Papers by Valentin Parmon
HAL (Le Centre pour la Communication Scientifique Directe), Jun 28, 2012
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Catalysts
A series of tin oxides were synthesized with polystyrene microspheres (250 nm) as the template. I... more A series of tin oxides were synthesized with polystyrene microspheres (250 nm) as the template. It was shown that an increase in the template content led to increasing specific pore volume and to the formation of bimodal pore structure with pores of 9 and 70 nm in diameter. Addition of cetyltrimethylammonium bromide (CTAB) during synthesis led to the formation of friable structures (SEM data), to an increase in the average pore diameter from 19 to 111 nm, and to the formation of macropores of 80–400 nm in size. All materials had similar surface properties and cassiterite structure with 5.9–10.8 nm coherent scattering region (XRD data). Flat-band potentials of the samples were determined and their photoelectrocatalytic properties to oxidation of water and methanol were studied in the potential range of 0.4–1.6 V RHE. It was shown that the sample obtained using CTAB was characterized by lower flat-band potential value, but appeared significantly higher photocurrent in methanol oxidati...
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Альтернативная энергетика и экология, 2011
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The authors conducted a systematic study of carbon material series «Sibunit» (S4) prospective for... more The authors conducted a systematic study of carbon material series «Sibunit» (S4) prospective for the processes of oxidative treatment of industrial waste. The effect of the conditions of oxidative treatmentof «Sibunit» (S4) on the chemical composition of its surface and catalytic properties in the deep oxidation of organic toxicants in aqueous solutions was investigated. The influence of the chemical composition of the surface of oxidized under different conditions of the carbon material S4 on its catalytic properties in the liquid-phase aerobic oxidation of phenol, and the catalytic properties of ruthenium catalysts (3 wt.% Ru), prepared on samples of oxidized carbon support S4. Active carbon samples in the oxidation of phenol was detected and it increases with the number of carbonyl and phenolic groups on the carbon surface and decreases with the number of carboxyl and lactone groups. However, the activity of carbon samples noticeably inferior Ru-containing catalysts. The optimal...
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Catalysts, 2021
The one-pot hydrolysis-dehydration of activated microcrystalline cellulose was studied in pure hy... more The one-pot hydrolysis-dehydration of activated microcrystalline cellulose was studied in pure hydrothermal water at 453 K over ZrO2 catalysts produced by thermodegradation, microwave treatment, mechanical activation, and sol–gel methods and spent without any co-catalyst. ZrO2 prepared by microwave treatment was more active compared to ones derived by other methods. The catalyst calcination temperature also impacted reactivity. The cellulose conversion increased simultaneously with acidity and SBET, which in turn were set by the preparation method and calcination temperature. Phase composition did not affect the activity. Yields of glucose and 5-HMF reaching 18 and 15%, respectively, were over the most promising ZrO2 prepared by microwave treatment at 593 K. To our knowledge, this ZrO2 sample provided the highest activity in terms of TOF values (15.1 mmol g−1 h−1) compared to the pure ZrO2 systems reported elsewhere. High stability of ZrO2 derived by microwave irradiation was shown ...
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RSC Advances, 2020
Influence of composition of catalysts based on heteropoly acid cesium salts on formic acid produc... more Influence of composition of catalysts based on heteropoly acid cesium salts on formic acid production via starch hydrolysis–oxidation was investigated.
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BMC Microbiology, 2020
Background The Uzon Caldera is one of the places on our planet with unique geological, ecological... more Background The Uzon Caldera is one of the places on our planet with unique geological, ecological, and microbiological characteristics. Uzon oil is the youngest on Earth. Uzon oil has unique composition, with low proportion of heavy fractions and relatively high content of saturated hydrocarbons. Microbial communities of the «oil site» have a diverse composition and live at high temperatures (up to 97 °C), significant oscillations of Eh and pH, and high content of sulfur, sulfides, arsenic, antimony, and mercury in water and rocks. Results The study analyzed the composition, structure and unique genetics characteristics of the microbial communities of the oil site, analyzed the metabolic pathways in the communities. Metabolic pathways of hydrocarbon degradation by microorganisms have been found. The study found statistically significant relationships between geochemical parameters, taxonomic composition and the completeness of metabolic pathways. It was demonstrated that geochemical...
