TY - JOUR
T1 - Structural evolution of ZIF-67-derived catalysts for furfural hydrogenation
AU - Lee, Jun Gyeong
AU - Yoon, Sinmyung
AU - Yang, Euiseob
AU - Lee, Jae Hwa
AU - Song, Kyung
AU - Moon, Hoi Ri
AU - An, Kwangjin
N1 - Funding Information:
This research was supported by Basic Science Research Program (2018R1A1A1A05079555), Technology Development Program to Solve Climate Changes (2017M1A2A2087630), and the Engineering Research Center of Excellence Program (2020R1A5A1019631) of the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT, and the Technology Innovation Program (20012971, 20010853) by the Ministry of Trade, Industry & Energy (MOTIE), and UNIST (1.200035.01). We acknowledge Suhye Park in Namotec for technical support in in situ TEM study. H.R.M. acknowledges the support from NRF funded by the Ministry of Science and ICT (NRF-2016R1A5A1009405). K.S. acknowledges the support from the Korean government (MSIT) (Grants No. NRF-2018R1A2B6008258) and the Fundamental Research Program of the Korea Institute of Materials Science (KIMS) (Grant No. PNK7070).
Publisher Copyright:
© 2020 Elsevier Inc.
PY - 2020/12
Y1 - 2020/12
N2 - Zeolitic imidazolate framework-67 (ZIF-67) can be converted to metallic Co nanoparticles supported on N-doped carbon (Co/NC) through reduction. However, its unique properties, including extremely high surface area, isoreticular pore structure, and regular metal–organic network, disappear after high-temperature (>500 °C) reduction. Aggregated CoOx particles reduce the number of surface-active sites, resulting in poor catalytic activity. If the original ZIF-67 structure is maintained after the high-temperature reduction, promoting the uniform distribution of active sites in the porous carbon, the catalytic performance can be further improved. Herein, the correlation between the catalytic furfural hydrogenation performance, Co/NC morphology, and oxidation state of Co was investigated as a function of the H2 reduction temperature and time. The reduction of ZIF-67 at 400 °C for 6 h yields a highly dispersed Co/NC catalyst, while preserving the overall morphology. The resulting Co/NC-400-6 catalyst exhibits the highest activity, promoting high selectivity toward 2-methylfuran. The product selectivity can be further altered by incorporating Cu into ZIF-67 to produce furfuryl alcohol. With proper H2 treatment to minimize the damage to the intrinsic surface area and pore structure, metal–organic frameworks can be utilized as high-performance heterogeneous catalysts by maximizing the distribution of active sites.
AB - Zeolitic imidazolate framework-67 (ZIF-67) can be converted to metallic Co nanoparticles supported on N-doped carbon (Co/NC) through reduction. However, its unique properties, including extremely high surface area, isoreticular pore structure, and regular metal–organic network, disappear after high-temperature (>500 °C) reduction. Aggregated CoOx particles reduce the number of surface-active sites, resulting in poor catalytic activity. If the original ZIF-67 structure is maintained after the high-temperature reduction, promoting the uniform distribution of active sites in the porous carbon, the catalytic performance can be further improved. Herein, the correlation between the catalytic furfural hydrogenation performance, Co/NC morphology, and oxidation state of Co was investigated as a function of the H2 reduction temperature and time. The reduction of ZIF-67 at 400 °C for 6 h yields a highly dispersed Co/NC catalyst, while preserving the overall morphology. The resulting Co/NC-400-6 catalyst exhibits the highest activity, promoting high selectivity toward 2-methylfuran. The product selectivity can be further altered by incorporating Cu into ZIF-67 to produce furfuryl alcohol. With proper H2 treatment to minimize the damage to the intrinsic surface area and pore structure, metal–organic frameworks can be utilized as high-performance heterogeneous catalysts by maximizing the distribution of active sites.
KW - Catalyst
KW - Furfural hydrogenation
KW - In situ characterization
KW - Metal-organic framework (MOF)
KW - Zeolitic imidazolate framework-67 (ZIF-67)
UR - http://www.scopus.com/inward/record.url?scp=85096176242&partnerID=8YFLogxK
U2 - 10.1016/j.jcat.2020.10.014
DO - 10.1016/j.jcat.2020.10.014
M3 - Article
AN - SCOPUS:85096176242
SN - 0021-9517
VL - 392
SP - 302
EP - 312
JO - Journal of Catalysis
JF - Journal of Catalysis
ER -