Bartek Szyja

• PhD
• Professor at Wrocław University of Science and Technology

This paper reports for the first time a computational analysis of the redox properties of graphene-supported Ru-porphyrins as potential catalytic materials for electrochemical CO2 reduction. Density functional theory reveals that such catalytic ensembles can efficiently activate both CO2 and CH4 molecules indicating their generic utility as C1-func...

Reaction mechanisms for the catalytic hydrogenation of CO2 by faujasite-supported Ir4 clusters were studied by periodic DFT calculations. The reaction can proceed through two alternative paths. The thermodynamically favoured path results in the reduction of CO2 to CO, whereas the other, kinetically preferred channel involves CO2 hydrogenation to fo...

A computational study is presented of the cooperative effect of a small four atom Co oxide cluster supported on the TiO2 anatase (100) surface in the electrochemical water splitting reaction. Results have been obtained including explicit solvent water molecules by means of Car-Parrinello MD simulations. Reaction steps in the catalytic cycle determi...

Metal-ligand cooperative properties of a bis-N-heterocyclic carbene ruthenium CNC pincer catalyst and its activity in CO2 hydrogenation to formates were studied by DFT calculations complemented by NMR spectroscopy and kinetic measurements. The dearomatized Ru-CNC* pincer (1*) is significantly more reactive toward metal-ligand cooperative activation...

High-silica (gel Si/Al = 100) SSZ-13 membranes were prepared by hydrothermal secondary growth on the surface of [small alpha]-alumina hollow fiber supports. The membranes were evaluated for their performance in the separation of CO2 from equimolar mixtures with CH4 or N2. The maximum CO2-CH4 and CO2-N2 separation selectivities were found to be 42 a...

In this work, we present a theoretical investigation of the SrTiO3 perovskite-supported Pd catalyst in the methanol electro-oxidation reaction. In order to determine the metal–support interactions, we designed a system consisting of a Pd (100) double layer supported on one of the two possible terminations of the (100) perovskite surface. These term...

In this paper, we explore the catalytic CO2 reduction process on 13-atom bimetallic nanoclusters with icosahedron geometry. As copper and nickel atoms may be positioned in different locations and either separated into groups or uniformly distributed, the possible permutations lead to many unnecessary simulations. Thus, we have developed a machine l...

Chemia obliczeniowa jest jedną z wielu gałęzi chemii teoretycznej. Jednym z licznych zastosowań metod chemii obliczeniowej jest badanie właściwości fizykochemicznych związków, zarówno znanych, jak i jeszcze nieotrzymanych na drodze eksperymentalnej. W niniejszym artykule zostały przedstawione rezultaty badań teoretycznych 12 związków (analizowany k...

The partial oxidation reaction of CH4 led to the formation of CH3OH in the presence of Ru‐porphyrin oxo complexes (denoted as POR, POR‐O and POR‐OH where in the case of the last two, oxygen atom and the OH group were attached to the active site, respectively), in which Ru was present on different oxidation states. The simulations were performed bas...

We present the analysis of the stability of the (TiO2)n nanoclusters, where n = 2–4, supported on the Fe3O3-hematite (100) surface. The analysis is focused on the size and geometry of the nanocluster, which defines the contact with the supporting hematite surface. The aim of the work is to explore the role of the interaction within the nanocluster...

We present a DFT analysis of the role of the Cu-Ni synergistic effect for the CO2 reduction to C2H4, in comparison to the pure Cu catalyst. The analysis is focused on the thermodynamic stability of reactive intermediates along the proposed pathway of C2 species formation. We have observed that the potential needed for the reaction decreases with th...

The aim of the study was to evaluate the effect of the peptide structure (WKWK)2-KWKWK-NH2, P4 (C12)2-KKKK-NH2, P5 (KWK)2-KWWW-NH2, P6 (KK)2-KWWW-NH2 on their physicochemical properties. The thermogravimetric method (TG/DTG) was used, which made it possible to observe the course of chemical reactions and phase transformations occurring during the h...

The photochemical properties of 1,2-di(4-pyridyl)ethylene (bpe) and trans-2-(4-fluorophenyl)vinylboronic acid (fpvb) cocrystals have been investigated using complementary techniques: single-crystal X-ray diffraction, including high-pressure experiments, solid-state and solution nuclear magnetic resonance, and density functional theory calculations....

