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Shchukarev, Andrey
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Publications (10 of 136) Show all publications
Li, M.-B., Posevins, D., Gustafson, K. P. J., Tai, C.-W., Shchukarev, A., Qiu, Y. & Backvall, J.-E. (2019). Diastereoselective Cyclobutenol Synthesis: A Heterogeneous Palladium-Catalyzed Oxidative Carbocyclization-Borylation of Enallenols. Chemistry - A European Journal, 25(1), 210-215
Open this publication in new window or tab >>Diastereoselective Cyclobutenol Synthesis: A Heterogeneous Palladium-Catalyzed Oxidative Carbocyclization-Borylation of Enallenols
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2019 (English)In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 25, no 1, p. 210-215Article in journal (Refereed) Published
Abstract [en]

A highly selective and efficient oxidative carbocyclization/borylation of enallenols catalyzed by palladium immobilized on amino-functionalized siliceous mesocellular foam (Pd-AmP-MCF) was developed for diastereoselective cyclobutenol synthesis. The heterogeneous palladium catalyst can be recovered and recycled without any observed loss of activity or selectivity. The high diastereoselectivity of the reaction is proposed to originate from a directing effect of the enallenol hydroxyl group. Optically pure cyclobutenol synthesis was achieved by the heterogeneous strategy by using chiral enallenol obtained from kinetic resolution.

Place, publisher, year, edition, pages
Wiley-VCH Verlagsgesellschaft, 2019
Keywords
cyclobutenols, diastereoselectivity, enallenols, heterogeneous catalysis, oxidative carbocyclization, palladium
National Category
Organic Chemistry
Identifiers
urn:nbn:se:umu:diva-155638 (URN)10.1002/chem.201805118 (DOI)000454705500025 ()30307089 (PubMedID)
Funder
EU, European Research Council, ERC AdG 247014Swedish Research Council, 2016-03897Berzelii Centre EXSELENTKnut and Alice Wallenberg Foundation
Available from: 2019-01-25 Created: 2019-01-25 Last updated: 2019-01-25Bibliographically approved
Cano, A., Rodríguez-Hernández, J., Shchukarev, A. & Reguera, E. (2019). Intercalation of pyrazine in layered copper nitroprusside: Synthesis, crystal structure and XPS study. Journal of Solid State Chemistry, 273, 1-10
Open this publication in new window or tab >>Intercalation of pyrazine in layered copper nitroprusside: Synthesis, crystal structure and XPS study
2019 (English)In: Journal of Solid State Chemistry, ISSN 0022-4596, E-ISSN 1095-726X, Vol. 273, p. 1-10Article in journal (Refereed) In press
Abstract [en]

Hybrid inorganic–organic solids form an interesting family of functional materials, where their functionalities are determined by both, the inorganic and organic building blocks. This study reports the intercalation of pyrazine in 2D copper nitroprusside, the crystal structure of the resulting hybrid solid and explores the scope of cryogenic X-ray photoelectron spectroscopy (XPS) to shed light on its electronic structure. In this material, the pyrazine molecule appears coordinated to Cu atoms from neighboring layers, to form the columns in the resulting 3D porous framework. Its crystal structure was solved and refined from the corresponding XRD powder pattern. XPS data, recorded under cryogenic conditions, provided fine details on the electronic structure of this hybrid solid. The binding energy values for the ligand atoms and the involved metals show a definite correlation with the structural data and FT-IR spectra. When XPS spectra were recorded at room temperature, a significant sample decomposition was observed. Three possible mechanisms for the sample damage during the XPS experiment are considered. The hybrid material under study is representative of a wide series of nanoporous solids obtained by intercalation of organic pillars between 2D inorganic solids.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Hybrid inorganic-organic solid, Cryo-XPS, Sample degradation, Electronic and crystal structure, Transition metal nitroprussides, Pyrazine intercalation
National Category
Materials Chemistry
Identifiers
urn:nbn:se:umu:diva-157021 (URN)10.1016/j.jssc.2019.02.015 (DOI)2-s2.0-85061800990 (Scopus ID)
Available from: 2019-03-06 Created: 2019-03-06 Last updated: 2019-03-07
Nuri, A., Mansoori, Y., Bezaatpour, A., Shchukarev, A. & Mikkola, J.-P. (2019). Magnetic Mesoporous SBA-15 Functionalized with a NHC Pd(II) Complex: An Efficient and Recoverable Nanocatalyst for Hiyama Reaction. ChemistrySelect, 4(5), 1820-1829
Open this publication in new window or tab >>Magnetic Mesoporous SBA-15 Functionalized with a NHC Pd(II) Complex: An Efficient and Recoverable Nanocatalyst for Hiyama Reaction
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2019 (English)In: ChemistrySelect, ISSN 2365-6549, Vol. 4, no 5, p. 1820-1829Article in journal (Refereed) Published
Abstract [en]

