TY - JOUR
T1 - ZrO2 support imparts superior activity and stability of Co catalysts for CO2 methanation
AU - Li, Wenhui
AU - Nie, Xiaowa
AU - Jiang, Xiao
AU - Zhang, Anfeng
AU - Ding, Fanshu
AU - Liu, Min
AU - Liu, Zhongmin
AU - Guo, Xinwen
AU - Song, Chunshan
N1 - Funding Information:
This work was financially supported in part by the National Natural Science Foundation of China (No. 21503027 and No. 21503029 ), the Fundamental Research Funds for the Central Universities (No. DUT15RC(3)027 and No. DUT15ZD236), the National Key Research and Development Program of China ( 2016YFB0600902-5 ), the QianRen Program of China and the Pennsylvania State University. The STEM/EDS and TEM were performed at the Materials Characterization Laboratory of the Pennsylvania State University, for which the assistance of Jennifer Gray is gratefully acknowledged.
Publisher Copyright:
© 2017
PY - 2018/1
Y1 - 2018/1
N2 - Screening of various supports reveals that Co catalysts supported on ZrO2 and Al2O3 show good initial activity for CO2 methanation. Co/ZrO2 and Co/Al2O3 catalysts prepared by impregnation with different metal loadings were further examined comparatively. The 10Co/ZrO2 catalyst showed high activity with CO2 conversion of 92.5% and CH4 selectivity of 99.9% without deactivation after 300 h time on stream (TOS). However, the 10Co/Al2O3 catalyst gave a lower CO2 conversion of 77.8% which decreased to 38.6% after 300 h TOS. The catalysts were characterized by STEM/EDS (scanning transmission electron microscopy/energy-dispersive X-ray spectroscopy), in situ XRD(X-ray diffractometer), H2-TPR(temperature programmed reduction), XPS (X-ray photoelectron spectroscopy), chemisorption of H2, CO, CH4, CO2 and NH3-TPD (temperature programmed desorption). Re-dispersion of Co species on the ZrO2 support during reduction by H2 was observed by STEM/EDS. New Co-Zr phase formed on the Co-ZrO2 interface was directly observed by TEM for the first time; the Co/ZrO2 catalyst exhibited high stability with high activity for CO2 conversion. In situ XRD, H2-TPR and XPS results indicate the promoting effect of ZrO2 on the reduction of Co3O4 to Co metal along with the negative effect of Al2O3. The oxygen vacancies on the ZrO2 detected by XPS may help to activate CO2 and H2O and resist deactivation. Co/Al2O3 catalyst deactivates rapidly due to coke deposition and spinel formation.
AB - Screening of various supports reveals that Co catalysts supported on ZrO2 and Al2O3 show good initial activity for CO2 methanation. Co/ZrO2 and Co/Al2O3 catalysts prepared by impregnation with different metal loadings were further examined comparatively. The 10Co/ZrO2 catalyst showed high activity with CO2 conversion of 92.5% and CH4 selectivity of 99.9% without deactivation after 300 h time on stream (TOS). However, the 10Co/Al2O3 catalyst gave a lower CO2 conversion of 77.8% which decreased to 38.6% after 300 h TOS. The catalysts were characterized by STEM/EDS (scanning transmission electron microscopy/energy-dispersive X-ray spectroscopy), in situ XRD(X-ray diffractometer), H2-TPR(temperature programmed reduction), XPS (X-ray photoelectron spectroscopy), chemisorption of H2, CO, CH4, CO2 and NH3-TPD (temperature programmed desorption). Re-dispersion of Co species on the ZrO2 support during reduction by H2 was observed by STEM/EDS. New Co-Zr phase formed on the Co-ZrO2 interface was directly observed by TEM for the first time; the Co/ZrO2 catalyst exhibited high stability with high activity for CO2 conversion. In situ XRD, H2-TPR and XPS results indicate the promoting effect of ZrO2 on the reduction of Co3O4 to Co metal along with the negative effect of Al2O3. The oxygen vacancies on the ZrO2 detected by XPS may help to activate CO2 and H2O and resist deactivation. Co/Al2O3 catalyst deactivates rapidly due to coke deposition and spinel formation.
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U2 - 10.1016/j.apcatb.2017.08.048
DO - 10.1016/j.apcatb.2017.08.048
M3 - Article
AN - SCOPUS:85028404855
VL - 220
SP - 397
EP - 408
JO - Applied Catalysis B: Environmental
JF - Applied Catalysis B: Environmental
SN - 0926-3373
ER -