(1) Background: Depending on the type of hydrophilic polymer used, different types of hydrogels may be chemically stable or may degrade and eventually disintegrate, or dissolve upon exposure to sunlight. Many over-the-counter medications are now stored with a limited control of temperature, humidity and lighting. Therefore, in this study, the photo...

We present the development of the method for the refitting the ReaxFF parameters for a system consisting of the mixed transition metal oxides. We have tested several methods allowing to calculate the differences between the vectors of the forces acting on atoms obtained from the reference DFT simulation and the parameters-dependent ReaxFF. We concl...

We present the comparative analysis of three Zn-based sorbents for the process of sulphur removal from hot coal gas. The sorbents were prepared by a slurry impregnation of TiO2, SiO2 and Al2O3, resulting in complex, multiphase materials, with the dominant phases of Zn2TiO4, Zn2SiO4 and ZnAl2O4, respectively. We have analyzed the effect of supports...

We present the development of the method for the refitting the ReaxFF parameters for a system consisting of the mixed transition metal oxides. We have tested several methods allowing to calculate the differences between the vectors of the forces acting on atoms obtained from the reference DFT simulation and the parameters-dependent ReaxFF. We concl...

The O-H...N and O-H...O hydrogen bonds were investigated in 10-hydroxybenzo[h]quinoline (HBQ) and benzo[h]quinoline-2-methylresorcinol complex in vacuo, solvent and crystalline phases. The chosen systems contain analogous donor and acceptor moieties but differently coupled (intra- versus intermolecularly). Car–Parrinello molecular dynamics (CPMD) w...

The present study proposes an important contribution to the understanding of ionic liquid role as structure directing agent for zeolite synthesis. A series of imidazolium based ionic liquids are used for this purpose. While the anionic counterpart influences the micellar organization during the synthesis, the imidazolium cation clearly directs the...

In this work we use classical methods to develop an accurate model able to describe the interactions between the molecule of water and the hematite surface. We study the variation of the interaction energy between the water molecule and the surface regarding some geometrical aspects such as the proximity to different parts of the surface, the molec...

Intra- and inter-molecular interactions were studied in 2,3-dichloro-5,8-dihydroxy-1,4-naphthoquinone and 1,4-dihydroxy-anthraquinone to shed more light on the molecular assembly phenomena. The electronic ground and excited states features of the compounds were investigated to find structure-property dependencies. The theoretical study was carried...

The inter- and intramolecular interactions of benzo[h]quinoline and 10-hydroxybenzo[h]quinoline have been studied using quantum-chemical methods. Here, we report on results of monomeric and dimeric forms obtained on the basis of Density Functional Theory (DFT) in its classical formulation as well as using its Time-Dependent extension (TD-DFT). The...

Metal nanoparticles supported on semiconductor surfaces have been proposed as promising nanocatalyst candidates of CO2 conversion to energy carrier molecules such as formic acid or carbon monoxide, which can be used as a feedstock for fuels synthesis. This study is focused on the bimetallic Cu/Ni nanoparticles supported on the ZnO. The respective r...

We present the analysis of the indirect role of the Co doping on the electrocatalytic activity of α−Fe2O3. Upon substitution of one of the Fe atoms in the hematite surface, we have observed a promoting effect of the substitution, upon which the overpotential required for the water splitting reaction decreased in all substitution sites investigated....

New chiral tetrasubstituted aminophosphonic acid derivatives of hexahydroquinoxalin-2(1H)-one were synthesised via highly diastereoselective hydrophosphonylation of the corresponding imines with tris(trimethylsilyl) phosphite as phosphorus nucleophile. High asymmetric induction, good yields, mild...

Typical zeolite synthesis reaction mixture involves framework atom source, solvent, mineraliser, and structure directing agent. However, these components often have a dual function, and their impact on the nucleation/crystallization process is difficult to be established straightforwardly. The present study deals with the structure directing effect...

Mesoporous and nanostructured zeolite-based catalysts experience prolonged lifetimes due to increased mass transfer and reduced micropore obstruction by coke formation as compared to their bulky microporous counterparts. Diquater-nary ammonium structure-directing agents (SDA) can be used to synthesize hierarchical MFI sheet-like and MEL-needle like...

