scholarly journals Mesoporous MnOx–CeO2 composites for NH3-SCR: the effect of preparation methods and a third dopant

RSC Advances ◽  
2019 ◽  
Vol 9 (21) ◽  
pp. 11912-11921 ◽  
Author(s):  
Li Weiman ◽  
Liu Haidi ◽  
Chen Yunfa

In this study, an optimal oxalate route was used to obtain nickel/cobalt doped MnOx–CeO2 mixed oxides. Nickel doped MnOx–CeO2 showed excellent NH3-SCR activity and H2O + SO2 resistance.

2014 ◽  
Vol 917 ◽  
pp. 360-364 ◽  
Author(s):  
M. Abdus Salam ◽  
Suriati Sufian

Micro-mesoporous mixed oxides containing nickel, cobalt and aluminum have been synthesized using conventional coprecipitation method. FESEM and HRTEM analyses demonstrated the flower and hexagonal plate-like nanostructured of mixed oxides. Different mixed oxide formation, homogenous metal dispersion, textural properties were investigated using XRD, ICP-MS and BET (N2 adsorption-desorption) techniques. nanostructured mixed oxides exhibited 2.6 wt% hydrogen adsorption that were studied using temperature programmed reduction-adsorption-desorption (H2-TPR/TPD) and thermogravimetric and differential thermal analysis (TGA-DTA) techniques. Investigation corresponds that morphologies, textural properties and surface energy of mixed oxides are important in hydrogen adsorption.


2020 ◽  
Vol 15 (2) ◽  
pp. 490-500
Author(s):  
Neha Neha ◽  
Ram Prasad ◽  
Satya Vir Singh

A series of nickel-cobalt bimetal oxides in varying molar ratios and its single metal oxides were synthesized by reactive calcination of coprecipitated basic-carbonates. Several characterization techniques, such as: Bruneuer Emmett Teller (BET), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infra Red (FTIR), and Hydrogen Temperature Programmed Reduction (H2-TPR), were performed over the oxides. Activities of oxides were evaluated in methane total oxidation in the presence or the absence of CO. The best catalytic performance was observed over NiCo catalyst with a Ni/Co molar ratio of 1:1, and the complete conversion of CO-CH4 mixture was achieved at 390 °C. Moreover, the presence of carbon monoxide improves CH4 total oxidation over nickel-cobalt mixed oxides. Structural analysis reveals that the insertion of nickel into the spinel lattice of cobalt oxide causes the structural disorder, which probably caused the increase of the amount of octahedrally coordinated divalent nickel cations that are responsible for catalytic activity. Stability of the best-performed catalyst has been tested in the two conditions, showing remarkable long-term stability and thermal stability, however, showed deactivation after thermally ageing at 700 °C. Copyright © 2020 BCREC Group. All rights reserved 


2020 ◽  
Vol 503 ◽  
pp. 144190 ◽  
Author(s):  
Qiulin Zhang ◽  
Yaqing Zhang ◽  
Tengxiang Zhang ◽  
Huimin Wang ◽  
YanPing Ma ◽  
...  

2013 ◽  
Vol 262 ◽  
pp. 782-788 ◽  
Author(s):  
Huazhen Chang ◽  
Lei Ma ◽  
Shijian Yang ◽  
Junhua Li ◽  
Liang Chen ◽  
...  

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 361
Author(s):  
Ming Cai ◽  
Xue Bian ◽  
Feng Xie ◽  
Wenyuan Wu ◽  
Peng Cen

Selective catalytic reduction of nitrogen oxides with NH3 (NH3-SCR) is still the most commonly used control technology for nitrogen oxides emission. Specifically, the application of rare earth materials has become more and more extensive. CeO2 was widely developed in NH3-SCR reaction due to its good redox performance, proper surface acidity and abundant resource reserves. Therefore, a large number of papers in the literature have described the research of cerium-based catalysts. This review critically summarized the development of the different components of cerium-based catalysts, and characterized the preparation methods, the catalytic performance and reaction mechanisms of the cerium-based catalysts for NH3-SCR. The purpose of this review is to highlight: (1) the modification effect of the various metal elements for cerium-based catalysts; (2) various synthesis methods of the cerium-based catalysts; and (3) the physicochemical properties of the various catalysts and clarify their relations to catalytic performances, particularly in the presence of SO2 and H2O. Finally, we hope that this work can give timely technical guidance and valuable insights for the applications of NH3-SCR in the field of NOx control.


Ionics ◽  
2002 ◽  
Vol 8 (1-2) ◽  
pp. 92-99 ◽  
Author(s):  
C. Vogler ◽  
B. Löffler ◽  
W. Weirather ◽  
M. Wohlfahrt-Mehrens ◽  
J. Garche

Sign in / Sign up

Export Citation Format

Share Document