scholarly journals Selectivity in heterovalent anion exchange. Ion pairing vs. ion hydration

1972 ◽  
Vol 76 (17) ◽  
pp. 2459-2462 ◽  
Author(s):  
J. Bucher ◽  
R. M. Diamond ◽  
B. Chu
Keyword(s):  
Anion Exchange ◽  
Ion Pairing ◽  
Ion Hydration

Ion Hydration and Ion Pairing as Probed by THz Spectroscopy

2019 ◽  
Vol 58 (10) ◽  
pp. 3000-3013 ◽  
Author(s):  
Gerhard Schwaab ◽  
Federico Sebastiani ◽  
Martina Havenith
Keyword(s):  
Ion Pairing ◽  
Thz Spectroscopy ◽  
Ion Hydration

Anion-Exchange-Triggered 1,3-Shift of an NH Proton to Iridium in Protic N-Heterocyclic Carbenes: Hydrogen-Bonding and Ion-Pairing Effects

2009 ◽  
Vol 49 (5) ◽  
pp. 912-917 ◽  
Author(s):  
Guoyong Song ◽  
Yan Su ◽  
Roy A. Periana ◽  
Robert H. Crabtree ◽  
Keli Han ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Anion Exchange ◽  
Ion Pairing ◽  
Heterocyclic Carbenes

Anion-Exchange-Triggered 1,3-Shift of an NH Proton to Iridium in Protic N-Heterocyclic Carbenes: Hydrogen-Bonding and Ion-Pairing Effects

2010 ◽  
Vol 122 (5) ◽  
pp. 924-929 ◽  
Author(s):  
Guoyong Song ◽  
Yan Su ◽  
Roy A. Periana ◽  
Robert H. Crabtree ◽  
Keli Han ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Anion Exchange ◽  
Ion Pairing ◽  
Heterocyclic Carbenes

A Study of the Use of Solubility Isotherms to Obtain Information about Ion Hydration and Ion Pairing in Concentrated Solutions of Electrolytes

1994 ◽  
Vol 59 (1) ◽  
pp. 126-137 ◽  
Author(s):  
Jitka Eysseltová
Keyword(s):  
Computational Analysis ◽  
Ternary Systems ◽  
Ion Pairing ◽  
Electrolyte Solutions ◽  
Model Systems ◽  
Concentrated Solutions ◽  
Ion Hydration ◽  
Solutions Of Electrolytes ◽  
Common Ion ◽  
Solubility Isotherms

Computational analysis of solubility isotherms in ternary systems consisting of water and two solutes having a common ion was suggested and the respective software was developed. This hydration analysis was applied to model systems NH4CNS - NaCNS - H2O at 5, 25 and 50 °C and NaX - KX - H2O (X = Cl, Br, I) at 25 °C. The results obtained are discussed and the way in which the hydration analysis gives information on ionic processes in saturated electrolyte solutions is demonstrated.

Hydration of ferric chloride and nitrate in aqueous solutions: water-mediated ion pairing revealed by Raman spectroscopy

2019 ◽  
Vol 21 (35) ◽  
pp. 19172-19180
Author(s):  
Stephen M. Baumler ◽  
William H. Hartt V. ◽  
Heather C. Allen
Keyword(s):  
Raman Spectroscopy ◽  
Aqueous Solutions ◽  
Ferric Chloride ◽  
Ion Pairing ◽  
Ion Pair ◽  
Pair Formation ◽  
Ferric Ion ◽  
Ion Hydration ◽  
Ion Pair Formation

Ferric ion hydration differences are governed by ion pair formation uniquely affected by anion identity.

Bovine Factors X1And X2: Activation Peptide Based Chromatographic Differences

1979 ◽  
Author(s):  
Takashi Morita ◽  
Craig Jackson
Keyword(s):  
Amino Acid ◽  
Anion Exchange ◽  
Gel Filtration ◽  
Heart Association ◽  
Personal Communication ◽  
Exchange Chromatography ◽  
Amino Acid Sequences ◽  
Factor X ◽  
Activation Peptide ◽  
Activation Peptides

Bovine Factor X is eluted in two forms (X1and X2) from anion exchange chromatographic columns. These two forms have indistinguishable amino acid compositions, molecular weights and specific activities. The amino acid sequences containing the γ-carboxyglutamic acid residues have been shown to be identical in X1 and X2(H. Morris, personal communication). An activation peptide is released from the N-terminal region of the heavy chain of Factor X by an activator from Russell’s viper venom. This peptide can be isolated after activation by gel filtration on Sephadex G-100 under nondenaturing conditions. The activation peptides from a mixture of Factors X1 and X2 were separated into two forms by anion-exchange chromatography. The activation peptide (AP1) which eluted first was shown to be derived from Factor X1. while the activation peptiae (AP2) which eluted second was shown to be derived from X2 on the basis of chromatographic separations carried out on Factors X1 and X2 separately. Factor Xa was eluted as a symmetrical single peak. On the basis of these and other data characterizing these products, we conclude that the difference between X1 and X2 are properties of the structures of the activation peptides. (Supported by a grant HL 12820 from the National Heart, Lung and Blood Institute. C.M.J. is an Established Investigator of the American Heart Association).

Enhanced catalytic activity of low-Pt content nanocatalysts supported on hollow carbon spheres for the ORR in alkaline media

MRS Advances ◽  
2020 ◽  
Vol 5 (57-58) ◽  
pp. 2961-2972
Author(s):  
P.C. Meléndez-González ◽  
E. Garza-Duran ◽  
J.C. Martínez-Loyola ◽  
P. Quintana-Owen ◽  
I.L. Alonso-Lemus ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Anion Exchange ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Alkaline Media ◽  
High Catalytic Activity ◽  
Average Particle ◽  
Carbon Spheres ◽  
Hollow Carbon ◽  
Hollow Carbon Spheres

In this work, low-Pt content nanocatalysts (≈ 5 wt. %) supported on Hollow Carbon Spheres (HCS) were synthesized by two routes: i) colloidal conventional polyol, and ii) surfactant-free Bromide Anion Exchange (BAE). The nanocatalysts were labelled as Pt/HCS-P and Pt/HCS-B for polyol and BAE, respectively. The physicochemical characterization of the nanocatalysts showed that by following both methods, a good control of chemical composition was achieved, obtaining in addition well dispersed nanoparticles of less than 3 nm TEM average particle size (d) on the HCS. Pt/HCS-B contained more Pt0 species than Pt/HCS-P, an effect of the synthesis method. In addition, the structure of the HCS remains more ordered after BAE synthesis, compared to polyol. Regarding the catalytic activity for the Oxygen Reduction Reaction (ORR) in 0.5 M KOH, Pt/HCS-P and Pt/HCS-B showed a similar performance in terms of current density (j) at 0.9 V vs. RHE than the benchmark commercial 20 wt. % Pt/C. However, Pt/HCS-P and Pt/HCS-B demonstrated a 6 and 5-fold increase in mass catalytic activity compared to Pt/C, respectively. A positive effect of the high specific surface area of the HCS and its interactions with metal nanoparticles and electrolyte, which promoted the mass transfer, increased the performance of Pt/HCS-P and Pt/HCS-B. The high catalytic activity showed by Pt/HCS-B and Pt/HCS-P for the ORR, even with a low-Pt content, make them promising cathode nanocatalysts for Anion Exchange Membrane Fuel Cells (AEMFC).

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