We present the analysis of the role of the substitutional doping on the electronicstructure of Fe2O3– hematite – (110) surface. The presence of a heteroatom in different crystallographic positions in the surface layer of hematite influences the band structure– additional donor or acceptor states appear in the band gap depending on the typeand charg...

Zeolites are natural or synthetic materials with porous chemical structures that are valuable due to their absorptive and catalytic qualities. Metal-Organic Frameworks (MOFs) are manmade organometallic polymers with similar porous structures. This introductory book, with contributions from top-class researchers from all around the world, examines t...

The Cover Feature shows a representation of the Ru‐porphyrin‐based artificial leaf, with a graphene sheet serving as a support. In their Full Paper, K. Szkaradek et al. describe the pathways of electrocatalytic CO2 hydrogenation to HCOOH, CH3OH and CH4. The results demonstrate the crucial role of the overpotential on the selectivity of the process....

This work presents the theoretical activity of the graphene supported Ru‐CNC pincer complexes and Ru‐porphyrin in the electrocatalytic CO2 hydrogenation to FA and reduction to CO. The pathways with the formate and carboxyl intermediates are investigated to estimate the preferred pathway and the overpotential needed to overcome the thermodynamic lim...

Thanks to a rapid increase in the computational power of modern CPUs, computational methods have become a standard tool for the investigation of physico-chemical phenomena in many areas of chemistry and technology. The area of porous frameworks, such as zeolites, metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs), is not differe...

Hypothesis: In photorheological fluids, subtle molecular changes caused by light lead to abrupt macroscopic alterations. Upon UV irradiation of an aqueous cetyltrimethylammonium bromide (CTAB) and trans-ortho-methoxycinnamic acid (trans-OMCA) solution, for instance, the viscosity drops over orders of magnitude. Multiscale modeling allows to elucid...

The study is focused on the CO2 decomposition on small (6-, 7-, 8- and 13-atomic) Cu clusters. The mechanism of the reaction was investigated by means of the molecular dynamics approach on the DFT level of theory. We have determined that there are two possible transition-state structures for the C–O bond dissociation—one where the reaction occurs o...

The TiO2/beta-SiC nanocomposites containing 0-25 wt. % of beta-SiC were synthesized by the sol-gel method and tested in the photodegradation of methylene blue and methyl orange water solutions. With the increase of SiC content, only a slight decrease in energy band gap was observed (3.19-3.12 eV), together with significant increase of the surface a...

In applying a multi-scale spectrospic and computational approach, we demonstrate that the synthesis of stacked zeolite Silicalite-1 nanosheets, in the presence of a long-tail diquarnary ammonium salt surfactant, proceeds through a pre-organised phase in the condensed state. In-situ Small-Angle X-ray Scattering, coupled to Paracrystalline Theory, an...

Scientific Reports 6 : Article number: 23199 10.1038/srep23199 ; published online: 16 March 2016 ; updated: 20 June 2016 The Acknowledgements section in this Article is incomplete.

Recent synthetic efforts aimed at reconstructing the beginning of life on our planet point at the plausibility of scenarios fueled by extraterrestrial energy sources. In the current work we show that beyond nucleobases the sugar components of the first informational polymers can be synthesized in this way. We demonstrate that a laser-induced high-e...

The water-splitting process on electrochemical cells is studied with focus on the energetics of the oxygen evolution reaction at the TiO2-based anodes. New reaction mechanisms are proposed that lead to the decomposition of water molecules on TiO2 clusters. The oxygen evolution reaction at the anode is investigated using electronic structure calcula...

The water electrolysis process requires the use of the proper catalyst in order to lower the overpotential needed to overcome the thermodynamic limitations of the process. The study presented in the article makes use of the MD simulation with explicit solvent to evaluate the relative stability of the particular intermediates in the electrocatalytic...

We have investigated the adsorption of CO2 molecules inside the EMT, SAO, SBS, SBT and IWS zeolites with respect to the influence of the Ir4 clusters on the adsorption capabilities of these materials. We have determined that the capabilities of CO2 adsorption depend on the combined effect of the framework topology and the position of the Ir4 cluste...

Density functional theory (DFT) based molecular dynamics simulations have been performed of a 1,4-benzenedithiol molecule attached to two gold electrodes. To model the mechanical manipulation in typical break junction and atomic force microscopy experiments, the distance between two electrodes was incrementally increased up to the rupture point. Fo...

The stability of step-edge-type surface sites on cobalt nanoparticles is investigated for particles of increasing size of 1.8, 2.2, and 2.9 nm, that contain 321, 603, and 1157 atoms, respectively. The stability of surface configurations is probed by analyzing the kinetics of the disappearance of step-edge sites as a function of temperature using Re...

We have studied the adsorption of CO2 molecules inside the pores of faujasite zeolite and evaluated the influence of the Ir4 clusters on the intensity of the adsorption. The force field designed for CO2 adsorption in zeolites has been extended with the parameters for the CO2/Ir4 interactions, taking the Density Functional Theory (DFT) energies as a...

Mechanochemically facilitated retro [2 + 2] cycloaddition of four-membered ketene dimer rings was investigated using density functional theory and Ultrasound induced scission experiments. The results reveal that, in contrast to many other mechanochemical processes, the activation energy for mechanochemical ring-opening of cyclobutane-1,3-diones inc...

The formation of formamide trimers was simulated using Car-Parrinello molecular dynamics. A variety of different initial setups were compared to study the effects of spatial arrangement, concentration, and temperature on the trimer product distribution. A total of nine different trimer species were obtained by simulation. Although a triangular init...

Ab initio molecular dynamics simulations have been performed of a gold—1,4-benzenedithiol (BDT)—gold nanojunction under mechanical stress. For three different pulling rates between 10 and 40 m s-1, it is found that the nanowire always ruptures between the second and third Au atom from the thiol sulfur. Larger rupture forces and longer extensions ar...

This study is the analysis of the adsorption process of the CO2 molecule on the cationic sites of the DOH zeolite. Based on the DFT method, we have been able to identify several adsorption sites containing extra-framework cations and evaluate the value of the adsorption energy with respect to the distance from the adsorption site. The zinc cation h...

This study reports the use of 1-butyl-3-methyl imidazolium methanesulfonate ionic liquid as a template in the synthesis of zeolites. It is found that the silicon source determines the formation of beta (BEA), mordenite framework inverted (MFI), or analcime (ANA) zeolites. Depending on this source, different preorganized complexes are obtained that...

The dual template synthesis of zeolite SSZ-13 by use of trimethyl-adamantanammonium hydroxide and a diquaternary-ammonium mesoporogen induces considerable mesoporosity without impeding zeolite microporosity. The strongly improved accessibility of Brønsted sites in mesoporous SSZ-13 increases its stability during application as an acid catalyst in t...

We present a method for studying mechanochemical bond breaking (i.e. induced by the external mechanical force) by means of Molecular Dynamics simulations. The method is based on application of artificial force acting in desired direction particular atoms, which is known as the Steered Molecular Dynamics method. We have applied SMD formalism to the...

We present a combined DFT and MP2 level molecular modeling study relevant for the early stage of the synthesis of the MFI and MEL zeolite structures. We have carried out a series of DFT molecular dynamics simulations, in order to study the relative stability of the silicate oligomer precursors taking part in the synthesis process. Based on computed...

Mechanochemical scission of supramolecular polymer complexes by ultrasound is investigated using viscosity measurements and molecular dynamics (MD) simulations combined with constrained geometry optimization (COGEF) calculations. The supramolecular polymers used in this study consist of a poly(tetrahydrofuran) (PTHF) backbone that contains a silver...

Ti- and Al-containing MCM-41 materials, with a Si/M (M=Al(Ti)) molar ratio equal to 8, were used as supports for preparing NiMo HDS catalysts. On the surface of the MCM-41 based catalysts, agglomerations of the Mo oxo-species were observed. The incorporation of Ti and Al into the silica structure visibly enhanced the interactions between NiMo oxide...

We present a retro-analysis of the zeolite assembly process by the decomposition of the frameworks of MFI and MEL type zeolites. We propose structures of the building units and the intermediates of the increasing complexity and the corresponding reactions that are necessary to accomplish the assembly process. The proposed intermediate structures ar...

