacol HDO reaction. These Pt1Fe4SAA clusters probably promoted the reduction of FeOxspecies to form the coordinatively unsaturated sites (CUS), which were the active sites for the HDO reaction. The presence of Pt1Fe4SAA clusters also encouraged the dissociation of H2O on Pt-Fe/CeO2to maintain the catalytic activity under the H2O-containing conditions, as shown by the temperature-programmed surface reaction with H2O (H2O-TPSR). Characterization of spent catalysts with Raman spectroscopy, scanning transition electron microscopy (STEM), and XAS showed that the Pt-Fe/CeO2catalyst was deactivated by coke deposition and carburization of Fe4O6clusters in the absence of H2O, while the growth of coke species and the formation of inactive iron carbide were suppressed in the presence of H2O.
AB - A series of ceria-supported Fe catalysts with a trace amount of noble-metal modification (NM-Fe/CeO2, NM = Pt, Ir, Pd, Rh, and Ru) were prepared by the co-impregnation method and used for guaiacol hydrodeoxygenation (HDO) to phenolic compounds at 673 K and atmospheric pressure. In the absence of H2O, the addition of noble metal improved the initial activities but showed severer deactivation than Fe/CeO2. Conversely, the addition of water showed little effect on the initial activity and helped to improve the stability of NM-Fe/CeO2. Among all of the tested NM-Fe/CeO2catalysts, Pt-Fe/CeO2showed the highest guaiacol conversion. The X-ray absorption spectroscopy (XAS) characterization confirmed that the original structure of active FeOxspecies, probably Fe4O6, was mostly preserved after the addition of Pt. The Pt modifier was completely reduced to form Pt1Fe4single-atom alloy (Pt1Fe4SAA) clusters during the guaiacol HDO reaction. These Pt1Fe4SAA clusters probably promoted the reduction of FeOxspecies to form the coordinatively unsaturated sites (CUS), which were the active sites for the HDO reaction. The presence of Pt1Fe4SAA clusters also encouraged the dissociation of H2O on Pt-Fe/CeO2to maintain the catalytic activity under the H2O-containing conditions, as shown by the temperature-programmed surface reaction with H2O (H2O-TPSR). Characterization of spent catalysts with Raman spectroscopy, scanning transition electron microscopy (STEM), and XAS showed that the Pt-Fe/CeO2catalyst was deactivated by coke deposition and carburization of Fe4O6clusters in the absence of H2O, while the growth of coke species and the formation of inactive iron carbide were suppressed in the presence of H2O.
KW - catalyst deactivation
KW - ceria
KW - guaiacol hydrodeoxygenation
KW - iron oxide
KW - single-atom alloy
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U2 - 10.1021/acscatal.1c03539
DO - 10.1021/acscatal.1c03539
M3 - Article
AN - SCOPUS:85117792089
VL - 11
SP - 12794
EP - 12814
JO - ACS Catalysis
JF - ACS Catalysis
SN - 2155-5435
IS - 20
ER -