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Decisive role of Cu/Co interfaces in copper cobaltite derivatives for high performance CO2 methanation catalyst.

Authors :
Varga, Gábor
Szenti, Imre
Kiss, János
Baán, Kornélia
Halasi, Gyula
Óvári, László
Szamosvölgyi, Ákos
Mucsi, Róbert
Dodony, Erzsébet
Fogarassy, Zsolt
Pécz, Béla
Olivi, Luca
Sápi, András
Kukovecz, Ákos
Kónya, Zoltán
Source :
Journal of CO2 Utilization; Sep2023, Vol. 75, pN.PAG-N.PAG, 1p
Publication Year :
2023

Abstract

Thermo-catalytic bio-SNG (CH 4) production is one of the useful tools for converting waste to gaseous fuels through CO 2 conversion. To abundant properly, however, efficient, robust and cost-effective catalysts would be required. Bimetallic systems based on transition metals seem to be promising candidates for this task. The CoCu bimetallic system with in-situ generated interfaces was synthesized and used as a catalyst for CO 2 methanation. The in-depth analysis of the structure-activity-selectivity relationships involving XRD, (NAP-)XPS, EXAFS and TEM-EDX revealed that the co-existence of Co<superscript>0</superscript>, CoO, and Cu<superscript>0</superscript> in the proper distribution on the surface can ensure the selective production of methane. To fine-tune the surface composition of the bimetallic systems, a systematic alteration of the Cu:Co ratio in the precursor spinel structures must be performed. Cu 0.4 Co 2.6 O 4 derivative, stabilizing subsurface Cu(I)–O specimen, showed the best performance with high activity (12,800 nmol g<superscript>–1</superscript> s<superscript>–1</superscript>) and a remarkable selectivity of 65–85% for methane in a wide temperature range (250–425 °C). In studying the mechanistic aspects of methanation, it has been shown that the hydrogenation of active carbon at the surface or below the surface is the key step for the production of methane. So far, this cobalt-catalyzed sub-step has been proposed in catalytic Fischer-Tropsch syntheses. [Display omitted] • Copper cobaltites are useful precursors for the construction of efficient Cu/Co bimetallic catalysts for CO 2 methanation. • The copper-to-cobalt ratios in the octahedral lattice positions of the spinels determined the catalytic performance. • The Cu 0.4 Co 2.6 O 4 derivative with a Co-enriched surface shows high performance producing CH 4 over a wide temperature range. • The hydrogenation of active carbon at the surface or below the surface is the key step for the production of methane. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
22129820
Volume :
75
Database :
Supplemental Index
Journal :
Journal of CO2 Utilization
Publication Type :
Academic Journal
Accession number :
172445971
Full Text :
https://doi.org/10.1016/j.jcou.2023.102582