Catalytic Activity of Cu Ion-Exchanged Metalloaluminophosphates in NO Decomposition

1998 ◽  
Vol 63 (11) ◽  
pp. 1755-1768 ◽  
Author(s):  
Jiří Dědeček ◽  
Alena Vondrová ◽  
Jiří Čejka
Keyword(s):  
Catalytic Activity ◽  
Metal Ions ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Negative Charge ◽  
Divalent Metal ◽  
No Decomposition ◽  
Divalent Metal Ions ◽  
Cu Ions

NO decomposition was investigated over Cu ion-exchanged aluminophosphate molecular sieve catalysts. Cu ions in cationic positions balanced by one framework negative charge in the metalloaluminophosphates of AlPO-5 and AlPO-11 structures exhibited catalytic activity in NO decomposition comparable with that of Cu-ZSM-5. No catalytic activity of the Cu ions incorporated during synthesis of molecular sieves into the framework in tetrahedral positions (CuAlPO-11) was observed. The catalytic activity of Cu-MeAlPO-5 and Cu-MeAlPO-11 was observed with various divalent metal ions of the MeAlPO-5 and MeAlPO-11 frameworks (Me = Zn, Mg, Fe, Co) and also with Cu exchanged SAPO-5 molecular sieves. The Cu-MeAlPO-5 and Cu-MeAlPO-11 catalysts differed only in the temperature of the maximum observed catalytic activity.

Effect of Framework Charge Density on Catalytic Activity of Copper Loaded Molecular Sieves of Chabazite Structure in Nitrogen(II) Oxide Decomposition

2000 ◽  
Vol 65 (3) ◽  
pp. 343-351 ◽  
Author(s):  
Jiří Dědeček ◽  
Alena Vondrová ◽  
Jiří Čejka
Keyword(s):  
Catalytic Activity ◽  
Charge Density ◽  
High Activity ◽  
Molecular Sieves ◽  
Negative Charge ◽  
No Decomposition ◽  
Negative Charge Density ◽  
Oxide Decomposition ◽  
Cu Ions

NO decomposition over Cu-loaded molecular sieves of chabazite structure with different framework negative charge density was investigated. Cu-ZnAlPO-34 with framework charge density (Al + P)/Zn = 15 exhibited high and stable catalytic activity in NO decomposition while Cu-chabazite with Si/Al = 2.7 was inactive. This evidences that the number of aluminum atoms balancing Cu ions in cationic sites controls the catalytic activity of Cu ion. Ions balanced by single framework aluminum atoms exhibit high activity in NO decomposition while ions balanced by two framework aluminum atoms are inactive. Topology of cationic sites is not the limiting parameter for NO decomposition over Cu ions located in molecular sieves.

Interaction of divalent metal ions with the NADP+-malic enzyme from maize leaves

1991 ◽  
Vol 81 (4) ◽  
pp. 462-466 ◽  
Author(s):  
Maria Fabiana Drincovich ◽  
Alberto A. Iglesias ◽  
Carlos S. Andreo
Keyword(s):  
Metal Ions ◽  
Malic Enzyme ◽  
Divalent Metal ◽  
Divalent Metal Ions ◽  
Maize Leaves

scholarly journals Regulation of divalent metal ions to the aggregation and membrane damage of human islet amyloid polypeptide oligomers

RSC Advances ◽  
2021 ◽  
Vol 11 (21) ◽  
pp. 12815-12825
Author(s):  
Yajie Wang ◽  
Feihong Meng ◽  
Tong Lu ◽  
Chunyun Wang ◽  
Fei Li
Keyword(s):  
Metal Ions ◽  
Metal Binding ◽  
Membrane Damage ◽  
Islet Amyloid Polypeptide ◽  
Divalent Metal ◽  
Human Islet ◽  
Divalent Metal Ions ◽  
Islet Amyloid ◽  
Induced Membrane ◽  
Human Islet Amyloid Polypeptide

Their is a counteraction between a decrease in the disruptive ability of metal-associated oligomer species and an increase in the quantity of oligomers promoted by the metal binding in the activity of hIAPP induced membrane damage.

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