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

ChemInform ◽  
2010 ◽  
Vol 31 (31) ◽  
pp. no-no
Author(s):  
Jiri Dedecek ◽  
Alena Vondrova ◽  
Jiri Cejka
Keyword(s):  
Catalytic Activity ◽  
Charge Density ◽  
Molecular Sieves ◽  
Oxide Decomposition

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.

Combined Alkali‐Organoammonium Structure Direction of High‐Charge‐Density Heteroatom‐Containing Aluminophosphate Molecular Sieves

2019 ◽  
Vol 58 (27) ◽  
pp. 9032-9037 ◽  
Author(s):  
Seungwan Seo ◽  
Nak Ho Ahn ◽  
Jeong Hwan Lee ◽  
Lisa M. Knight ◽  
Jaime G. Moscoso ◽  
...  
Keyword(s):  
Charge Density ◽  
Molecular Sieves ◽  
High Charge ◽  
Aluminophosphate Molecular Sieves ◽  
High Charge Density

Synthesis, characterization and catalytic activity of actinide Th-MCM-41 and U-MCM-41 hexagonal packed mesoporous molecular sieves

2001 ◽  
Vol 171 (1-2) ◽  
pp. 229-241 ◽  
Author(s):  
Rodica Tismaneanu ◽  
Biswajit Ray ◽  
Rafael Khalfin ◽  
Rafi Semiat ◽  
Moris S. Eisen
Keyword(s):  
Catalytic Activity ◽  
Molecular Sieves ◽  
Mesoporous Molecular Sieves ◽  
Mcm 41

Combined Alkali‐Organoammonium Structure Direction of High‐Charge‐Density Heteroatom‐Containing Aluminophosphate Molecular Sieves

2019 ◽  
Vol 131 (27) ◽  
pp. 9130-9135 ◽  
Author(s):  
Seungwan Seo ◽  
Nak Ho Ahn ◽  
Jeong Hwan Lee ◽  
Lisa M. Knight ◽  
Jaime G. Moscoso ◽  
...  
Keyword(s):  
Charge Density ◽  
Molecular Sieves ◽  
High Charge ◽  
Aluminophosphate Molecular Sieves ◽  
High Charge Density

Immobilization of metalloporphyrin complexes in molecular sieves and their catalytic activity

2005 ◽  
Vol 6 (8) ◽  
pp. 531-538 ◽  
Author(s):  
V. Radha Rani ◽  
M. Radha Kishan ◽  
S.J. Kulkarni ◽  
K.V. Raghavan
Keyword(s):  
Catalytic Activity ◽  
Molecular Sieves

Catalytic activity of nitrogen-containing molecular sieves and nitrogen-containing carbon for α,β-unsaturated esters production

2011 ◽  
Vol 172 (2-3) ◽  
pp. 1054-1065 ◽  
Author(s):  
Izabel M. Nogueira ◽  
Josue M. Filho ◽  
Pedro Hermano M. de Vasconcelos ◽  
Gilberto D. Saraiva ◽  
Alcineia C. Oliveira
Keyword(s):  
Catalytic Activity ◽  
Molecular Sieves ◽  
Unsaturated Esters

Catalytic Activity of Dehydrogenation of Methanol to MF over Cu/MCM-41 and Cu-ZnO/MCM-41 Prepared by Impregnation and Grinding

2011 ◽  
Vol 396-398 ◽  
pp. 730-733
Author(s):  
Guo Ru Li ◽  
Gong Li ◽  
Shu Xi Zhou ◽  
Hui Juan Tong
Keyword(s):  
Catalytic Activity ◽  
Atmospheric Pressure ◽  
Molecular Sieves ◽  
Conversion Rate ◽  
Methyl Formate ◽  
Methanol Conversion ◽  
N2 Adsorption ◽  
Flow Microreactor ◽  
Adsorption Desorption ◽  
Mcm 41

Abstract. Using MCM-41 molecular sieves as the support, Cu-ZnO/MCM-41 and Cu/MCM-41 catalysts were prepared by impregnation and grinding. The catalysts were characterized by XRD, N2 adsorption-desorption and TPR methods. The catalytic activity of the dehydrogenation of methanol to methyl formate (MF) was evaluated using the flow microreactor under atmospheric pressure. According to the results, the catalyst prepared by impregnation had a better selectivity for the MF, but a lower methanol conversion rate. However, the product's selectivity could be improved by adding ZnO additive while the methanol conversion rate was reduced. For Cu/MCM-41 prepared by impregnation and grinding, the methanol conversion rate was 20.18% and 24.13% respectively at 250°C and the MF selectivity was 73.75% and 67.35% respectively. Likewise for Cu-ZnO/MCM-41 prepared by impregnation and grinding, the methanol conversion rate was 15.28% and 18.83% respectively at 250°C and the MF selectivity was 81.31% and 75.32% respectively.

Catalytic Activity of Heteropolytungstic Acid Encapsulated into Mesoporous Material Structure

2007 ◽  
Vol 5 (1) ◽  
Author(s):  
Gonul Gunduz ◽  
Rayna P. Dimitrova ◽  
Selahattin Yilmaz
Keyword(s):  
Catalytic Activity ◽  
Molecular Sieves ◽  
Mesoporous Material ◽  
Heteropoly Acid ◽  
Methanol Conversion ◽  
Tungstophosphoric Acid ◽  
Material Structure ◽  
Acetate Oxidation ◽  
Mcm 41 ◽  
Model Reactions

The paper presents a spectroscopic and catalytic study of encapsulated Keggin type heteropoly acid (12-tungstophosphoric acid, HPW) in the mesopores of MCM-41 molecular sieves. Nitrogen physisorption, FTIR, SEM, XRD and catalytic methods have been used to characterize and compare the properties of the samples. Methanol conversion, ?-pinene isomerization and ethyl acetate oxidation have been applied as model reactions for the evaluation of acid site activity. The combined physicochemical and catalytic investigations clearly show that the introduction of 12-tungstophosphoric acid into MCM-41 causes significant changes in the properties of the sample.

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