TY - JOUR
T1 - Cerium oxide catalysts for oxidative coupling of methane reaction
T2 - Effect of lithium, samarium and lanthanum dopants
AU - Siakavelas, G. I.
AU - Charisiou, N. D.
AU - AlKhoori, A.
AU - Sebastian, V.
AU - Hinder, S. J.
AU - Baker, M. A.
AU - Yentekakis, I. V.
AU - Polychronopoulou, K.
AU - Goula, M. A.
N1 - Funding Information:
NDC, IVY and MAG are grateful for financial support from the European Union and Greek national funds through the operational program Competitiveness, Entrepreneurship and Innovation, under the call Research-Create-Innovate (Project code: T1EDK-00782 ). GIS is grateful for financial support by Greece and ESF through the Operational Programme "Human Resources Development, Education and Lifelong Learning" in the context of the project “Strengthening Human Resources Research Potential via Doctorate Research” ( MIS-5000432 ), implemented by the State Scholarships Foundation (ΙΚΥ). KP and AK acknowledge the financial support from Khalifa University through the CIRA-2020–077 and RC2–2018-024 grants.
Publisher Copyright:
© 2022 Elsevier Ltd
PY - 2022/4
Y1 - 2022/4
N2 - The work presented herein reports on the oxidative coupling of methane (OCM) performance of a series of Li-free and Li-doped CeO2 and CeO2 modified with Sm3+ and La3+ catalysts. The supporting materials (Ce, Sm-Ce and La-Sm-Ce metal oxides) were synthesized using the microwave assisted sol-gel method in order to achieve nanophase complex materials with increased particle surface energy and reactivity. Lithium ions were added, using the wet impregnation technique, in order to further improve the physicochemical characteristics and reinforce the activity and selectivity, in terms of C2H6 and C2H4 production. All materials were characterized using N2 adsorption-desorption, XRD, Raman spectroscopy, CO2-TPD, H2-TPR, SEM and XPS. We showed that the addition of lithium species changed the reaction pathway and drastically enhanced the production of ethylene and ethane, mainly for the promoted catalysts (Li/Sm-Ce and Li/La-Sm-Ce). In particular, the presence and the synergy between the electrophilic oxygen species (peroxide and superoxide), population of oxygen vacancy sites and the surface moderate basic sites determined the reaction pathway and the desirable product distribution.
AB - The work presented herein reports on the oxidative coupling of methane (OCM) performance of a series of Li-free and Li-doped CeO2 and CeO2 modified with Sm3+ and La3+ catalysts. The supporting materials (Ce, Sm-Ce and La-Sm-Ce metal oxides) were synthesized using the microwave assisted sol-gel method in order to achieve nanophase complex materials with increased particle surface energy and reactivity. Lithium ions were added, using the wet impregnation technique, in order to further improve the physicochemical characteristics and reinforce the activity and selectivity, in terms of C2H6 and C2H4 production. All materials were characterized using N2 adsorption-desorption, XRD, Raman spectroscopy, CO2-TPD, H2-TPR, SEM and XPS. We showed that the addition of lithium species changed the reaction pathway and drastically enhanced the production of ethylene and ethane, mainly for the promoted catalysts (Li/Sm-Ce and Li/La-Sm-Ce). In particular, the presence and the synergy between the electrophilic oxygen species (peroxide and superoxide), population of oxygen vacancy sites and the surface moderate basic sites determined the reaction pathway and the desirable product distribution.
KW - C production
KW - Cerium-doped catalysts, Trivalent ions
KW - Electrophilic oxygen species
KW - Oxidative coupling of methane
UR - http://www.scopus.com/inward/record.url?scp=85123777604&partnerID=8YFLogxK
U2 - 10.1016/j.jece.2022.107259
DO - 10.1016/j.jece.2022.107259
M3 - Article
AN - SCOPUS:85123777604
SN - 2213-3437
VL - 10
JO - Journal of Environmental Chemical Engineering
JF - Journal of Environmental Chemical Engineering
IS - 2
M1 - 107259
ER -