The Nanopore Inner Sphere Enhancement Effect on Cation Adsorption: Sodium, Potassium, and Calcium

Ferreira, Daniel R.; Schulthess, Cristian P.

doi:10.2136/sssaj2010.0130nps

Cited by 27 publications

(41 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These results are consistent with the adsorption data presented by Ferreira and Schulthess (2011), which showed that Na adsorbed more strongly than Ca on ZSM-5. Whereas Na easily replaced Ca, the Ca cation was only able to replace Na on the exchange complex slowly and in small quantities (Fig.…”

Section: Resultssupporting

confidence: 93%

“…Evidence in support of the NISE theory has been collected by adsorption envelopes Ferreira and Schulthess, 2011), NMR spectroscopy (Ferreira et al, 2012b), EPR spectroscopy (Ferreira et al, 2012a), and flow calorimetry (this study). All these studies involved zeolites because they have identical chemistry and fixed nanopore dimensions and, therefore, make ideal candidates for elucidating the impact of nanopore dimensions on cation adsorption.…”

Section: Discussionsupporting

confidence: 53%

“…The experiment was replicated three to five times for each zeolite solid. The pH was adjusted to these values to match the location of the adsorption plateau for Na and Ca on the various zeolites as determined by Ferreira and Schulthess (2011). The cationic charge (20 mmol c L −1 ) was also selected to match as closely as possible the experimental conditions of Ferreira and Schulthess (2011) while allowing for a constant charge balance.…”

Section: Methodsmentioning

confidence: 99%

“…The pH was adjusted to these values to match the location of the adsorption plateau for Na and Ca on the various zeolites as determined by Ferreira and Schulthess (2011). The cationic charge (20 mmol c L −1 ) was also selected to match as closely as possible the experimental conditions of Ferreira and Schulthess (2011) while allowing for a constant charge balance. It is important that the pH and cationic charge be kept constant because changes in these parameters can result in unintended calorimetric signals, as consistently observed while running experiments on the flow calorimeter (Kabengi, unpublished data, 2002).…”

Section: Methodsmentioning

confidence: 99%

“…The NISE theory was developed based on adsorption envelopes for Na, K, Ni, and Ca on various zeolites Ferreira and Schulthess, 2011). The adsorption strength was well described using adsorption envelopes, particularly by comparing the adsorption edges of competing ions.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Calorimetric Evidence in Support of the Nanopore Inner Sphere Enhancement Theory on Cation Adsorption

Ferreira

Schulthess

Kabengi

2012

Soil Science Soc of Amer J

Self Cite

View full text Add to dashboard Cite

Soil Chemistry S chulthess and Taylor (2007) proposed a new theory of cation adsorption to describe the adsorption of Na and Ni within zeolite minerals. This theory, called the nanopore inner sphere enhancement (NISE) theory, explains the unusual adsorption selectivity patterns observed for Na and Ni for Na, K, and Ca (Ferreira and. The NISE theory states that ions can dehydrate to fit into confining nanopore channels that are smaller than their hydrated diameters. In such a case, ions with lower hydration energies are more easily stabilized in their dehydrated states on adsorption than ions with higher hydration energies. Accordingly, in certain nanopore channels, monovalent ions are able to outcompete divalent ions because monovalent ions tend to have lower hydration energies than divalent ones (Collins, 1997). While hydration energy generally correlates well with the dehydration potential needed by the NISE theory, there are cases (such as Cu) where ions with high hydration energies can also dehydrate easily (Ferreira et al., 2012b).On zeolite Y, which contained the largest nanopore channels (0.74-nm limiting diameter), Ferreira and Schulthess (2011) observed that all three cations (Na, K, and Ca) adsorbed weakly and in similar amounts. On mordenite, with the smallest nanopore channels (0.26-nm limiting diameter), all three cations adsorbed strongly and in similar amounts. It is important to point out that the monovalent cations competed equally with a divalent cation at equimolar concentrations in these ion exchange reactions, which is very unusual. The most interesting results, however, The nanopore inner sphere enhancement (NISE) theory provides a new theoretical model of cation adsorption within confining nanopore channels. Inside nanopore channels, hydrated ions can dehydrate and more easily adsorb via an inner sphere mechanism. Adsorption data showed that in certain nanopores, weakly hydrated monovalent cations adsorbed more strongly than divalent cations, which tend to be strongly hydrated. Flow adsorption calorimetry is a valuable tool for directly measuring the heats of the ion exchange process and was used to measure the heats of Na and Ca exchange on three zeolite minerals: zeolite Y, mordenite, and ZSM-5. The data collected showed equal and reversible exchange reactions on mordenite but a strong endothermic Na adsorption and weak exothermic Ca adsorption on ZSM-5. On zeolite Y, the calorimetric signal was below the instrument detection limit of 5 to 7.5 mV. These differences coincide with the adsorption mechanisms and relative competitiveness predicted by the NISE theory for these two ions on the three zeolites studied. These data elucidate an exchange reaction where Ca is outcompeted by Na, which is often considered to be a weak background electrolyte.

show abstract

Section: Resultssupporting

confidence: 93%

Section: Discussionsupporting

confidence: 53%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Calorimetric Evidence in Support of the Nanopore Inner Sphere Enhancement Theory on Cation Adsorption

Ferreira

Schulthess

Kabengi

2012

Soil Science Soc of Amer J

Self Cite

View full text Add to dashboard Cite

show abstract

Enhanced Electrocatalytic Performances by Spatially Confined Aqueous Electrolytes

Zhang,

Cai,

2024

ChemistrySelect

View full text Add to dashboard Cite

Electrocatalysis is an important energy conversion and storage technology that has made significant progress in areas such as fuel cells, hydrogen production from electrolyzed water and electrochemical synthesis. In practical applications, the efficiency and stability of electrocatalytic processes remain challenging. Spatially confined (or called domain‐limited) water refers to the immobilization of water molecules in a limited region near the catalyst surface to form a specific aqueous phase environment. This domain‐limited aqueous phase environment can greatly influence the electrocatalytic efficacy by enhancing adsorption and lowering the proton transport and solvent diffusion energy barriers in the reaction. In recent years, the goal of improving electrocatalytic performance has been successfully achieved through interfacial domain‐limited, microporous domain‐limited and nanoreactor domain‐limited. Spatially domain‐limited water as a novel strategy can significantly enhance the activity and selectivity of electrocatalytic reactions, but understanding its mechanism of action remains a challenge. With a deeper understanding of domain‐limited water and further development of the technology, it is believed that it will bring greater breakthroughs and application prospects in the field of electrocatalysis.

show abstract

Nanoconfinement engineering for enchanced adsorption of carbon materials, metal–organic frameworks, mesoporous silica, MXenes and porous organic polymers: a review

Zhou

2021

Environ Chem Lett

View full text Add to dashboard Cite

The Nanopore Inner Sphere Enhancement Effect on Cation Adsorption: Sodium, Potassium, and Calcium

Cited by 27 publications

References 7 publications

Calorimetric Evidence in Support of the Nanopore Inner Sphere Enhancement Theory on Cation Adsorption

Calorimetric Evidence in Support of the Nanopore Inner Sphere Enhancement Theory on Cation Adsorption

Enhanced Electrocatalytic Performances by Spatially Confined Aqueous Electrolytes

Nanoconfinement engineering for enchanced adsorption of carbon materials, metal–organic frameworks, mesoporous silica, MXenes and porous organic polymers: a review

Contact Info

Product

Resources

About