5 research outputs found
Π‘ΠΈΠ½ΡΠ΅Π· Π²ΡΡΡΠΈΡ ΡΠΏΠΈΡΡΠΎΠ² Π½Π° LaCo- ΠΈ LaCoCu-ΠΏΠ΅ΡΠΎΠ²ΡΠΊΠΈΡΠ°Ρ , ΠΏΡΠΎΠΌΠΎΡΠΈΡΠΎΠ²Π°Π½Π½ΡΡ ΡΠ΅ΡΠ΅Π±ΡΠΎΠΌ
LaCoO3 and LaCo0.7Cu0.3O3 perovskites supported on highly dispersed mesoporous silica KITβ6 were impregnated with silver nitrate (nAg/nCo = 4/99 and 8/99). The phase composition of the initial samples and samples after catalytic tests in syngas conversion and catalytic characteristics have been investigated. The regularities of the transformation of samples in the process of reduction in a hydrogen-containing gas have been studied. It is shown that, for the LaCoO3 sample, with an increase in the silver content, the activity and selectivity for higher alcohols increase from 6 to 23 %. The maximum interaction of cobalt with silver is observed at a silver content of 4 %. At a higher content, part of the cobalt is reduced regardless of the influence of silver due to its faster agglomeration. This leads to a stronger amorphization of the reduced sample and a sharp increase in its activity. The LaCo0.7Cu0.3O3 sample exhibits a higher selectivity for higher alcohols (36 %) due to the effect of copper. Silver promotion of the sample allows achieving the maximum selectivity for higher alcohols of 56 % with a silver content of 4 %. A further increase in the silver content leads to a sharp decrease in the selectivity for higher alcohols (41 %) and the appearance of CO2 due to the saturation of copper-containing particles with silver and a decrease in the interaction of cobalt with copperΠΠ΅ΡΠΎΠ²ΡΠΊΠΈΡΡ LaCoO3 ΠΈ LaCo0.7Cu0.3O3, Π½Π°Π½Π΅ΡΠ΅Π½Π½ΡΠ΅ Π½Π° Π²ΡΡΠΎΠΊΠΎΠ΄ΠΈΡΠΏΠ΅ΡΡΠ½ΡΠΉ ΠΌΠ΅Π·ΠΎΠΏΠΎΡΠΈΡΡΡΠΉ
ΠΊΡΠ΅ΠΌΠ½Π΅Π·Π΅ΠΌ KITβ6, ΠΏΡΠΎΠΏΠΈΡΡΠ²Π°Π»ΠΈΡΡ Π½ΠΈΡΡΠ°ΡΠΎΠΌ ΡΠ΅ΡΠ΅Π±ΡΠ° (nAg/nCo = 4/99 ΠΈ 8/99). ΠΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ ΡΠ°Π·ΠΎΠ²ΡΠΉ
ΡΠΎΡΡΠ°Π² ΠΈΡΡ
ΠΎΠ΄Π½ΡΡ
ΠΎΠ±ΡΠ°Π·ΡΠΎΠ² ΠΈ ΠΎΠ±ΡΠ°Π·ΡΠΎΠ² ΠΏΠΎΡΠ»Π΅ ΠΊΠ°ΡΠ°Π»ΠΈΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΈΡΠΏΡΡΠ°Π½ΠΈΠΉ Π² ΠΊΠΎΠ½Π²Π΅ΡΡΠΈΠΈ ΡΠΈΠ½ΡΠ΅Π·-Π³Π°Π·Π°
ΠΈ ΠΊΠ°ΡΠ°Π»ΠΈΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΠΈ ΠΎΠ±ΡΠ°Π·ΡΠΎΠ². ΠΠ·ΡΡΠ΅Π½Ρ Π·Π°ΠΊΠΎΠ½ΠΎΠΌΠ΅ΡΠ½ΠΎΡΡΠΈ ΠΏΡΠ΅Π²ΡΠ°ΡΠ΅Π½ΠΈΡ ΠΎΠ±ΡΠ°Π·ΡΠΎΠ²
Π² ΠΏΡΠΎΡΠ΅ΡΡΠ΅ Π²ΠΎΡΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΈΡ Π² Π²ΠΎΠ΄ΠΎΡΠΎΠ΄ΡΠΎΠ΄Π΅ΡΠΆΠ°ΡΠ΅ΠΌ Π³Π°Π·Π΅. ΠΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΡΠΎ Π΄Π»Ρ ΠΎΠ±ΡΠ°Π·ΡΠ° LaCoO3
