Co-Mn-Al Mixed Oxides Promoted by K for Direct NO Decomposition: Effect of Preparation Parameters.

0511878 - ÚCHP 2020 RIV CH eng J - Journal Article
Pacultová, K. - Bílková, T. - Klegová, A. - Karásková, K. - Fridrichová, D. - Jirátová, Květa - Kiška, T. - Balabánová, Jana - Koštejn, Martin - Kotarba, A. - Kaspera, W. - Stelmachowski, P. - Słowik, G. - Obalová, L.
Co-Mn-Al Mixed Oxides Promoted by K for Direct NO Decomposition: Effect of Preparation Parameters.
Catalysts. Roč. 9, č. 7 (2019), č. článku 593. E-ISSN 2073-4344
R&D Projects: GA ČR(CZ) GA18-19519S
Institutional support: RVO:67985858
Keywords : nitric oxide * catalytic decomposition * potassium promoter
OECD category: Chemical process engineering
Impact factor: 3.520, year: 2019
Method of publishing: Open access
https://www.mdpi.com/2073-4344/9/7/593

Fundamental research on direct NO decomposition is still needed for the design of a suffciently active, stable and selective catalyst. Co-based mixed oxides promoted by alkali metals
are promising catalysts for direct NO decomposition, but which parameters play the key role in NO decomposition over mixed oxide catalysts? How do applied preparation conditions a ect
the obtained catalyst’s properties? Co4MnAlOx mixed oxides promoted by potassium calcined at various conditions were tested for direct NO decomposition with the aim to determine their
activity, stability and selectivity. The catalysts were prepared by co-precipitation of the corresponding nitrates and subsequently promoted by KNO3. The catalysts were characterized by atomic absorption spectrometry (AAS)/inductive coupled plasma (ICP), X-ray photoelectron spectrometry (XPS), XRD, N2 physisorption, temperature programmed desorption ofCO2 (TPD-CO2), temperature programmed reduction by hydrogen (TPR-H2), species-resolved thermal alkali desorption (SR-TAD), work function measurement and STEM. The preparation procedure affects physico-chemical properties of the catalysts, especially those that are associated with the potassium promoter presence. The addition of K is essential for catalytic activity, as it substantially ffects the catalyst reducibility and basicity—key properties of a deNO catalyst. However, SR-TAD revealed that potassium migration, redistribution and volatilization are strongly dependent on the catalyst calcination temperature—higher calcination temperature leads to potassium stabilization. It also caused the formation of new phases and thus affected the main properties—SBET, crystallinity and residual potassium amount.
Permanent Link: http://hdl.handle.net/11104/0302122