Two enantiomeric configurations of the Si33 precursors. Left: Shape of the precursor's initial channel is intact when one of the propyl groups of TPA is inside. Right: In absence of TPA, methyl group of TMA is too small, and the structure of the precursor collapses. Snapshot of Molecular Dynamics simulation of TPA in between two Si33 precursors. Pr...

In this paper we have applied the molecular dynamics simulations in order to analyse the role of the structure directing tetrapropylammonium ions in the aggregation process that leads to silicalite formation. We address the specific question of how the interactions between silica precursor species and tetrapropylammonium ions/water evolve during th...

Zeolite synthesis is driven by structure-directing agents, such as tetrapropyl ammonium ions (TPA+) for Silicalite-1 and ZSM-5. However, the guiding role of these organic templates in the complex assembly to highly ordered frameworks remains unclear, limiting the prospects for advanced material synthesis. In this work, both static ab initio and dyn...

The Grand Canonical Monte Carlo method was used to analyse the phenomenon of adsorption of aromatic compounds (i.e. phenol, toluene, benzoic acid and salicylic acid) on the surface of the titania-silica (TiO2/SiO2) catalyst. We found that different types of interactions play important roles in the adsorption of molecules having polar and non-polar...

Molecular modeling was used to analyze the phenomena involved in the sorption of hydrocarbons by the Pt/Al2O3 reforming catalyst. The interactions between the atoms of the catalyst structure and the molecules of the model reforming compounds were described in terms of the universal forcefield. Making use of the GCMC algorithms, the adsorption isoth...

The Grand Canonical Monte-Carlo (GCMC) method has been used to carry out simulations of the adsorption of n-heptane in models of naphtha-reforming catalysts. Models used in the study differed in the number and distribution of metal atoms—Pt and Sn. The number of adsorbed n-heptane molecules grows linearly with increasing number of metal atoms. The...

Molecular modeling methods (molecular dynamics and forced diffusion) were used for analyzing the phenomenon of C7 hydrocarbons diffusion in microporous materials. Models of zeolites (ZSM-5 and faujasite), aluminum oxide (support) and aluminum oxide with Pt atoms (catalyst of the dehydrocyclization reaction) were adopted as adsorbents. In both zeoli...

The molecular modeling method refered to in the literature as Grand Canonical Monte Carlo was used to analyze the phenomenon of n-heptane adsorption on the Pt/gamma-Al(2)O(3) catalyst. In order to describe relevant interactions, use was made of the forcefield methods (UFF and CVFF). With the conditions adopted for the purpose of the study, Pt was f...

Molecular modeling was used to analyze the adsorption of hydrocarbons on two zeolites: silicalite and faujasite, and on the Pt/γ-Al2O3 catalyst. With the application of three methods it was possible (a) to find the potential sites of adsorption (docking method), (b) to plot the adsorption isotherms (Monte Carlo sorption), and (c) to establish the v...

The use of methods dealt with in computational chemistry for the design of efficient catalysts has become increasingly frequent. In our study, molecular modeling methods were used to find the catalytic sites of a Pt-Sn/γ-Al2O3 catalyst. Five different catalyst models including one support model were constructed. With the docking method, the most pr...

The behavior of the benzene--Pt--Sn/-Al2O3 catalytic system was simulated with the software Cerius2 from Accelrys Inc. The Grand Canonical Monte Carlo (GCMC) method was used to assess the adsorption isotherms under conditions of constant pressure and an equilibrium number of benzene molecules. With the results of GCMC simulation it was possible to...

This is an analysis of the diffusion and adsorption of the model reagents involved in the reforming process (heptane, methylcyclohexane and toluene) in the support (gamma-Al2O3) and catalyst (Pt/gamma-Al2O3) made use of in this process. Since the properties of these catalytic systems are influenced by the interactions between the atoms of the catal...

The physical nature of the catalytic activity of Si→Al substitutions in ZMS-5 zeolite has been investigated for propylene protonation reaction using hybrid variation–perturbation decomposition of intermolecular interaction energy. The differential transition state stabilization energy is dominated by long range electrostatic multipole term, whereas...