Synthesis, structural elucidation and carbon dioxide adsorption on Zn (II) hexacyanoferrate (II) Prussian blue analogue

Abstract

In the course of the last years hexacyanoferrates have been widely studied; even though, the adsorption properties of Zn (II) hexacyanoferrate(II) (labeled here Zn-HII) has not been thoroughly considered. In addition, soft porous crystals, i.e., adsorbents that display structural flexibility have been, as well, extensively studied, however this property has not been reported for Zn (II) hexacyanoferrate(II). In this regard, the key questions addressed here were the synthesis and structural characterization of Zn-HII together with the investigation of their low (up to 1 Bar) and high pressure (up to 30 Bar) adsorption properties, to found if these materials show structural flexibility. Then, to attain the anticipated goals, structural characterizations were made with: X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive Xray analysis (EDAX), diffuse reflectance infrared Fourier transform spectrometry (DRIFTS) and thermo-gravimetric analysis (TGA), simultaneously, with the investigation of the adsorption of carbon dioxide. As a result of the research process we concluded that the Zn-HII displayed m Fm3 space group framework. Besides, the carbon dioxide adsorption investigation demonstrated the presence of the framework expansion effect together with an extremely high adsorption heat, properties that could be useful for the use of Zn(II) hexacyanoferrate(II) as an excellent adsorbent.

Kinetic Study of CO2 Hydration by Small-Molecule Catalysts with A Second Coordination Sphere that Mimic the Effect of the Thr-199 Residue of Carbonic Anhydrase

“…(Supplementary Materials 3). All of the complexes exhibited a sharp band corresponding to the O-H bending vibration at approximately 1610 cm −1 [37]. In particular, (1) showed bands at 3254 and 3336 cm −1 , corresponding to the O-H stretching mode, while (2) showed a broad peak around 3488 cm −1 , attributable to hydrogen bonding [38,39]…”

Synthesis, Characterization, and Adsorption Properties of Nanoporous Materials

“…In Figure 4 is shown the Dubinin plot of N 2 adsorption data at 77 K in the pressure range: 0.001 < P/Po < 0.03, in a high silica commercial H-Y zeolite, precisely, the acid Y zeolite labeled CBV-720, manufactured by PQ corporation; where, adsorption data was gathered in an Autosorb-1 automatic volumetric gas adsorption system [26]; been evidently the experimental data correctly fitted by Eq. 12Recapitulating, the concrete form to made the linear Dubinin plot as represented in Figure 4 was as follows: ÀÁ n Nevertheless, this fitting process can be as well made using a non-linear regression method; in which, the fitting process is carried out with a program based on a least square procedure, allowing the calculation of the best fitting parameters of the Eq.…”

“…Prussian blue analogues (PBAs) [26,27] and nitroprussides (NPs) [28] are produced by mixing solutions of K 3 [Fe(CN) 6 ], for the synthesis of Prussian blue analogues, and Na 2 [Fe(CN) 5 NO] for the synthesis of nitroprussides with a nitrate of the corresponding metal to get the corresponding PBAs and NPs.…”

“…The X-ray Diffraction (XRD) methodology was used to determine the crystalline phases present in the natural and synthesized materials, together with the investigation of the nucleation and growth process during the synthesis of different materials to be used as adsorbents, ion exchangers and catalysts [29]. The XRD tests were carried out, at room temperature using a stage similar to an Anton Paar HTK-1200 N with an equipment similar to a Bruker D8 Advance system in a Bragg-Brentano vertical goniometer configuration, the angular measurements being made applying steps of 0.01°from 5 to 80°, using a Cu anode tube together with a Ni filter placed, prior to the detector, to eliminate Cu K α radiation the one-dimensional detector was employed [26].…”

“…If the adsorbents do not have micropores, the surface area and the outer surface area match; furthermore, the micropore volume is represented by W MP , measured in (cm 3 /g), whereas the total pore volume labeled W is the sum of the micropores and mesopore volumes [32] of the adsorbent, also measured in (cm 3 /g). Lastly, we have the pore size distribution (PSD), i.e., a plot of ∆v P ∆D p versus Dp, where Vp is the pore volume accumulated up to the pore width Dp measured in (cc-STP/g Å) [26,27]. Now it is necessary to state that cc-STP is a unit denoting the amount adsorbed, measured in cubic centimeters at standard temperature and pressure (STP), that is, 273.15 K and 760 Torr, that is, 1.01325 Â 10 5 Pa.…”