Stanislava Andonova

Stanislava Andonova
Bulgarian Academy of Sciences | BAS · Institute of General and Inorganic Chemistry

Doctor of Philosophy

About

30
Publications
2,806
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
862
Citations
Citations since 2016
12 Research Items
682 Citations
2016201720182019202020212022050100150
2016201720182019202020212022050100150
2016201720182019202020212022050100150
2016201720182019202020212022050100150

Publications

Publications (30)
Article
Full-text available
The transition to a hydrogen economy requires the development of cost-effective methods for purifying hydrogen from CO. In this study, we explore the possibilities of Cu/ZSM-5 as an adsorbent for this purpose. Samples obtained by cation exchange from aqueous solution (AE) and solid-state exchange with CuCl (SE) were characterized by in situ EPR and...
Poster
Full-text available
Capturing carbon dioxide from large CO 2 emission sources, like power plants and steel mills, is technologically the first important stage of the CCS and CCU approaches aimed at mitigating the global warming. Nowadays, separation of CO 2 using liquid sorbents such as amine liquids is a mainstream CO 2 capture technology. This separation technique u...
Article
Potassium Nickel hexacyanoferrate Prussian Blue Analogues (K-NiFe-PBAs) offer an excellent platform for efficient CO2 capture due to their porous nature and accessible channels. Herein, the effect of Ni:K atomic ratio on the structure and the CO2 storage capacity was studied by employing K-NiFe-PBAs with Ni:K ratio of ca. 2.5 and 12. The porosity a...
Article
Full-text available
The variety of functionalities and porous structures inherent to metal-organic frameworks (MOFs) together with the facile tunability of their properties makes these materials suitable for a wide range of existing and emerging applications. Many of these applications are based on processes involving interaction of MOFs with guest molecules. To optim...
Article
Effects of H 2 /D 2 adsorption on the surface chemistry of Pt/CeO x -ZrO x /γ-Al 2 O 3 DeNO x catalyst were investigated. In-situ FTIR spectroscopy and NO x -TPD techniques were utilized to monitor changes in the surface chemistry of studied materials. Adsorption studies of CO and O 2 revealed that the Pt/Ce-Zr/Al sample, initially reduced with H 2...
Article
Surface chemistry and the nature of the adsorbed NOx species on a Pt/CeO2-ZrO2/Al2O3 catalyst were investigated by IR spectroscopy, X-ray diffraction (XRD), H2−Temperature Programmed Reduction (H2-TPR) and NOx−Temperature Programmed Desorption (NOx-TPD). Parallel studies were also carried out with benchmark samples such as: CeO2/Al2O3, ZrO2/Al2O3,...
Article
Metal-organic frameworks are promising materials for CO2 capture and their CO2 adsorption properties can be tuned by appropriate functionalization. We have recently shown that hydroxyl functionalized MIL-53(Al) materials (where part of the linkers are 2,5-dihydroxy terephthalate ligands) possess enhanced CO2 adsorption capacity at relatively low pr...
Article
The adsorption of NO2 on Pt/BaO/γAl2O3 catalyst has been investigated by micro calorimetry at atmospheric pressure, NOx storage tests and temperature-programmed desorption (TPD). The heat of adsorption of NO2 (ΔHads(NO2)) was determined over a wide range of NOx coverages, as the catalyst was exposed to 500/900 ppm NO2 in the absence/presence of 5%...
Article
Adsorption of CO2 on MIL-53(Al) and NH2-MIL-53(Al) has been studied by FTIR spectroscopy at different temperatures and equilibrium pressures. For better interpretation of the spectra ¹³CO2 was also utilized. It is established that with both samples at low coverages CO2 forms O-bonded complexes with the structural OH groups (OH...O¹²CO). These speci...
Article
Full-text available
The influence of the noble metals (Pt vs. Rh) on the NOx storage reduction performances of lean NOx trap catalysts is here investigated by transient micro-reactor flow experiments. The study indicates a different behavior during the storage in that the Rh-based catalyst showed higher storage capacity at high temperature as compared to the Pt-contai...
Article
A [Ge]FAU zeolite sample (2.36 wt. % Ge) was synthesized by a new approach comprising utilization of mother liquids instead of zeolite seeds and characterized by FTIR spectroscopy of adsorbed CO and N2 as probe molecules. A Ge-free sample with similar Al concentration was also prepared and studied for comparison. The background spectra of the H-[Ge...
Article
Full-text available
FTIR spectra of (12)CO2 and (12)CO2 + (13)CO2 mixtures adsorbed on MIL-53(Al) reveal the formation of highly symmetric dimeric (CO2)2 species connected to two structural OH groups.
Article
Full-text available
Acidity of solids is decisive for their interaction with guest molecules. One of the most used methods for measuring the acidity of surface hydroxyl groups is the hydrogen bond method based on the spectral shift of the OH stretching modes induced by the adsorption of weak bases. However, many materials of practical interest (e.g. metal organic fram...
Article
An investigation into the impact of sulfur oxide on the activity of Cu-SAPO-34 towards selective catalytic reduction of NOx by NH3 has been conducted to clarify the possible mechanism of deactivation induced by sulfur. Several reactions including NH3 storage/TPD, NO/NH3 oxidations, standard and fast SCR, as well as SCR with an NO2/NOx ratio of 75%...
Article