Magnetite nanoparticles (MNPs) were covered by a silica shell and then embedded into mesoporous silica (SBA‐15). Magnetic mesoporous silica (Fe3O4@SiO2‐SBA) was then reacted with 3‐chloropropyltriethoxysilane (CPTS), sodium salt of imidazole and 2‐bromopyridine to give Fe3O4@SiO2‐SBA functionalized with 3‐(pyridin‐2‐yl)‐1H‐imidazol‐3‐ium‐propyl (PIP) as a supported pincer ligand for Pd(II). The functionalized magnetic mesoporous silica were then treated with t‐BuOK at −80 °C in THF and then reacted with [PdCl2(SMe2)2] to give supported Pd(II)‐carbene complex containing C,N‐bidentate ligand. The chloride ions were then exchanged by bromide ions using a NaBr solution of diethylether/acetone mixture. The prepared catalyst was characterized with, FT‐IR, thermo gravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), Brunauer–Emmett–Teller surface area measurement (SBET), energy dispersive X‐ray analysis (EDX) and wide angle X‐ray diffraction spectroscopy (XRD). The prepared magnetic catalyst was effectively used in the coupling reaction of triethoxyphenylsilane with aryl halides (Hiyama reaction) in the presence of a base. The reaction parameters such as solvents, amount of catalyst, base and temperature were optimized. The catalyst was then magnetically decanted, washed, and reused several times.

Keywords
Carbene-pyridine Pd(II) complex, Heterogeneous catalyst, Hiyama reaction, Magnetic mesoporous nanoparticles
National Category
Materials Chemistry Physical Chemistry
Identifiers
urn:nbn:se:umu:diva-156875 (URN)10.1002/slct.201803798 (DOI)000458164500037 ()
Available from: 2019-03-11 Created: 2019-03-11 Last updated: 2019-03-11Bibliographically approved
Masoud, T., Mehran, G. & Shchukarev, A. (2018). A comparison between two Pd‐Ni catalysts supported on two different supports toward Suzuki‐Miyaura coupling reaction. Paper presented at 2018/05/14. Applied organometallic chemistry, 32(5), Article ID e4338.
Open this publication in new window or tab >>A comparison between two Pd‐Ni catalysts supported on two different supports toward Suzuki‐Miyaura coupling reaction
2018 (English)In: Applied organometallic chemistry, ISSN 0268-2605, E-ISSN 1099-0739, Vol. 32, no 5, article id e4338Article in journal (Refereed) Published
Abstract [en]

When a single metal fails to promote an efficient Suzuki?Miyaura coupling reaction at ambient temperature, the synergistic cooperation of two distinct metals might improve the reaction. To examine the synergistic effect of palladium and nickel for catalyzing Suzuki coupling reaction, g?C3N4 supported metal nanoparticles of PdO, NiO and Pd?PdO?NiO were prepared, characterized and their catalytic activities evaluated over different aryl halides at room temperature and 78 °C. The morphological characterization of Pd?PdO?NiO/g?C3N4 demonstrated that the bimetallic particles were uniformly dispersed over the g?C3N4 layers with diameters ranging from 3.5?7.7 nm. XPS analysis showed that nanoparticles of Pd?PdO?NiO consisted of Pd(II), Pd(0) and Ni(II) sites. The experiments performed on the catalytic activity of Pd?PdO?NiO/g?C3N4 showed that the prepared catalyst demonstrated an efficient activity without using toxic solvents.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2018
Keywords
graphitic carbon nitride, green chemistry, heterogeneous catalyst, Pd‐PdO‐NiO nanoparticles, Suzuki coupling reaction
National Category
Organic Chemistry
Identifiers
urn:nbn:se:umu:diva-147672 (URN)10.1002/aoc.4338 (DOI)000430461300027 ()2-s2.0-85044292758 (Scopus ID)
Conference
2018/05/14
Available from: 2018-05-14 Created: 2018-05-14 Last updated: 2018-10-29Bibliographically approved
Yu, C., Boily, J.-F., Shchukarev, A., Drake, H., Song, Z., Hogmalm, K. J. & Åström, M. E. (2018). A cryogenic XPS study of Ce fixation on nanosized manganite and vernadite: Interfacial reactions and effects of fulvic acid complexation. Chemical Geology, 483, 304-311
Open this publication in new window or tab >>A cryogenic XPS study of Ce fixation on nanosized manganite and vernadite: Interfacial reactions and effects of fulvic acid complexation
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2018 (English)In: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 483, p. 304-311Article in journal (Refereed) Published
Abstract [en]

