Ba-Ce-Ni catalysts for NO direct decomposition

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989100%3A27710%2F22%3A10250673" target="_blank" >RIV/61989100:27710/22:10250673 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Ba-Ce-Ni catalysts for NO direct decomposition

Original language description

This contribution was presented on 15th Pannonian International Symposium on Catalysis. Nitric oxide (NO) harms the human health and environment, causes acid rain, ozone destruction or photochemical smog. Using of direct catalytic decomposition of NO represents suitable way of NO removal without need of reducing agent. Ba-Ce-Ni catalysts were produced by precipitation method from water solution of relevant nitrates and sodium carbonate, dried and calcined at 700 oC for 4 h. One of them was subsequently promoted with potassium by pore filling method. Prepared catalysts were characterized by different types of methods (AAS, N2 physisorption, TPR-H2, TPD-CO2, TPD-NO, XRD, SEM) and tested for NO catalytic decomposition in inert and in the O2 or H2O presence. The presence of NiO, CeO2 and BaCO3 phases was confirmed by XRD. Specific surface area ranged from 1 to 36 m2 g-1 and increased with incorporation of Ce and Ba to NiO, although increasing Ba content caused decrease of specific surface area. Chemical composition strongly influenced achieved NO conversion - catalysts without Ba were not active for NO decomposition, Ba addition to NiO or Ce-Ni oxide caused the increase of catalytic activity. Nevertheless, level of NO conversion was dependent on the Ba content; optimal Ba amount (13 wt. %) ensuring the highest catalytic activity was achieved on the catalyst Ba1.5CeNi9. Surprisingly, incorporation of potassium to Ba-Ce-Ni catalyst had negative effect on NO decomposition. Oxygen (2 mol. %) in the reaction stream caused decrease to almost zero value of NO conversion. Water vapor (2 mol. %) had also negative effect, however, the drop of NO conversion was not so big in the comparison with oxygen inhibition. Catalyst activity inhibition by O2 and H2O was reversible, however the catalysts were not stable in long term tests (60-150 h). The most active catalyst was able to desorb the highest amount of NO as well as O2 (TPD-NO); activity of catalysts increased also with amount desorbed CO2 (TPD-CO2). Ba probably causes weakening of the Ni-O bond, and hence facilitate O2 desorption from the active sites. Due to the synergic effect of Ba and Ce, much more active sites can work on at low temperature.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

20700 - Environmental engineering

Project

<a href="/en/project/EF16_019%2F0000853" target="_blank" >EF16_019/0000853: Institute of Environmental Technology - Excellent Research</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2022

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů