Correlation between the acid–base properties of the La2O3 catalyst and its methane reactivity

2016 ◽  
Vol 18 (24) ◽  
pp. 16509-16517 ◽  
Author(s):  
Changqing Chu ◽  
Yonghui Zhao ◽  
Shenggang Li ◽  
Yuhan Sun

The linear relationship between CH4 activation energy and CO2 chemisorption energy illuminates the high OCM activity of strongly basic La2O3 catalysts.

Catalysts ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 51
Author(s):  
Pavel Čičmanec ◽  
Jiří Kotera ◽  
Jan Vaculík ◽  
Roman Bulánek

The catalytic activity of zeolites is often related to their acid–base properties. In this work, the relationship between the value of apparent activation energy of ethanol dehydration, measured in a fixed bed reactor and by means of a temperature-programmed surface reaction (TPSR) depending on the amount of ethanol in the zeolite lattice and the value of activation energy of H/D exchange as a measure of acid–base properties of MFI and CHA zeolites, was studied. Tests in a fixed bed reactor were unable to provide reliable reaction kinetics data due to internal diffusion limitations and rapid catalyst deactivation. Only the TPSR method was able to provide activation energy values comparable to the activation energy values obtained from the H/D exchange rate measurements. In addition, for CHA zeolite, it has been shown that the values of ethanol dehydration activation energies depend on the amount of ethanol in the CHA framework, and this effect can be attributed to the substrate clustering effects supporting the deprotonation of zeolite Brønsted centers.


1982 ◽  
Vol 47 (11) ◽  
pp. 2882-2889
Author(s):  
Nadezhda Likhareva ◽  
Ladislav Šůcha ◽  
Miloslav Suchánek

Two new compounds from the formazan series, viz. 1,3-diphenyl-5-(1H-tetrazol-2-yl)formazan and 1,3-diphenyl-5-(2H-1,2,4-triazol-3-yl)formazan, were prepared, and the dissociation constants and molar absorptivities of all of their acid-base species were determined spectrophotometrically employing the SPEKTFOT computer program.


1984 ◽  
Vol 49 (10) ◽  
pp. 2355-2362 ◽  
Author(s):  
Juraj Leško ◽  
Marie Dorušková ◽  
Jan Tržil

Boron oxide in the Na2O.P2O5-x B2O3 system behaves as a Lux base. Its addition to Na2O.P2O5 brings about transformation of a Co(II) indicator from octahedral to tetrahedral configuration, increase in the optical basicity ΛPb(II), increase in the relative basicity of the melt as determined by means of a galvanic cell, and depolymerization reactions releasing PO43- ions. In the Na2O-B2O3 system free of P2O5, boron oxide behaves as a Lux acid. The amphoretic nature of B2O3 is explained in terms of Lux's acid-base theory extended in analogy with the protolysis theory. The theoretical optical basicity values do not indicate the amphoretic behaviour of B2O3 because in this approach boron oxide is a priori regarded as more acidic than Na2O.P2O5.


2016 ◽  
Vol 30 (5) ◽  
pp. e3623 ◽  
Author(s):  
Bagrat A. Shainyan ◽  
Nina N. Chipanina ◽  
Larisa P. Oznobikhina ◽  
Vladimir I. Meshcheryakov

2021 ◽  
pp. 462275
Author(s):  
Paweł Mateusz Nowak ◽  
Mariusz Mitoraj ◽  
Filip Sagan ◽  
Renata Wietecha-Posłuszny

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