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The mechanism of thermal degradation of poly(furfuryl alcohol) (PFA) deposited on the MCM-48 mesoporous silica was studied. The behaviour of the thin PFA film homogeneously dispersed on the silica surface (the material with the real PFA/MCM-48 mass ratio of 0.06) was compared to that of the 3D structure of PFA completely filling the MCM-48 channels (the material with the real PFA/MCM-48 mass ratio of 1.02). The progress of decomposition was controlled by thermogravimetry accompanied by infrared spectroscopy providing information on the composition of gaseous products evolved during the sample degradation. The thermal treatment of PFA/MCM-48 composites at various temperatures in the range of 523–1323 K enabled us to synthesize two series of PFA-derived carbon adsorbents: (1) containing the degraded PFA film supported on the mesoporous silica and (2) CMK-1 type carbon replicas, which were obtained by leaching of SiO2 from the PFA/MCM-48 composite after the previous pyrolysis. The structural and textural properties of these materials were determined by powder X-ray diffraction, DRIFT spectroscopy and low-temperature nitrogen adsorption. Furthermore, the samples were tested as adsorbents of different volatile organic compounds (VOCs). The PFA/MCM-48 materials showed the high adsorption capacity only in the removal of polar molecules, whereas CMK-1 was effective in the elimination of linear alkanes and aromatic VOCs as well.

A synthesis of metal oxide modified clays based on the hydrogel template assisted route was proposed. This novel method was verified by an intercalation of poly(acrylic acid) (PAA) into the interlayer space of montmorillonite (MT) using the in situ polymerization technique. The obtained hydrogel/clay composite with a MT/PAA mass ratio close to 1.0 exhibited an expanded layered structure and an excellent adsorption capacity for transition metal cations. These features were exploited to the modification of MT-PAA material with various amounts of Fe3+ cations by deposition at controlled pH = 2.5. The introduced Fe species favored the hydrogel burning, therefore in a subsequent step the organic template could be easily removed by calcination under oxidizing conditions at temperature protecting the clay against deep dehydroxylation. A gradual delamination of MT with an increase in the Fe content was observed after thermal treatment. This effect resulted in opening of the MT structure, manifested by a relatively high surface area and a large porosity. XRD, TEM, UV–Vis-DRS and XPS measurements exhibited that the formed α-Fe2O3 nanoparticles were highly dispersed on the exfoliated clay, which comprised a framework stabilizing the nanophase.

Poly(sodium acrylate), polyacrylamide and their copolymers were introduced into the interlayer spaces of raw montmorillonite (Mt) by in-situ polymerization. The obtained clay polymer nanocomposites (CPN) retained the layered structure. The polymers were intercalated at an intended polymer-to-clay mass ratio of 1:1. Differences in the mechanism of decomposition of samples depended on the type of polymer functional groups. The CPN were tested as adsorbents of Fe3 + ions. The highest adsorption capacity was achieved for samples containing poly(sodium acrylate), which was due to their high swelling capacity and the attraction of iron ions by carboxyl groups.

A series of hydrotalcite-like materials containing Mg 2+ /Zn 2+ and Al 3+ cations in the brucite-like sheets and carbonate or benzoate anions in the interlayer gallery was prepared by the coprecipitation method. The difference in the chemical composition of the synthesized layered double hydroxides resulted in obtaining mixed metal oxides with various phase composition (caused by different cations) as well as various crystallinity and textural parameters (caused by different anions). The Mg Zn Al oxide systems obtained from the benzoate-intercalated precursors had significantly higher crystallinity and narrower pore size distribution compared to the carbonate-modified samples. The structural and textural prop- erties of the calcined materials influenced their sorption capacities in the chromate removal from an aqueous solution at the optimal pH of 6.0. The most efficient adsorbent was obtained from the calcined magnesium–zinc–aluminum hydrotalcite-like precursor containing interlayer CO 3 2 − anions. This mate- rial exhibited high efficiency in the chromate elimination even in the presence of competitive anions (Cl − or SO 4 2 −).

The SCR of NO and NO decomposition were investigated over a V-W-O/Ti(Sn)O 2 catalyst on a Cr-Al steel monolith. The conversions of NO and NH 3 over the reduced and oxidised catalysts were determined. The higher conversion of NO than of NH 3 was observed in SCR over the reduced catalyst and very close conversions of both substrates were found over the oxidised one. The increase of the pre-reduction temperature was found to cause an increase in catalyst activity and its stability in direct NO decomposition. The surface tungsten cations substituted for vanadium ones in vanadia-like active species are considered to be responsible for the direct NO decomposition. The results of DFT calculations for the 10-pyramidal clusters: V 10 O 31 H 12 (V-V) and V 9 WO 31 H 12 (V-W) modelling (001) surfaces of vanadia and WO 3 -V 2 O 5 solid solution (s.s.) active species, respectively, show that preferable conditions for NO adsorption exist on W sites of s.s. species and that reduction causes an increase in their ability for electron back donation to the adsorbed molecule. Electron back donation is believed to be responsible for the electron structure reorganisation in the adsorbed NO molecule resulting in its decomposition. The high selectivity of NO decomposition to dinitrogen was considered to be connected with the formation of the tungsten nitrosyl complexes solely via the W-N bond.

This paper concerns the relation between surface structure of crystalline vanadia-like active species on vanadia–tungsta catalyst and their activity in the selective reduction of NO by ammonia to nitrogen. The investigations were performed for Ti–Sn-rutile-supported isopropoxy-derived catalyst. The SCR activity and surface species structure were determined for the freshly prepared catalyst, for the catalyst previously used in NO reduction by ammonia (320 ppm NO, 335 ppm NH3 and 2.35 vol% O2) at 573 K as well as for the catalyst previously annealed at 573 K in helium stream containing 2.35 vol% O2. The crystalline islands, exposing main V2O5 surface, with some tungsten atoms substituted for V-ones, were found, with XPS and FT Raman spectroscopy, to be present at the surface of the freshly prepared catalyst. A profound evolution of the active species during the catalyst use at 573 K was observed. Dissociative water adsorption on V5+OW6+ sites is discussed as mainly responsible for the catalyst activity at 473 K and that on both V5+OW6+ and V4+OW6+ sites as determining the activity at 523 K.

Poly(acrylic acid)/montmorillonite (MMT) composites with various polymer contents were synthesized by in situ polymerization technique. The structure of obtained materials was characterized by powder X-ray dif- fraction and infrared spectroscopy (FTIR). It was found that only a limited amount of hydrogel could be introduced between the clay layers. The remaining part of polymer was deposited on the external surface of clay particles. The introduction of the polymer modifier significantly increased the adsorption capacity of MMT in the elimination of $Fe^{3+}$ ions from aqueous solution. The thermal behavior of the samples before and after the $Fe^{3+}$ adsorption was examined by thermogravimetry and differential thermal analysis. Moreover, the composition of gaseous products evolved during decomposition was determined by FTIR. The mate- rials after $Fe^{3+}$ adsorption exhibited different thermal sta- bility in oxidizing atmosphere than the fresh samples. $Fe^{3+}$ cations, forming $FeO_x$ species during thermal treatment, appeared to be effective catalysts of polymer oxidation.

Polymer/layered silicate nanocomposites based on polymeric quaternary ammonium salts (ionenes) intercalated into the interlayer galleries of montmorillonite were synthesized. Zeta potential measurements were conducted to determine the amount of ionenes required to neutralize the negative charge of clay. The composition and structure of the obtained nanocomposites were examined by elemental analysis, ATR-FTIR and XRD. High dye sorption capacity was observed for the composite containing ionene 6,2.