This study investigated interfacial reactions between aqueous Ce(III) and two synthetic nanosized Mn (hydr-)oxides (manganite: γ-MnOOH, and vernadite: δ-MnO2) in the absence and presence of Nordic Lake fulvic acid (NLFA) at circumneutral pH by batch experiments and cryogenic X-ray photoelectron spectroscopy (XPS). The surfaces of manganite and vernadite were negatively charged (XPS-derived loadings of (Na + K)/Cl > 1) and loaded with 0.42–4.33 Ce ions nm−2. Manganite stabilized Ce-oxidation states almost identical to those for vernadite (approximately 75% Ce(IV) and 25% Ce(III)), providing the first experimental evidence that also a Mn(III) phase (manganite) can act as an important scavenger for Ce(IV) and thus, contribute to the decoupling of Ce from its neighboring rare earth elements and the development of Ce anomaly. In contrast, when exposed to Ce(III)-NLFA complexes, the oxidation of Ce by these two Mn (hydr-)oxides was strongly suppressed, suggesting that the formation of Ce(III) complexes with fulvic acid can stabilize Ce(III) even in the presence of oxidative Mn-oxide surfaces. The experiments also showed that Ce(III) complexed with excess NLFA was nearly completely removed, pointing to a strong preferential sorption of Ce(III)-complexed NLFA over free NLFA. This finding suggests that the Ce(III)-NLFA complexes were most likely sorbed by their cation side, i.e. Ce(III) bridging between oxide groups on the Mn (hydr-)oxides and negatively-charged functional groups in NLFA. Hence, Ce(III) was in direct contact with the oxidative manganite and vernadite but despite that not oxidized. An implication is that in organic-rich environments there may be an absence of Ce(IV) and Ce anomaly despite otherwise favorable conditions for Ce(III) oxidation.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Cryogenic XPS, Manganite, Vernadite, Oxidative scavenging, Ce anomaly
National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:umu:diva-146721 (URN)10.1016/j.chemgeo.2018.02.033 (DOI)000429492300027 ()2-s2.0-85042905870 (Scopus ID)
Available from: 2018-04-18 Created: 2018-04-18 Last updated: 2018-06-13Bibliographically approved
Taheri, M., Ghiaci, M. & Shchukarev, A. (2018). Cross-linked chitosan with a dicationic ionic liquid as a recyclable biopolymer-supported catalyst for cycloaddition of carbon dioxide with epoxides into cyclic carbonates. New Journal of Chemistry, 42(1), 587-597
Open this publication in new window or tab >>Cross-linked chitosan with a dicationic ionic liquid as a recyclable biopolymer-supported catalyst for cycloaddition of carbon dioxide with epoxides into cyclic carbonates
2018 (English)In: New Journal of Chemistry, ISSN 1144-0546, E-ISSN 1369-9261, Vol. 42, no 1, p. 587-597Article in journal (Refereed) Published
Abstract [en]

Development of eco-friendly, desirable and reusable catalysts particularly for reactions in regard to carbon dioxide fixation is still attractive in academic and industrial sectors. In this study, a dicationic ionic liquid was anchored to a cheap biopolymer, i.e., chitosan and the prepared hybrid composite was used in the cycloaddition reaction of CO2 with various epoxides for preparing five-membered cyclic carbonates under solvent-free conditions in high yield and selectivity without the addition any metal co-catalyst. The catalyst was characterized by 1H and 13C NMR, FTIR, UV-vis, XPS, TG, FESEM, and BET techniques. The catalyst was recovered and recycled at least five times without losing its activity and selectivity. Moreover, it has been demonstrated that chitosan through hydrogen bonding, coordination of amine groups with CO2 and also loosely bonded bromide ion to imidazolium ion have synergistic effects on the yield and selectivity of cyclic carbonates under optimum conditions. On the basis of the obtained results, a feasible mechanism was proposed for the reaction.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2018
National Category
Chemical Sciences
Identifiers
urn:nbn:se:umu:diva-143752 (URN)10.1039/C7NJ03665E (DOI)000418369000063 ()
Available from: 2018-01-08 Created: 2018-01-08 Last updated: 2018-06-09Bibliographically approved
Kwong, W. L., Lee, C. C., Shchukarev, A., Björn, E. & Messinger, J. (2018). High-performance iron (III) oxide electrocatalyst for water oxidation in strongly acidic media. Journal of Catalysis, 365, 29-35
Open this publication in new window or tab >>High-performance iron (III) oxide electrocatalyst for water oxidation in strongly acidic media
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2018 (English)In: Journal of Catalysis, ISSN 0021-9517, E-ISSN 1090-2694, Vol. 365, p. 29-35Article in journal (Refereed) Published
Abstract [en]