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Journal of Siberian Federal University. Chemistry, 2020
The impact of the preparation techniques of niobium oxide and two-component systems based on niob... more The impact of the preparation techniques of niobium oxide and two-component systems based on niobium and zirconium oxides on the catalytic properties was studied in the one-pot hydrolysisdehydration of cellulose into glucose and 5-hydroxymethylfurfural. Cellulose transformation was performed in an autoclave at 180 °С under argon atmosphere. The most promising methods for the preparation of solid catalysts were found to be microwave heating and mechanical activation. Glucose and 5-hydroxymethylfurfural can be produced with total yield equal to 20-21 % in the presence of catalysts prepared using these techniques
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Energies, 2019
Formic acid is a promising liquid organic hydrogen carrier (LOHC) since it has relatively high hy... more Formic acid is a promising liquid organic hydrogen carrier (LOHC) since it has relatively high hydrogen content (4.4 wt%), low inflammability, low toxicity and can be obtained from biomass or from CO2. The aim of the present research was the creation of efficient 1 wt% Pd catalysts supported on mesoporous graphitic carbon (Sibunit) for the hydrogen production from gas-phase formic acid. For this purpose, the carbon support was modified by pyrolysis of deposited precursors containing pyridinic nitrogen such as melamine (Mel), 2,2′-bipyridine (Bpy) or 1,10-phenanthroline (Phen) at 673 K. The following activity trend of the catalysts Pd/Mel/C > Pd/C ~ Pd/Bpy/C > Pd/Phen/C was obtained. The activity of the Pd/Mel/C catalyst was by a factor of 4 higher than the activity of the Pd/C catalyst at about 373 K and the apparent activation energy was significantly lower than those for the other catalysts (32 vs. 42–46 kJ/mol). The high activity of the melamine-based samples was explained ...
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Доклады Академии наук, 2019
The promise of СuO-CeO2/γ-Al2O3 catalysts for partial oxidation of dimethyl ether (DME) to hydrog... more The promise of СuO-CeO2/γ-Al2O3 catalysts for partial oxidation of dimethyl ether (DME) to hydrogen-rich gas for fuel cell feeding was demonstrated. The catalysts provided complete conversion of DME to hydrogen-rich gas with low (≤ 0,8 vol.%) CH4 content and Н2 productivity ~3,1 l/(gcat · h) at 350 °C under ambient pressure using a reaction mixture (molar ratio): DME : O2 : N2 = 1 : 1 : 4 (DME : air = 1 : 5) at a flow rate 7 l/(gcat · h).
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Doklady Physical Chemistry, 2019
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Доклады Академии наук, 2019
Coking of anthracene at 400–600°C in the presence or in the absence of a cobalt catalyst supporte... more Coking of anthracene at 400–600°C in the presence or in the absence of a cobalt catalyst supported on carbon nanotubes (CNTs) was studied for the first time. The coking products were examined by X-ray diffraction and electron microscopy. The CoO-CNTs catalyst considerably (by 50°C) decreased the temperature of the onset of coking and accelerated the coke formation. The presence of CoO-CNTs changed the coke morphology. Whereas coking of pure anthracene affords ~1 micron spherical particles of poorly crystallized carbon, in the presence of the catalyst, a carbon “coating” covering the CNT surface is formed.
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Topics in Catalysis, 2019
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High Energy Chemistry, 2018
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Electrochimica Acta, 2018
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Journal of Siberian Federal University. Chemistry, 2016
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Journal of Siberian Federal University. Chemistry, 2016
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Gas Turbines, 2010
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Materials Research Innovations, 2001
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Papers by Valentin Parmon