TY - JOUR
T1 -
ZrO
2
support imparts superior activity and stability of Co catalysts for CO
2
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
PY - 2018/1/1
Y1 - 2018/1/1
N2 -
Screening of various supports reveals that Co catalysts supported on ZrO
2
and Al
2
O
3
show good initial activity for CO
2
methanation. Co/ZrO
2
and Co/Al
2
O
3
catalysts prepared by impregnation with different metal loadings were further examined comparatively. The 10Co/ZrO
2
catalyst showed high activity with CO
2
conversion of 92.5% and CH
4
selectivity of 99.9% without deactivation after 300 h time on stream (TOS). However, the 10Co/Al
2
O
3
catalyst gave a lower CO
2
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), H
2
-TPR(temperature programmed reduction), XPS (X-ray photoelectron spectroscopy), chemisorption of H
2
, CO, CH
4
, CO
2
and NH
3
-TPD (temperature programmed desorption). Re-dispersion of Co species on the ZrO
2
support during reduction by H
2
was observed by STEM/EDS. New Co-Zr phase formed on the Co-ZrO
2
interface was directly observed by TEM for the first time; the Co/ZrO
2
catalyst exhibited high stability with high activity for CO
2
conversion. In situ XRD, H
2
-TPR and XPS results indicate the promoting effect of ZrO
2
on the reduction of Co
3
O
4
to Co metal along with the negative effect of Al
2
O
3
. The oxygen vacancies on the ZrO
2
detected by XPS may help to activate CO
2
and H
2
O and resist deactivation. Co/Al
2
O
3
catalyst deactivates rapidly due to coke deposition and spinel formation.
AB -
Screening of various supports reveals that Co catalysts supported on ZrO
2
and Al
2
O
3
show good initial activity for CO
2
methanation. Co/ZrO
2
and Co/Al
2
O
3
catalysts prepared by impregnation with different metal loadings were further examined comparatively. The 10Co/ZrO
2
catalyst showed high activity with CO
2
conversion of 92.5% and CH
4
selectivity of 99.9% without deactivation after 300 h time on stream (TOS). However, the 10Co/Al
2
O
3
catalyst gave a lower CO
2
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), H
2
-TPR(temperature programmed reduction), XPS (X-ray photoelectron spectroscopy), chemisorption of H
2
, CO, CH
4
, CO
2
and NH
3
-TPD (temperature programmed desorption). Re-dispersion of Co species on the ZrO
2
support during reduction by H
2
was observed by STEM/EDS. New Co-Zr phase formed on the Co-ZrO
2
interface was directly observed by TEM for the first time; the Co/ZrO
2
catalyst exhibited high stability with high activity for CO
2
conversion. In situ XRD, H
2
-TPR and XPS results indicate the promoting effect of ZrO
2
on the reduction of Co
3
O
4
to Co metal along with the negative effect of Al
2
O
3
. The oxygen vacancies on the ZrO
2
detected by XPS may help to activate CO
2
and H
2
O and resist deactivation. Co/Al
2
O
3
catalyst deactivates rapidly due to coke deposition and spinel formation.
UR - http://www.scopus.com/inward/record.url?scp=85028404855&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85028404855&partnerID=8YFLogxK
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 -