Stable and efficient oxygen evolution reaction (OER) catalysts for the oxidation of water to dioxygen in highly acidic media are currently limited to expensive noble metal (Ir and Ru) oxides since presently known OER catalysts made of inexpensive earth-abundant materials generally suffer anodic corrosion at low pH. In this study, we report that a mixed-polymorph film comprising maghemite and hematite, prepared using spray pyrolysis deposition followed by low-temperature annealing, showed a sustained OER rate (>24 h) corresponding to a current density of 10 mA cm−2 at an initial overpotential of 650 mV, with a Tafel slope of only 56 mV dec−1 and near-100% Faradaic efficiency in 0.5 M H2SO4 (pH 0.3). This performance is remarkable, since iron (III) oxide films comprising only maghemite were found to exhibit a comparable intrinsic activity, but considerably lower stability for OER, while films of pure hematite were OER-inactive. These results are explained by the differences in the polymorph crystal structures, which cause different electrical conductivity and surface interactions with water molecules and protons. Our findings not only reveal the potential of iron (III) oxide as acid-stable OER catalyst, but also highlight the important yet hitherto largely unexplored effect of crystal polymorphism on electrocatalytic OER performance.

Place, publisher, year, edition, pages
Academic Press, 2018
Keywords
Artificial photosynthesis, Water oxidation, Oxygen evolution reaction, Acidic electrolyte, Iron oxide
National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:umu:diva-150224 (URN)10.1016/j.jcat.2018.06.018 (DOI)000442976400005 ()
Funder
Knut and Alice Wallenberg Foundation
Available from: 2018-07-19 Created: 2018-07-19 Last updated: 2018-09-21Bibliographically approved
Annamalai, A., Sandström, R., Gracia-Espino, E., Boulanger, N., Boily, J.-F., Mühlbacher, I., . . . Wågberg, T. (2018). Influence of Sb5+ as a Double Donor on Hematite (Fe3+) Photoanodes for Surface-Enhanced Photoelectrochemical Water Oxidation. ACS Applied Materials and Interfaces, 10(19), 16467-16473
Open this publication in new window or tab >>Influence of Sb5+ as a Double Donor on Hematite (Fe3+) Photoanodes for Surface-Enhanced Photoelectrochemical Water Oxidation
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2018 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 19, p. 16467-16473Article in journal (Refereed) Published
Abstract [en]

To exploit the full potential of hematite (α-Fe2O3) as an efficient photoanode for water oxidation, the redox processes occurring at the Fe2O3/electrolyte interface need to be studied in greater detail. Ex situ doping is an excellent technique to introduce dopants onto the photoanode surface and to modify the photoanode/electrolyte interface. In this context, we selected antimony (Sb5+) as the ex situ dopant because it is an effective electron donor and reduces recombination effects and concurrently utilize the possibility to tuning the surface charge and wettability. In the presence of Sb5+ states in Sb-doped Fe2O3 photoanodes, as confirmed by X-ray photoelectron spectroscopy, we observed a 10-fold increase in carrier concentration (1.1 × 1020 vs 1.3 × 1019 cm–3) and decreased photoanode/electrolyte charge transfer resistance (∼990 vs ∼3700 Ω). Furthermore, a broad range of surface characterization techniques such as Fourier-transform infrared spectroscopy, ζ-potential, and contact angle measurements reveal that changes in the surface hydroxyl groups following the ex situ doping also have an effect on the water splitting capability. Theoretical calculations suggest that Sb5+ can activate multiple Fe3+ ions simultaneously, in addition to increasing the surface charge and enhancing the electron/hole transport properties. To a greater extent, the Sb5+- surface-doped determines the interfacial properties of electrochemical charge transfer, leading to an efficient water oxidation mechanism.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
Keywords
hematite, ex situ doping, Fe2O3-Sb, water splitting, Sb5+, Fe3+, surface charge, double donors
National Category
Materials Chemistry
Identifiers
urn:nbn:se:umu:diva-148990 (URN)10.1021/acsami.8b02147 (DOI)000432753800027 ()29663796 (PubMedID)2-s2.0-85046257587 (Scopus ID)
Funder
Swedish Research Council, 2017-04862Carl Tryggers foundation , CTS-16-161Swedish Energy Agency, 45419-1
Available from: 2018-06-14 Created: 2018-06-14 Last updated: 2018-06-19Bibliographically approved
Trubetskaya, A., Hofmann Larsen, F., Shchukarev, A., Ståhl, K. & Umeki, K. (2018). Potassium and soot interaction in fast biomass pyrolysis at high temperatures. Fuel, 225, 89-94
Open this publication in new window or tab >>Potassium and soot interaction in fast biomass pyrolysis at high temperatures
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2018 (English)In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 225, p. 89-94Article in journal (Refereed) Published
Abstract [en]