Addition of hydrogen significantly increases the amount of stored nitrogen oxides (NOx) over Pt/Ba/Al2O3 at 100 °C and Ag/Al2O3 between 100 and 200 °C. This increase is unique for hydrogen as reductant. A higher apparent NOx storage capacity is also observed by simultaneous reduction of NO in a selective catalytic reduction (SCR) reaction, where, h...
Article
High loaded silver/alumina (16 wt%) was found to be suitable as a temporary NOx trap under cold start, so called passive NOx storage. High amounts of NOx can be stored in the presence of H2 on this material below 200 °C and released below 400 °C under lean conditions or under rich conditions at adsorption temperature. Graphical Abstract
Article
In this study, we investigate the effect of varying copper loading in Cu-BEA on different reactions involved in the SCR mechanism. The catalysts were characterized by BET, ICP-AES, and UV–Vis. Enlarged ammonia storage was observed when increasing the copper loading mainly owing to loosely bonded NH3, but for over-exchanged samples, a new high-tempe...
Article
To obtain a better understanding of the deactivation of SCR catalysts that may be encountered due to the presence of P-containing impurities in diesel exhausts, the effects induced by P over Cu/BEA NH3-SCR catalysts were studied as functions of the temperature of poisoning and P concentration in the feed. Cu/BEA catalysts with different Cu loadings...
Article
The overall NSR operation was tested over a bimetallic Pt/Rh–BaO lean NOx trap (LNT) catalyst in the range of 473–673 K with simulated diesel exhausts and compared to monometallic 1 wt% Pt/BaO/γ-Al2O3 and 0.5 wt% Rh/BaO/γ-Al2O3 samples. The results showed the beneficial effect of the simultaneous presence of 0.5 wt% Pt and 0.25 wt% Rh on the cataly...
Article
To determine the promoting effect of Rh on the overall NOx storage and reduction (NSR) performance, the studies in the current work were directed toward investigating the storage and release ability over Rh NOx storage BaO-based catalysts compared to Pt. In terms of the metal surface dispersion and the ability of the noble metals to release oxygen...
Article
The effect of the Co addition on the structure and redox properties of Ni/γ-Al2O3 catalyst for oxidative steam reforming of ethanol (OSRE) was studied as a function of the CoO content (1–6wt%). Systematically investigations during reduction process of the oxide samples under H2 atmosphere and the oxi-reduction behaviour of the reduced catalysts und...
Article
Full-text available
In an attempt to control the surface dispersion and the mobility of BaO domains on NOx storage materials, TiO2/TiOx anchoring sites were introduced on/inside the conventional γ-Al2O3 support matrix. BaO/TiO2/Al2O3 ternary oxide materials were synthesized via two different sol−gel preparation techniques, with varying surface compositions and morphol...
Article
In an attempt to control the surface dispersion and the mobility of BaO domains on NOx storage materials, TiO2/TiOx anchoring sites were introduced on/inside the conventional γ-Al2O3 support matrix. BaO/TiO2/γ-Al2O3 ternary oxide materials were synthesized via two different sol-gel preparation techniques, with varying surface compositions and morph...
Article
Full-text available
Fe promoted NOx storage materials were synthesized in the form of FeOx/BaO/Al2O3 ternary oxides with varying BaO (8 and 20 wt %) and Fe (5 and 10 wt %) contents. Synthesized NOx storage materials were investigated via TEM, EELS, BET, FTIR, TPD, XRD, XPS, and Raman spectroscopy, and the results were compared with the conventional BaO/Al2O3 NOx stora...
Article
Full-text available
A ternary oxide-based NOx storage material in the form of BaO/TiO2/γ-Al2O3 was synthesized and characterized. Thermally induced structural changes occurring on the surfaces of the TiO2/γ-Al2O3 and BaO/TiO2/γ-Al2O3 systems were studied in a comparative manner within 300−1273 K via X-ray diffraction (XRD), Raman spectroscopy, scanning electron micros...
Article
The effect of the support γ-Al2O3 modified with CaO by deposition–precipitation method on the structure, catalytic activity and selectivity of Mo and Ni-Mo catalysts for HDS was investigated. The resistance of the catalysts to deactivation by coke formation was also investigated. The samples have been characterized by means of XRD, DRS, XPS, Al27 N...
Article
The effect of mechanical–chemical activation (MCA) of Ni(Co)–Mo catalysts, supported on γ-Al2O3 has been studied with respect to their phase composition, structure, catalytic activity and selectivity in the reaction of thiophene hydrodesulphurization (HDS). The mechanical-chemical treatment with a duration of 7 h has been accomplished with a planet...
Article
Full-text available
The effect of the amount of Nb2O5on the dispersion and reductive properties of Mo/Nb2O5-SiO2 catalysts has been studied. Addition of niobium leads to an increase of the dispersion, and the reducibility of molybdenum. A synergetic effect of niobium on the catalytic activity in hydrodesulfurization of thiophene was observed at 5.4 wt.% of Nb2O5.
Article
Full-text available
Introduction Over the past several years, the global environmental protection efforts resulted in stringent emission legislation regarding NOx emissions originating from stationary as well as mobile sources. Among the variety of approaches, the NOx storage-reduction (NSR) technology 1 is one of the most promising catalyst technologies that are capa...

Network

Cited By