共查询到20条相似文献,搜索用时 31 毫秒
1.
G. B. Narochnyi R. E. Yakovenko A. P. Savost’yanov V. G. Bakun 《Catalysis in Industry》2016,8(2):139-144
The experience in introducing the technology of for the production of a silica-supported cobalt catalyst under industrial conditions is summarized. The catalyst is designed for the selective synthesis of С5+ hydrocarbons from СО and Н2, including macromolecular hydrocarbons С35+. The technology has been implemented at ZAO Samara Catalyst Factory. Parameters of the technological process are adjusted to allow for the features of existing equipment in preparing an experimental industrial lot of catalysts. The optimum technological mode of support preparation (evacuation to avoid granule cracking), its impregnation (at 80°С over 30 min), and the thermal treatment of the catalyst (in programmed mode at a maximum temperature of 400°С over a total of 9 h) are determined. The catalysts of an experimental industrial lot of 1 m3 conform to the new technical conditions in their physicochemical and catalytic properties. 相似文献
2.
P. P. Minaev A. S. Koklyukhin K. I. Maslakov P. A. Nikulshin 《Catalysis in Industry》2017,9(2):146-155
Со(Ni)–PMo(W)/Al2O3 catalysts are prepared using Keggin heteropoly acids H3PMo(W)12O40 and cobalt (nickel) citrate. The physicochemical properties of the catalysts are studied via low-temperature nitrogen adsorption, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. Their catalytic properties are determined in the hydrotreatment of a model raw material containing dibenzothiophene, naphthalene, and different amounts of quinoline (up to 1000 ppm of nitrogen), and in the hydrotreatment of a straight-run diesel fraction and vacuum gas oil. The composition of Со(Ni)–PMo(W)/Al2O3 catalysts plays an important role in the hydrotreatment of a complex hydrocarbon raw material. Ni–PW/Al2O3 catalyst is more resistant to organonitrogen inhibitors than Ni(Co)–PMo/Al2O3 samples with more reactive active sites. Ni–PW/Al2O3 catalyst provides the greatest depth of conversion for sulfur- and nitrogen-containing compounds and polycyclic aromatic hydrocarbons in the hydrotreatment of vacuum gas oil. 相似文献
3.
Ameer Abed Jaddoa T. R. Bilalov F. M. Gumerov F. R. Gabitov Z. I. Zaripov R. S. Yarullin A. A. Pimerzin P. A. Nikul’shin 《Catalysis in Industry》2017,9(1):31-38
Results from studying the supercritical fluid СО2-extraction regeneration of DN-3531 industrial nickel–molybdenum hydrotreatment catalyst in the temperature range of 323.15–383.15 K, at pressures of up to 30 MPa, and with modification of the basic extragent with such polar compounds as chloroform, methanol, ethanol, acetone, and dimethylsulfoxide (DMSO), are presented. The order of modifiers corresponds to the increase in the solubilizing ability of modified supercritical carbon dioxide (SC-СО2) with respect to catalyst- deactivating deposits. With DMSO as the most efficient modifier, however, not only are deactivating compounds removed but nickel and molybdenum as well, considerably reducing the final activity of a regenerated sample. During extraction regeneration, the content of coke in the catalyst is reduced by two-thirds, while the specific surface area and the pore volume grow. The activity of the deactivated catalyst in dibenzothiophene hydrodesulfurization (HDS) and naphthalene hydrogenation grows by several hundred per cent after one-time SC-CO2 treatment and is 2.5 times higher than for a sample regenerated using the traditional oxidative method. 相似文献
4.
Bi3Mo2Fe1P x oxide catalysts were prepared by a co-precipitation method and the influence of phosphorous content on the catalytic performance in the oxidative dehydrogenation of 1-butene was investigated. The addition of phosphorous up to 0.4mole ratio to Bi3Mo2Fe1 oxide catalyst led to an increase in the catalytic performance; however, a higher phosphorous content (above P=0.4) led to a decrease of conversion. Of the tested catalysts, Bi3Mo2Fe1P0.4 oxide catalyst exhibited the highest catalytic performance. Characterization results showed that the catalytic performance was related to the quantity of a π-allylic intermediate, facile desorption behavior of adsorbed intermediates and ability for re-oxidation of catalysts. 相似文献
5.
Using the well-known patent methods, we have synthesized 1,3-butadiene epoxidation α-Al2O3 supported catalysts containing 15 wt % of Ag and 250–1500 ppm of Cs (Johnson Matthey, H16P07). The physicochemical properties of samples are systematically studied by varying the dispersion of supported silver, the amount of an introduced promoter, and its distribution over the surface of a catalyst. Catalytic tests of samples show that the optimum amount of a promoter depends directly on the surface of a catalyst. With optimum promotion, the steady-state activity of catalysts is determined by the dispersion of supported silver. In the course of catalytic tests, it is established that the shape of kinetic curves is governed by the excess or lack of Cs in a catalyst, thus providing a method for optimizing the concentration of the promoter. An analysis of the energy dispersion spectra (EDS) is applied for the first time to study the distribution of Cs over the surface of promoted catalysts. It is shown that thermal treatment favors the uniform distribution of a promoter over the surface of a catalyst and shortens the time required to attain its steady-state activity in catalytic tests. In our work, the steady-state productivity of catalysts reaches 0.5 g of 3,4-epoxy-1-butene per gram of the catalyst per hour, thus exceeding the claimed patent values. 相似文献
6.