This study aims to investigate the interaction between potassium and carbonaceous matrix of soot produced from wood and herbaceous biomass pyrolysis at high heating rates at 1250°C in a drop tube reactor. The influence of soot carbon chemistry and potassium content in the original biomass on the CO2 reactivity was studied by thermogravimetric analysis. The XPS results showed that potassium incorporation with oxygen-containing surface groups in the soot matrix did not occur during high temperature pyrolysis. The potassium was mostly found as water-soluble salts such as KCl, KOH, KHCO3 and K2CO3 in herbaceous biomass soot. The low ash-containing pinewood soot was less reactive than the potassium rich herbaceous biomass soot, indicating a dominating role of potassium on the soot reactivity. However, the catalytic effect of potassium on the reactivity remained the same after a certain potassium amount was incorporated in the soot matrix during pyrolysis. Raman spectroscopy results showed that the carbon chemistry of biomass soot also affected the CO2 reactivity. The less reactive pinewood soot was more graphitic than herbaceous biomass soot samples with the disordered carbon structure.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
soot, potassium, biomass, fast pyrolysis, CO2 reactivity
National Category
Chemical Process Engineering
Identifiers
urn:nbn:se:umu:diva-146122 (URN)10.1016/j.fuel.2018.03.140 (DOI)000432922400011 ()
Available from: 2018-04-02 Created: 2018-04-02 Last updated: 2018-06-27Bibliographically approved
Asres, G. A., Baldoví, J. J., Dombovari, A., Järvinen, T., Lorite, G. S., Mohl, M., . . . Kordás, K. (2018). Ultrasensitive H2S gas sensors based on p-type WS2 hybrid materials. Nano Reseach, 11(8), 4215-4224
Open this publication in new window or tab >>Ultrasensitive H2S gas sensors based on p-type WS2 hybrid materials
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2018 (English)In: Nano Reseach, ISSN 1998-0124, E-ISSN 1998-0000, Vol. 11, no 8, p. 4215-4224Article in journal (Refereed) Published
Abstract [en]

Owing to their higher intrinsic electrical conductivity and chemical stability with respect to their oxide counterparts, nanostructured metal sulfides are expected to revive materials for resistive chemical sensor applications. Herein, we explore the gas sensing behavior of WS2 nanowire-nanoflake hybrid materials and demonstrate their excellent sensitivity (0.043 ppm-1) as well as high selectivity towards H2S relative to CO, NH3, H2, and NO (with corresponding sensitivities of 0.002, 0.0074, 0.0002, and 0.0046 ppm-1, respectively). Gas response measurements, complemented with the results of X-ray photoelectron spectroscopy analysis and first-principles calculations based on density functional theory, suggest that the intrinsic electronic properties of pristine WS2 alone are not sufficient to explain the observed high sensitivity towards H2S. A major role in this behavior is also played by O doping in the S sites of the WS2 lattice. The results of the present study open up new avenues for the use of transition metal disulfide nanomaterials as effective alternatives to metal oxides in future applications for industrial process control, security, and health and environmental safety.

Place, publisher, year, edition, pages
Springer, 2018
Keywords
WS2, nanowire, nanoflake, gas sensor, H2S, O doping
National Category
Materials Chemistry
Identifiers
urn:nbn:se:umu:diva-146528 (URN)10.1007/s12274-018-2009-9 (DOI)000440733100023 ()
Available from: 2018-04-12 Created: 2018-04-12 Last updated: 2018-09-04Bibliographically approved
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