1H and 23Na MAS NMR spectroscopy of cationic species in CO2 selective alkaline earth metal porous silicoaluminophosphates prepared via liquid and solid state ion exchange

pH‐Specific Halide‐Dependent Materials from ZrIV/Hydroxycarboxylic Acid/Aromatic Chelator Reactivity: Architecture–Lattice Dimensionality and Spectroscopic Fingerprint Relations

“…The resonances at δ = 3.3–3.7 and 4.8–5.2 ppm could be assigned to the hydrogen atoms of the methylene and hydroxycarboxylato‐bearing carbon groups of the malato ligands, respectively 37. The signals at lower fields could be attributed to a) the presence of water molecules, and b) hydrogen‐bonds reflecting the presence of ammonium counter ions interacting with water molecules in the lattice 38,39…”

Removal of Carbon Dioxide from Light Gas Mixtures using a Porous Strontium(II) Silicoaluminophosphate Fixed Bed: Closed Volume and Portable Applications

“…One adsorbent that has shown promising results during equilibrium adsorption measurements of CO 2 is a strontium(II), ion-exchanged silicoaluminophosphate (Sr 2+ -SAPO-34) (16)(17)(18)(19). SAPO-34 is a crystalline porous material with the framework characteristics of the natural zeolite Chabazite and, like all SAPOs, is formed by tetrahedrally coordinated silicon, aluminum, phosphorus, and oxygen atoms.…”

“…These species, mostly Na + and H + in SAPO-34, are products of the hydrothermal synthesis and calcination of the structure directing-agent and can be readily exchanged by other metal cations, changing the net electronic charge and atomic radii, and therefore, affecting the field-gradient quadrupole contribution to the total adsorption energy (2). A thorough discussion on the structural, morphology, textural, and adsorption properties of Sr 2+ -SAPO-34 is available elsewhere (16)(17)(18)(19)23).…”