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Alkaline zirconates as effective materials for hydrogen production through consecutive carbon dioxide capture and conversion in methane dry reforming
[Display omitted] •Alkaline zirconates work as bifunctional materials: CO2 sorbent and catalytic material in MDR.•Saturated CO2 gas flow only allows obtaining H2 through POM reaction at T > 750 °C.•High H2 production was achieved, using carbonated-ceramics under CO-O2 gas mixture.•High regenerati...
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Published in: | Applied catalysis. B, Environmental Environmental, 2018-12, Vol.238 (C), p.576-585 |
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Main Authors: | , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | [Display omitted]
•Alkaline zirconates work as bifunctional materials: CO2 sorbent and catalytic material in MDR.•Saturated CO2 gas flow only allows obtaining H2 through POM reaction at T > 750 °C.•High H2 production was achieved, using carbonated-ceramics under CO-O2 gas mixture.•High regeneration ability was observed in both ceramics after CO2 capture-MDR cycles.
In this work, H2 production was evaluated using different carbonation conditions and two alkaline zirconates. For this purpose, Li2ZrO3 and Na2ZrO3 were synthesized, characterized and tested on a consecutive process composed of initial CO2 capture, followed by methane dry reforming (MDR). Thermogravimetric results showed that under the four gas mixtures tested (diluted and saturated CO2, CO and CO-O2), both ceramics are able to chemisorb CO2, with Na2ZrO3 having the highest capture with saturated CO2. In catalytic tests, ceramics carbonated with saturated CO2 or CO-O2 gas flows were able to act as sorbents and catalysts, producing H2 at T > 750 °C through the partial oxidation of methane. This reaction was produced because CO2 desorption did not occur, thus avoiding the MDR process. On the other hand, carbonated ceramics under a CO-O2 gas mixture presented an outstanding catalytic performance. Between 450 and 750 °C, H2 was formed through the MDR process promoted by CO2 desorption from both ceramics. This result is in line with CO2 desorption results, where a weaker CO2–solid interaction was observed in comparison with saturated CO2. Afterward, both ceramics presented a similar catalytic behavior, good regeneration and cyclability after the double process proposed (CO2 capture-MDR reaction). Lithium zirconate also presented high thermal stability during cycle tests; meanwhile, sodium zirconate showed an important H2 production increase as a function of cycles. Finally, both materials are feasible options for producing a clean energy source in a moderate temperature range through the catalytic conversion of two greenhouse gases (CO2 and CH4). |
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ISSN: | 0926-3373 1873-3883 |
DOI: | 10.1016/j.apcatb.2018.07.065 |