Zeolite ZSM-5 Containing Copper Ions: The Effect of the Copper Salt Anion and NH4OH/Cu2+ Ratio on the State of the Copper Ions and on the Reactivity of the Zeolite in DeNOx Full article
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Kinetics and Catalysis
ISSN: 0023-1584 , E-ISSN: 1608-3210 |
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| Output data | Year: 2016, Volume: 57, Number: 6, Pages: 776-796 Pages count : 21 DOI: 10.1134/S0023158416060161 | ||||
| Tags | Cu-ZSM-5, DeNOx, ion exchange, IR spectroscopy, SCR of NO with propane, sorption isotherm, UV-Vis diffuse reflectance spectroscopy | ||||
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Funding (1)
| 1 | Federal Agency for Scientific Organizations | V.46.5.6. |
Abstract:
Isotherms of copper cation sorption by H-ZSM-5 zeolite from aqueous and aqueous ammonia solutions of copper acetate, chloride, nitrate, and sulfate are considered in terms of Langmuir’s monomolecular adsorption model. Using UV-Vis diffuse reflectance spectroscopy, IR spectroscopy, and temperatureprogrammed reduction with hydrogen and carbon monoxide, it has been demonstrated that the electronic state of the copper ions is determined by the ion exchange and heat treatment conditions. The state of the copper ions has an effect on the redox properties and reactivity of the Cu-ZSM-5 catalysts in the selective catalytic reduction (SCR) of NO with propane and in N2O decomposition. The amount of Cu2+ that is sorbed by zeolite H-ZSM-5 from aqueous solution and is stabilized as isolated Cu2+ cations in cationexchange sites of the zeolite depends largely on the copper salt anion. The quantity of Cu(II) cations sorbed from aqueous solutions of copper salts of strong acids is smaller than the quantity of the same cations sorbed from the copper acetate solution. When copper chloride or sulfate is used, the zeolite is modified by the chloride or sulfate anion. Because of the presence of these anions, the redox properties and nitrogen oxides removal (DeNOx) efficiency of the Cu-ZSM-5 catalysts prepared using the copper salts of strong acids are worse than the same characteristics of the sample prepared using the copper acetate solution. The addition of ammonia to the aqueous solutions of copper salts diminishes the copper salt anion effect on the amount of Cu(II) sorbed from these solutions and hampers the nonspecific sorption of anions on the zeolite surface. As a consequence, the redox and DeNOx properties of Cu-ZSM-5 depend considerably on the NH4OH/Cu2+ ratio in the solution used in ion exchange. The aqueous ammonia solutions of the copper salts with NH4OH/Cu2+ = 6–10 stabilize, in the Cu-ZSM-5 structure, Cu2+ ions bonded with extraframework oxygen, which are more active in DeNOx than isolated Cu2+ ions (which form at NH4OH/Cu2+ = 30) or nanosized CuO particles (which form at NH4OH/Cu2+ = 3).
Cite:
Yashnik S.A.
, Ismagilov Z.R.
Zeolite ZSM-5 Containing Copper Ions: The Effect of the Copper Salt Anion and NH4OH/Cu2+ Ratio on the State of the Copper Ions and on the Reactivity of the Zeolite in DeNOx
Kinetics and Catalysis. 2016. V.57. N6. P.776-796. DOI: 10.1134/S0023158416060161 WOS Scopus РИНЦ AN OpenAlex
Zeolite ZSM-5 Containing Copper Ions: The Effect of the Copper Salt Anion and NH4OH/Cu2+ Ratio on the State of the Copper Ions and on the Reactivity of the Zeolite in DeNOx
Kinetics and Catalysis. 2016. V.57. N6. P.776-796. DOI: 10.1134/S0023158416060161 WOS Scopus РИНЦ AN OpenAlex
Original:
Яшник С.А.
, Исмагилов З.Р.
Цеолиты ZSM-5, содержащие ионы меди: влияние аниона соли меди и NH4OH/Cu2+ на состояние ионов меди и реакционную способность в DeNOX
Кинетика и катализ. 2016. Т.57. №6. С.777-799. DOI: 10.7868/S0453881116060174 РИНЦ OpenAlex
Цеолиты ZSM-5, содержащие ионы меди: влияние аниона соли меди и NH4OH/Cu2+ на состояние ионов меди и реакционную способность в DeNOX
Кинетика и катализ. 2016. Т.57. №6. С.777-799. DOI: 10.7868/S0453881116060174 РИНЦ OpenAlex
Dates:
| Submitted: | Jul 21, 2015 |
| Published print: | Nov 1, 2016 |
| Published online: | Dec 2, 2016 |
Identifiers:
| Web of science: | WOS:000389905600008 |
| Scopus: | 2-s2.0-84999853141 |
| Elibrary: | 27591313 |
| Chemical Abstracts: | 2016:1986097 |
| OpenAlex: | W2559128071 |