Ρ ΡΠΎΡΡΠΎΠΌ ΡΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΡ ΡΠ΅ΡΠ΅Π±ΡΠ° ΡΠ²Π΅Π»ΠΈΡΠΈΠ²Π°Π΅ΡΡΡ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΡ ΠΈ ΡΠ΅Π»Π΅ΠΊΡΠΈΠ²Π½ΠΎΡΡΡ ΠΏΠΎ Π²ΡΡΡΠΈΠΌ ΡΠΏΠΈΡΡΠ°ΠΌ
Ρ 6 Π΄ΠΎ 23 %. ΠΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΠ΅ Π²Π·Π°ΠΈΠΌΠΎΠ΄Π΅ΠΉΡΡΠ²ΠΈΠ΅ ΠΊΠΎΠ±Π°Π»ΡΡΠ° Ρ ΡΠ΅ΡΠ΅Π±ΡΠΎΠΌ Π½Π°Π±Π»ΡΠ΄Π°Π΅ΡΡΡ ΠΏΡΠΈ ΡΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΠΈ
4 % ΡΠ΅ΡΠ΅Π±ΡΠ°. ΠΡΠΈ Π±ΠΎΠ»ΡΡΠ΅ΠΌ ΡΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΠΈ ΡΠ°ΡΡΡ ΠΊΠΎΠ±Π°Π»ΡΡΠ° Π²ΠΎΡΡΡΠ°Π½Π°Π²Π»ΠΈΠ²Π°Π΅ΡΡΡ Π½Π΅Π·Π°Π²ΠΈΡΠΈΠΌΠΎ ΠΎΡ Π²Π»ΠΈΡΠ½ΠΈΡ
ΡΠ΅ΡΠ΅Π±ΡΠ° Π²ΡΠ»Π΅Π΄ΡΡΠ²ΠΈΠ΅ Π΅Π³ΠΎ Π±ΠΎΠ»Π΅Π΅ Π±ΡΡΡΡΠΎΠΉ Π°Π³Π»ΠΎΠΌΠ΅ΡΠ°ΡΠΈΠΈ. ΠΡΠΎ ΠΏΡΠΈΠ²ΠΎΠ΄ΠΈΡ ΠΊ Π±ΠΎΠ»Π΅Π΅ ΡΠΈΠ»ΡΠ½ΠΎΠΉ Π°ΠΌΠΎΡΡΠΈΠ·Π°ΡΠΈΠΈ
Π²ΠΎΡΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½Π½ΠΎΠ³ΠΎ ΠΎΠ±ΡΠ°Π·ΡΠ° ΠΈ ΡΠ΅Π·ΠΊΠΎΠΌΡ ΡΠΎΡΡΡ Π΅Π³ΠΎ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ. ΠΠ±ΡΠ°Π·Π΅Ρ LaCo0.7Cu0.3O3 ΠΏΡΠΎΡΠ²Π»ΡΠ΅Ρ Π±ΠΎΠ»Π΅Π΅
Π²ΡΡΠΎΠΊΡΡ ΡΠ΅Π»Π΅ΠΊΡΠΈΠ²Π½ΠΎΡΡΡ ΠΏΠΎ Π²ΡΡΡΠΈΠΌ ΡΠΏΠΈΡΡΠ°ΠΌ (36 %) Π±Π»Π°Π³ΠΎΠ΄Π°ΡΡ Π²Π»ΠΈΡΠ½ΠΈΡ ΠΌΠ΅Π΄ΠΈ. ΠΡΠΎΠΌΠΎΡΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅
ΠΎΠ±ΡΠ°Π·ΡΠ° ΡΠ΅ΡΠ΅Π±ΡΠΎΠΌ ΠΏΠΎΠ·Π²ΠΎΠ»ΡΠ΅Ρ Π΄ΠΎΡΡΠΈΡΡ ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΠΉ ΡΠ΅Π»Π΅ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ ΠΏΠΎ Π²ΡΡΡΠΈΠΌ ΡΠΏΠΈΡΡΠ°ΠΌ Π² 56 %
ΠΏΡΠΈ ΡΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΠΈ ΡΠ΅ΡΠ΅Π±ΡΠ° Π² 4 %. ΠΠ°Π»ΡΠ½Π΅ΠΉΡΠ΅Π΅ ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΠ΅ ΡΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΡ ΡΠ΅ΡΠ΅Π±ΡΠ° ΠΏΡΠΈΠ²ΠΎΠ΄ΠΈΡ ΠΊ ΡΠ΅Π·ΠΊΠΎΠΌΡ
ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΡ ΡΠ΅Π»Π΅ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ ΠΏΠΎ Π²ΡΡΡΠΈΠΌ ΡΠΏΠΈΡΡΠ°ΠΌ (41 %) ΠΈ ΠΏΠΎΡΠ²Π»Π΅Π½ΠΈΡ CO2 Π²ΡΠ»Π΅Π΄ΡΡΠ²ΠΈΠ΅ Π½Π°ΡΡΡΠ΅Π½ΠΈΡ
ΠΌΠ΅Π΄ΡΡΠΎΠ΄Π΅ΡΠΆΠ°ΡΠΈΡ
ΡΠ°ΡΡΠΈΡ ΡΠ΅ΡΠ΅Π±ΡΠΎΠΌ ΠΈ ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΡ Π²Π·Π°ΠΈΠΌΠΎΠ΄Π΅ΠΉΡΡΠ²ΠΈΡ ΠΊΠΎΠ±Π°Π»ΡΡΠ° Ρ ΠΌΠ΅Π΄Ρ
Synthesis of LaCoOβin Mild Hydrothermal Conditions
Π Π°ΡΡΠΌΠΎΡΡΠ΅Π½Ρ Π·Π°ΠΊΠΎΠ½ΠΎΠΌΠ΅ΡΠ½ΠΎΡΡΠΈ ΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΎΠΊΡΠΈΠ΄Π° LaCoO3 ΡΠΎ ΡΡΡΡΠΊΡΡΡΠΎΠΉ ΡΠΈΠΏΠ° ΠΏΠ΅ΡΠΎΠ²ΡΠΊΠΈΡΠ°
ΠΈΠ· ΠΏΡΠ΅Π΄ΡΠ΅ΡΡΠ²Π΅Π½Π½ΠΈΠΊΠΎΠ², ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΡ
ΡΠΈΡΡΠ°ΡΠ½ΡΠΌ ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ ΠΈ ΠΏΠΎ ΠΎΡΠΈΠ³ΠΈΠ½Π°Π»ΡΠ½ΠΎΠΉ ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠ΅
