Low-temperature CO oxidation on Ag/ZSM-5 catalysts: Influence of Si/Al ratio and redox pretreatments on formation of silver active sites; Fuel; Vol. 188

Low-temperature CO oxidation on Ag/ZSM-5 catalysts: Influence of Si/Al ratio and redox pretreatments on formation of silver active sites; Fuel; Vol. 188

Bibliografiske detaljer
Parent link:Fuel
Vol. 188.— 2016.— [P. 121-131]
Institution som forfatter: Национальный исследовательский Томский политехнический университет Энергетический институт Кафедра автоматизации теплоэнергетических процессов
Andre forfattere: Kolobova E. N. Ekaterina Nikolaevna, Pestryakov A. N. Aleksey Nikolaevich, Mamontov G. V. Grigory Vladimirovich, Kotolevich Yu. I. Yuliya I., Bogdanchikova N. E. Nina Evgenjevna, Farias M. H., Vosmerikov A. V., Vosmerikova L. V., Cortes C. V.
Summary:Title screen
Silver catalysts supported on ZSM-5 (Si/Al = 30, 50 and 80) were investigated for low-temperature CO oxidation to study the nature of the silver active sites and their formation under the influence of the support chemical composition and redox pretreatments. The catalysts were characterized by HRTEM, FTIR, XPS, diffuse reflectance UV–Vis spectroscopy, NH3 thermodesorption (NH3 TPD) and temperature-programmed reduction (H2 TPR). The chemical composition (Si/Al ratio) of the ZSM-5 zeolite support significantly affects catalytic properties of Ag/ZSM-5 samples: the lower the Broensted acidity of the zeolite support, the higher the activity of the catalysts. Interestingly, while oxidizing pretreatment of catalysts led to a significantly better performance than reducing pretreatments, the consecutive reducing treatment of the preoxidized samples significantly promoted the catalytic activity for low-temperature CO oxidation. Thus, Ag/ZMS-5 catalyst with Si/Al = 80, pretreated consecutively in oxidizing and reducing conditions, showed the highest activity, reaching 90% CO conversion at just 40 °C. Comparison of activity and characterization results showed that silver particles with size below 2 nm are the most active; larger particles are just “spectators”. The most probable silver active centers in the low-temperature CO oxidation are ionic species, mostly charged clusters Agn?+, strongly interacting with the support. The obtained results in low-temperature CO oxidation might be of particular interest for neutralization of exhaust gases of car engines during “cold start”.
Режим доступа: по договору с организацией-держателем ресурса
Sprog:engelsk
Udgivet: 2016
Fag:
труды учёных ТПУ
электронный ресурс
низкие температуры
окисление
серебряные катализаторы
Online adgang:http://dx.doi.org/10.1016/j.fuel.2016.10.037
Format: Electronisk Book Chapter
KOHA link:https://koha.lib.tpu.ru/cgi-bin/koha/opac-detail.pl?biblionumber=651605

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