dc.contributor.author | Anastasiadou, T. | en |
dc.contributor.author | Loukatzikou, Loukia A. | en |
dc.contributor.author | Costa, Costas N. | en |
dc.contributor.author | Efstathiou, Angelos M. | en |
dc.creator | Anastasiadou, T. | en |
dc.creator | Loukatzikou, Loukia A. | en |
dc.creator | Costa, Costas N. | en |
dc.creator | Efstathiou, Angelos M. | en |
dc.date.accessioned | 2019-11-21T06:16:20Z | |
dc.date.available | 2019-11-21T06:16:20Z | |
dc.date.issued | 2005 | |
dc.identifier.issn | 1520-6106 | |
dc.identifier.uri | http://gnosis.library.ucy.ac.cy/handle/7/55250 | |
dc.description.abstract | Doping of La2O3 crystallites with Ca2+ ions significantly enhances the intrinsic rate of NO reduction by CH4 in the presence of 5% O2 at 550°C compared to pure La 2O3 and CaO solids, while the opposite is true after doping of CaO with La3+ ions. It was found that the 5 wt % La 2O3-95 wt % CaO system has one of the highest intrinsic site reactivities (TOF = 8.5 × 10-3 s-1) reported at 550°C for the NO/CH4/O2 reaction among metal oxide surfaces. The doping process occurred after first dispersing La 2O3 and CaO crystallites in deionized water heated to 60°C for 90 min, while the dried material was then ground and heated slowly in air to 800°C and kept at this temperature for 5 h. The doping process had the effect of creating surface oxygen vacant sites (F-type defects) in the oxide lattices the concentration of which is a function of the wt % La 2O3 used in the mixed oxide system as revealed by photoluminescence and O2 chemisorption studies. According to DRIFTS 15NO transient isotopic experiments (SSITKA), oxygen vacant sites in Ca2+-doped La2O3 promote the formation of a more active chemisorbed NOx species (NO2 -) that contributes to the enhancement of reaction rate as compared to pure lanthana, calcium oxide, and La3+-doped CaO. These results were supported by the kinetic orders of the reaction with respect to NO and O2 obtained as a function of wt % La2O3 content in the mixed oxide system. Carbon dioxide (a reaction product) competes for the same oxygen vacant sites to form stable adsorbed carbonate-like species, thus lowering the reduction rate of NO. The dependence of the reaction TOF on the wt % La 2O3 loading at 550°C was found to follow the trend of the dependence of photoluminescence intensity on the wt % La2O 3 content in the La2O3-CaO oxide system. © 2005 American Chemical Society. | en |
dc.source | Journal of Physical Chemistry B | en |
dc.source.uri | https://www.scopus.com/inward/record.uri?eid=2-s2.0-23044500945&doi=10.1021%2fjp0515582&partnerID=40&md5=32154751c325493e68e3fe29b5ea6db0 | |
dc.subject | Reaction kinetics | en |
dc.subject | Doping (additives) | en |
dc.subject | Lanthanum compounds | en |
dc.subject | Photoluminescence | en |
dc.subject | Chemisorption | en |
dc.subject | Catalysis | en |
dc.subject | Calcium compounds | en |
dc.subject | Carbonate-like species | en |
dc.subject | Catalytic effect | en |
dc.subject | Cyanides | en |
dc.subject | Mechanistic effect | en |
dc.subject | Process dispersion | en |
dc.title | Understanding the synergistic catalytic effect between la2O 3 and CaO for the CH4 Lean De-NOx reaction: Kinetic and mechanistic studies | en |
dc.type | info:eu-repo/semantics/article | |
dc.identifier.doi | 10.1021/jp0515582 | |
dc.description.volume | 109 | |
dc.description.issue | 28 | |
dc.description.startingpage | 13693 | |
dc.description.endingpage | 13703 | |
dc.author.faculty | 002 Σχολή Θετικών και Εφαρμοσμένων Επιστημών / Faculty of Pure and Applied Sciences | |
dc.author.department | Τμήμα Χημείας / Department of Chemistry | |
dc.type.uhtype | Article | en |
dc.description.notes | <p>Cited By :6</p> | en |
dc.source.abbreviation | J Phys Chem B | en |
dc.contributor.orcid | Efstathiou, Angelos M. [0000-0001-8393-8800] | |
dc.contributor.orcid | Costa, Costas N. [0000-0002-8459-0356] | |
dc.gnosis.orcid | 0000-0001-8393-8800 | |
dc.gnosis.orcid | 0000-0002-8459-0356 | |