ΠΎΡΠ°ΠΆΠ΄Π΅Π½ΠΈΡ Π² ΡΡΠ»ΠΎΠ²ΠΈΡΡ
ΠΌΡΠ³ΠΊΠΎΠ³ΠΎ Π³ΠΈΠ΄ΡΠΎΡΠ΅ΡΠΌΠ°Π»ΡΠ½ΠΎΠ³ΠΎ ΡΠΈΠ½ΡΠ΅Π·Π° Ρ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ ΠΎΡΠ³Π°Π½ΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠ΅ΠΌΠΏΠ»Π°ΡΠΎΠ²: ΡΡΠΈΠ»Π΅Π½Π³Π»ΠΈΠΊΠΎΠ»Ρ, D-Π³Π»ΡΠΊΠΎΠ·Ρ, D-Π³Π°Π»Π°ΠΊΡΠΎΠ·Ρ ΠΈ D-ΡΡΡΠΊΡΠΎΠ·Ρ. ΠΡΠ΅Π΄Π»ΠΎΠΆΠ΅Π½Π½Π°Ρ ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠ°
ΡΠΈΠ½ΡΠ΅Π·Π° ΠΎΠ±Π΅ΡΠΏΠ΅ΡΠΈΠ²Π°Π΅Ρ Π½Π΅ΠΎΠ±Ρ
ΠΎΠ΄ΠΈΠΌΡΡ Π³ΠΎΠΌΠΎΠ³Π΅Π½ΠΈΠ·Π°ΡΠΈΡ ΠΊΠ°ΡΠΈΠΎΠ½ΠΎΠ² Π² ΠΏΠΎΠ»ΡΡΠ°Π΅ΠΌΠΎΠΌ ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΠΈ
ΠΏΡΠ΅Π΄ΡΠ΅ΡΡΠ²Π΅Π½Π½ΠΈΠΊΠ΅ ΠΈ Π³ΠΎΠΌΠΎΡΠ°Π·Π½ΠΎΡΡΡ ΠΎΠΊΡΠΈΠ΄Π½ΠΎΠ³ΠΎ ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΡRegularities of formation of LaCoO3 oxide with a perovskite-type structure from precursors obtained
by the citrate method and the original deposition method under conditions of mild hydrothermal
synthesis using organic templates: ethylene glycol, D-glucose, D-galactose and D-fructose are
considered. The proposed method of synthesis provides the necessary homogenization of cations in
the resulting precursor compound and the homogeneous nature of the oxide compound. The absence
at the final stage of the synthesis of reducing conditions makes it possible to further modify the formed
perovskite with noble metal
Interaction of hydrogen with Cu-Zn mixed oxide model methanol synthesis catalyst
ENERGIE:MATERIAUX+HJOInteraction of hydrogen with model Cu-Zn methanol synthesis catalyst prepared by decomposition of mixed hydroxicarbonate is studied by inelastic neutron scattering, in situ FTIR/MS, and thermal analysis. Reduced (Cu-0.08,Zn-0.92)O mixed oxide accumulates 6H/Cu, mainly as hydride, hydroxyl and formate species. The reduction of copper in the (Cu,Zn)O mixed oxide occurs via a reversible redox interaction with H-2 and absorption of protons as OH--groups with nu =3250 cm(-1) and delta approximate to 1430-1480 cm(-1). Kinetic and thermodynamic parameters of this process are evaluated. The weight loss during the reduction is due to the decomposition of the residual carbonate groups to CO2 via formate intermediates, which occurs in the presence of hydrogen. Exposure of (Cu,Zn)O to air prior to the reduction strongly affects the kinetic parameters of the reduction process. (C) 2013 Elsevier B.V. All rights reserved