Abstract

This study reveals ion exchange kinetics in hydrated calcium-alumino layered double hydroxides of the alumino-ferrite monosubstituent (AFm) subgroup. By careful analysis of solution phase (ion) concentrations and the solid phases, the rate of exchange of NO3 - for Cl- ions from the interlayer positions is studied across a range of temperature, solution compositions, and solution conditions (i.e., static and convectively mixed). Ion exchange kinetics conform to an exponential first-order reaction that follows an Arrhenius formalism. The activation energy of ion exchange is 38.2 ± 4.6 kJ/mol for exchange occurring in the thermodynamically preferred (i.e., NO3 - for Cl- ion exchange) direction and it is 1.8 times greater for the inverse less-preferred pathway. For ion exchange occurring in the favored direction NO3-AFm converts to Cl-AFm; whereas in the disfavored (less-favored) direction, the compositional change occurs in two steps with the formation of a Cl-NO3-AFm solid solution as an intermediate step; before Cl- species are exhausted and NO3-AFm forms as the product. By comparison of ion exchange rates in static and mixed solutions, transport through the Nernst diffusion layer (NDL) is identified as the rate-limiting step in ion exchange kinetics. (Graph Presented).

Original languageEnglish (US)
Pages (from-to)63-74
Number of pages12
JournalIndustrial and Engineering Chemistry Research
Volume56
Issue number1
DOIs
StatePublished - 2017

Fingerprint

Hydroxides
Calcium
Ion exchange
Kinetics
Ferrite
Ions
Solid solutions
Activation energy

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Industrial and Manufacturing Engineering

Cite this

Monovalent ion exchange kinetics of hydrated calcium-alumino layered double hydroxides. / Puerta-Falla, Guillermo; Balonis, Magdalena; Falzone, Gabriel; Bauchy, Mathieu; Neithalath, Narayanan; Sant, Gaurav.

In: Industrial and Engineering Chemistry Research, Vol. 56, No. 1, 2017, p. 63-74.

Research output: Contribution to journalArticle

Puerta-Falla, Guillermo ; Balonis, Magdalena ; Falzone, Gabriel ; Bauchy, Mathieu ; Neithalath, Narayanan ; Sant, Gaurav. / Monovalent ion exchange kinetics of hydrated calcium-alumino layered double hydroxides. In: Industrial and Engineering Chemistry Research. 2017 ; Vol. 56, No. 1. pp. 63-74.
@article{30a21f787cff49349eb28b9a61c35838,
title = "Monovalent ion exchange kinetics of hydrated calcium-alumino layered double hydroxides",
abstract = "This study reveals ion exchange kinetics in hydrated calcium-alumino layered double hydroxides of the alumino-ferrite monosubstituent (AFm) subgroup. By careful analysis of solution phase (ion) concentrations and the solid phases, the rate of exchange of NO3 - for Cl- ions from the interlayer positions is studied across a range of temperature, solution compositions, and solution conditions (i.e., static and convectively mixed). Ion exchange kinetics conform to an exponential first-order reaction that follows an Arrhenius formalism. The activation energy of ion exchange is 38.2 ± 4.6 kJ/mol for exchange occurring in the thermodynamically preferred (i.e., NO3 - for Cl- ion exchange) direction and it is 1.8 times greater for the inverse less-preferred pathway. For ion exchange occurring in the favored direction NO3-AFm converts to Cl-AFm; whereas in the disfavored (less-favored) direction, the compositional change occurs in two steps with the formation of a Cl-NO3-AFm solid solution as an intermediate step; before Cl- species are exhausted and NO3-AFm forms as the product. By comparison of ion exchange rates in static and mixed solutions, transport through the Nernst diffusion layer (NDL) is identified as the rate-limiting step in ion exchange kinetics. (Graph Presented).",
author = "Guillermo Puerta-Falla and Magdalena Balonis and Gabriel Falzone and Mathieu Bauchy and Narayanan Neithalath and Gaurav Sant",
year = "2017",
doi = "10.1021/acs.iecr.6b03474",
language = "English (US)",
volume = "56",
pages = "63--74",
journal = "Industrial and Engineering Chemistry Research",
issn = "0888-5885",
number = "1",

}

TY - JOUR

T1 - Monovalent ion exchange kinetics of hydrated calcium-alumino layered double hydroxides

AU - Puerta-Falla, Guillermo

AU - Balonis, Magdalena

AU - Falzone, Gabriel

AU - Bauchy, Mathieu

AU - Neithalath, Narayanan

AU - Sant, Gaurav

PY - 2017

Y1 - 2017

N2 - This study reveals ion exchange kinetics in hydrated calcium-alumino layered double hydroxides of the alumino-ferrite monosubstituent (AFm) subgroup. By careful analysis of solution phase (ion) concentrations and the solid phases, the rate of exchange of NO3 - for Cl- ions from the interlayer positions is studied across a range of temperature, solution compositions, and solution conditions (i.e., static and convectively mixed). Ion exchange kinetics conform to an exponential first-order reaction that follows an Arrhenius formalism. The activation energy of ion exchange is 38.2 ± 4.6 kJ/mol for exchange occurring in the thermodynamically preferred (i.e., NO3 - for Cl- ion exchange) direction and it is 1.8 times greater for the inverse less-preferred pathway. For ion exchange occurring in the favored direction NO3-AFm converts to Cl-AFm; whereas in the disfavored (less-favored) direction, the compositional change occurs in two steps with the formation of a Cl-NO3-AFm solid solution as an intermediate step; before Cl- species are exhausted and NO3-AFm forms as the product. By comparison of ion exchange rates in static and mixed solutions, transport through the Nernst diffusion layer (NDL) is identified as the rate-limiting step in ion exchange kinetics. (Graph Presented).

AB - This study reveals ion exchange kinetics in hydrated calcium-alumino layered double hydroxides of the alumino-ferrite monosubstituent (AFm) subgroup. By careful analysis of solution phase (ion) concentrations and the solid phases, the rate of exchange of NO3 - for Cl- ions from the interlayer positions is studied across a range of temperature, solution compositions, and solution conditions (i.e., static and convectively mixed). Ion exchange kinetics conform to an exponential first-order reaction that follows an Arrhenius formalism. The activation energy of ion exchange is 38.2 ± 4.6 kJ/mol for exchange occurring in the thermodynamically preferred (i.e., NO3 - for Cl- ion exchange) direction and it is 1.8 times greater for the inverse less-preferred pathway. For ion exchange occurring in the favored direction NO3-AFm converts to Cl-AFm; whereas in the disfavored (less-favored) direction, the compositional change occurs in two steps with the formation of a Cl-NO3-AFm solid solution as an intermediate step; before Cl- species are exhausted and NO3-AFm forms as the product. By comparison of ion exchange rates in static and mixed solutions, transport through the Nernst diffusion layer (NDL) is identified as the rate-limiting step in ion exchange kinetics. (Graph Presented).

UR - http://www.scopus.com/inward/record.url?scp=85017465007&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85017465007&partnerID=8YFLogxK

U2 - 10.1021/acs.iecr.6b03474

DO - 10.1021/acs.iecr.6b03474

M3 - Article

VL - 56

SP - 63

EP - 74

JO - Industrial and Engineering Chemistry Research

JF - Industrial and Engineering Chemistry Research

SN - 0888-5885

IS - 1

ER -