TY - JOUR
T1 - Structure-dependent activity of CeO2 supported Ru catalysts for CO2 methanation
AU - Sakpal, Tushar
AU - Lefferts, Leon
N1 - Elsevier deal
PY - 2018/11/1
Y1 - 2018/11/1
N2 - In this study, CeO2 rods (CeO2/r), cubes (CeO2/c) and octahedra (CeO2/o) supported catalysts with identical Ru particle size were prepared. Trend in the activity of these catalysts for CO2 methanation was compared with the trend in their oxygen vacancy concentration measured after calcination. Ru/CeO2/r outperforms the other two catalysts with a reaction rate of 11.0 × 10−8 mols-1mRu
-2 and selectivity to methane of 99% at 250 °C. Temperature-programmed reduction (TPR), Raman and X-ray photoemission spectroscopy (XPS) results confirms that Ru addition enhances reduction of CeO2. Also, Ru/CeO2/r is more reducible and contains more oxygen vacancies as compared to Ru/CeO2/o and Ru/CeO2/c, both after calcination as well as under reducing conditions. H2 consumption during TPR shows removal of oxygen equivalent to about 3 monolayers, implying diffusion of vacancies into the subsurface or bulk of CeO2. The catalyst with the highest concentration of oxygen vacancies is also the most active catalyst, suggesting that reactive adsorption CO2 at an oxygen vacancy is the rate determining step.
AB - In this study, CeO2 rods (CeO2/r), cubes (CeO2/c) and octahedra (CeO2/o) supported catalysts with identical Ru particle size were prepared. Trend in the activity of these catalysts for CO2 methanation was compared with the trend in their oxygen vacancy concentration measured after calcination. Ru/CeO2/r outperforms the other two catalysts with a reaction rate of 11.0 × 10−8 mols-1mRu
-2 and selectivity to methane of 99% at 250 °C. Temperature-programmed reduction (TPR), Raman and X-ray photoemission spectroscopy (XPS) results confirms that Ru addition enhances reduction of CeO2. Also, Ru/CeO2/r is more reducible and contains more oxygen vacancies as compared to Ru/CeO2/o and Ru/CeO2/c, both after calcination as well as under reducing conditions. H2 consumption during TPR shows removal of oxygen equivalent to about 3 monolayers, implying diffusion of vacancies into the subsurface or bulk of CeO2. The catalyst with the highest concentration of oxygen vacancies is also the most active catalyst, suggesting that reactive adsorption CO2 at an oxygen vacancy is the rate determining step.
KW - UT-Hybrid-D
KW - CO methanation
KW - Oxygen vacancy concentration
KW - Ru particle size
KW - Structure-activity relationship
KW - CeO nano-shapes
UR - http://www.scopus.com/inward/record.url?scp=85053765164&partnerID=8YFLogxK
U2 - 10.1016/j.jcat.2018.08.027
DO - 10.1016/j.jcat.2018.08.027
M3 - Article
AN - SCOPUS:85053765164
VL - 367
SP - 171
EP - 180
JO - Journal of catalysis
JF - Journal of catalysis
SN - 0021-9517
ER -