Balancing surface acidity, oxygen vacancies and Cu+ of CuOx/CeO2 catalysts by Nb doping for enhancing CO oxidation and moisture resistance and lowering byproducts in plasma catalysis

2021 ◽  
pp. 128564
Author(s):  
Jian Zhang ◽  
Lisha Wang ◽  
Xueyu Hu ◽  
Qi Shao ◽  
Xiaoming Xu ◽  
...  
Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 946
Author(s):  
Grêce Abdallah ◽  
Jean-Marc Giraudon ◽  
Rim Bitar ◽  
Nathalie De Geyter ◽  
Rino Morent ◽  
...  

Trichloroethylene (TCE) removal was investigated in a post-plasma catalysis (PPC) configuration in nearly dry air (RH = 0.7%) and moist air (RH = 15%), using, for non-thermal plasma (NTP), a 10-pin-to-plate negative DC corona discharge and, for PPC, Ce0.01Mn as a catalyst, calcined at 400 °C (Ce0.01Mn-400) or treated with nitric acid (Ce0.01Mn-AT). One of the key points was to take advantage of the ozone emitted from NTP as a potential source of active oxygen species for further oxidation, at a very low temperature (100 °C), of untreated TCE and of potential gaseous hazardous by-products from the NTP. The plasma-assisted Ce0.01Mn-AT catalyst presented the best CO2 yield in dry air, with minimization of the formation of gaseous chlorinated by-products. This result was attributed to the high level of oxygen vacancies with a higher amount of Mn3+, improved specific surface area and strong surface acidity. These features also allow the promotion of ozone decomposition efficiency. Both catalysts exhibited good stability towards chlorine. Ce0.01Mn-AT tested in moist air (RH = 15%) showed good stability as a function of time, indicating good water tolerance also.


Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 312 ◽  
Author(s):  
Antonella Glisenti ◽  
Andrea Vittadini

The effects of modifying the composition of LaCoO3 on the catalytic activity are predicted by density functional calculations. Partially replacing La by Sr ions has benefical effects, causing a lowering of the formation energy of O vacancies. In contrast to that, doping at the Co site is less effective, as only 3d impurities heavier than Co are able to stabilize vacancies at high concentrations. The comparison of the energy profiles for CO oxidation of undoped and of Ni-, Cu-m and Zn-doped (La,Sr)CoO3(100) surface shows that Cu is most effective. However, the effects are less spectacular than in the SrTiO3 case, due to the different energetics for the formation of oxygen vacancies in the two hosts.


2020 ◽  
Vol 20 (5) ◽  
pp. 2791-2802
Author(s):  
Duangamol Ongmali ◽  
Sakollapath Pithakratanayothin ◽  
Sureerat Jampa ◽  
Apanee Luengnaruemitrchai ◽  
Thanyalak Chaisuwan ◽  
...  

In this work, a ceria (CeO2) support was modified with titania (TiO2) by nanocasting using MCM-48 as a hard template and then loading Cu (as the nitrate salt) at different levels (3–9% by weight) by deposition-precipitation followed by calcination. The addition of TiO2 in MSP CeO2 revealed that the MSP CeO2 was significantly improved the oxygen vacancies of the catalyst by increasing the Ce3+ content from 38 to 75% and stabilizing the Ce3+ species by bonding with the oxygen as Ce(4f)-O(2p)-Ti(3d). Moreover, the bonding of MSP CeO2 with TiO2 generated the oxygen defect vacancies (s–Ti3+), allowing Cu2+ to occupy and be reduced to Cu+ during calcination. The smaller CeO2 crystallite size (2.7 nm) of 9Cu/CeO2–TiO2 increased the mass-specific CO-Oxidation, showing the best catalytic activity due to its highest redox properties, as determined by H2-TPR and also showing resistant property to water and carbon dioxide. Indeed, water was adsorbed on the Ce3+ sites, generating OHads which reacted with CO to form –COOH, resulting in CO2.


RSC Advances ◽  
2014 ◽  
Vol 4 (22) ◽  
pp. 11322-11330 ◽  
Author(s):  
Putla Sudarsanam ◽  
Baithy Mallesham ◽  
D. Naga Durgasri ◽  
Benjaram M. Reddy

Fe-doped CeO2 nano-oxide exhibited superior CO oxidation activity compared to pristine CeO2 due to its facile reducible nature, enhanced lattice strain, and ample oxygen vacancies.


Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1223
Author(s):  
James K. Aldridge ◽  
Louise R. Smith ◽  
David J. Morgan ◽  
Albert F. Carley ◽  
Mandy Humphreys ◽  
...  

A series of Pt-based catalysts were synthesised and investigated for ambient temperature CO oxidation with the aim to increase catalytic activity and improve moisture resistance through support modification. Initially, bimetallic PtPd catalysts supported on alumina were found to exhibit superior catalytic activity compared with their monometallic counterparts for the reaction. Following an investigation into the effect of Pt/Pd ratio, a composition of 0.1% Pt/0.4% Pd was selected for further studies. Following this, SnO2/Al2O3 supports were synthesised from a variety of tin oxide sources. Catalytic activity was improved using sodium stannate and tin oxalate precursors compared with a traditional tin oxide slurry. Catalytic activity versus tin concentration was found to vary significantly across the three precursors, which was subsequently investigated by X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDX).


RSC Advances ◽  
2016 ◽  
Vol 6 (74) ◽  
pp. 70653-70659 ◽  
Author(s):  
Yanjie Zhang ◽  
Yanyan Zhao ◽  
Han Zhang ◽  
Liyuan Zhang ◽  
Huipeng Ma ◽  
...  

Metal (Au or Pt)-modified CeO2 materials with excellent redox ability for the oxidation of CO to CO2 were prepared by a redox precipitation method and a certain amount (4.2%) of oxygen vacancies was necessary to improve the CO oxidation on Pt-CeO2.


2002 ◽  
Vol 36 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Jiunn-Nan Lin ◽  
Jen-Ho Chen ◽  
Chih-Yang Hsiao ◽  
Yih-Ming Kang ◽  
Ben-Zu Wan

RSC Advances ◽  
2014 ◽  
Vol 4 (25) ◽  
pp. 13145-13152 ◽  
Author(s):  
F. Romero-Sarria ◽  
J. J. Plata ◽  
O. H. Laguna ◽  
A. M. Márquez ◽  
M. A. Centeno ◽  
...  

2014 ◽  
Vol 4 (11) ◽  
pp. 3826-3834 ◽  
Author(s):  
Feng Zhang ◽  
Tao Li ◽  
Li Pan ◽  
Aravind Asthagiri ◽  
Jason F. Weaver

Strong binding on oxygen vacancies and metallic domains promotes CO oxidation on partially-reduced PdO(101), while adsorption only on metallic sites promotes CO oxidation when 2D oxide coexists with Pd(111).


2019 ◽  
Vol 2019 (13) ◽  
pp. 1714-1723 ◽  
Author(s):  
Baolin Liu ◽  
Yizhao Li ◽  
Yali Cao ◽  
Lei Wang ◽  
Shaojun Qing ◽  
...  

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