S. A. Kurta 《Catalysis in Industry》2011,3(2):136-143
Selecting the best catalyst for large-scale industrial processes of the oxychlorination of ethylene (OCE) is a practical task
of great importance. In such processes, even a slight reduction in selectivity results in considerable losses of raw materials.
The enhancement of selectivity requires knowledge of the structure of the catalysts’ surfaces and the mechanism of the process
of oxidative chlorination of ethylene into 1,2-dichloroethane (1,2-DCE). The structure of active sites of copper chloride
catalysts on the surface of alumina was studied by physicochemical methods of IR spectroscopy and DTA. The structure was described
for the active sites of catalysts for the oxidative chlorination of ethylene into (1,2-DCE) of two types, CuCl2 and CuCl on γ-Al2O3: H1 (Harshow, United States) and OXYMAX-B (MEDC-B) (Sǜd-Chemie Catalysts, Germany). It was ascertained that complex compounds
with [CuCl4]−2 and [CuCl2]−1 are formed upon interaction between the active phase of the catalyst (copper chlorides CuCl2 or CuCl), and the surface groups of the support γ-Al2O3 (≡Al-OH) (this observation does not fall into the known theory of their structure). In accordance with the results from our
study, a method was elaborated for synthesizing a catalyst with the optimum properties for OCE, and a pilot setup for the
detailed investigation of this process was built. The possibility of cutting ethylene losses in half during deep oxidation
and eliminating the formation of side products by a factor of 1.5–2 was demonstrated by the industrial production of 1,2-DCE
and vinyl chloride at OOO Karpatnaftokhim in Kalush. The method for producing 1,2-DCE is protected by a Ukranian patent. 相似文献
7.
S. O. Soloviev 《Catalysis in Industry》2012,4(1):1-10
The catalytic properties of Ni/Al2O3 composites supported on ceramic cordierite honeycomb monoliths in oxidative methane reforming are reported. The prereduced
catalyst has been tested in a flow reactor using reaction mixtures of the following compositions: in methane oxidation, 2–6%
CH4, 2–9% O2, Ar; in carbon dioxide and oxidative carbon dioxide reforming of methane, 2–6% CH4, 6–12% CO2, and 0–4% O2, and Ar. Physicochemical studies include the monitoring of the formation and oxidation of carbon, the strength of the Ni-O
bond, and the phase composition of the catalyst. The structured Ni-Al2O3 catalysts are much more productive in the carbon dioxide reforming of methane than conventional granular catalysts. The catalysts
performance is made more stable by regulating the acid-base properties of their surface via the introduction of alkali metal
(Na, K) oxides to retard the coking of the surface. Rare-earth metal oxides with a low redox potential (La2O3, CeO2) enhance the activity and stability of Ni-Al2O3/cordierite catalysts in the deep and partial oxidation and carbon dioxide reforming of methane. The carbon dioxide reforming
of methane on the (NiO + La2O3 + Al2O3)/cordierite catalyst can be intensified by adding oxygen to the gas feed. This reduces the temperature necessary to reach
a high methane conversion and does not exert any significant effect on the selectivity with respect to H2. 相似文献
8.
G. A. Bukhtiyarova E. N. Vlasova P. V. Aleksandrov A. V. Toktarev Yu. V. Patrushev A. S. Noskov D. O. Kondrashev V. A. Golovachev A. V. Kleymenov P. A. Abrashenkov S. E. Kuznetsov V. V. Galkin 《Catalysis in Industry》2017,9(3):212-220
It is proposed that the sulfide NiMo system supported on alumina-SAPO-31 composite (NiMo/Al2O3-SAP catalyst) be used to obtain high-quality diesel fuel from a mixture of straight run diesel (SRGO) and light cycle oil (LCO) produced by fluid catalytic cracking (FCC). It is shown that the use of this catalyst ensures the synthesis of diesel fuel of higher quality upon hydroprocessing a feedstock with 30 wt % LCO, compared to the traditional sulfide NiMo/Al2O3 or CoMo/Al2O3 catalysts. It is found that the content of aliphatic hydrocarbons is raised in the products of hydrotreatment, compared to the initial feedstock. This confirms the ability of NiMo/Al2O3-SAP catalyst to facilitate the reaction of ring opening. Using the proposed catalyst should improve the quality of diesel fuels obtained via the hydroprocessing of LCO-containing feedstock. 相似文献
9.
Sun Ho Song Sang Hee Lee Dong Ryul Park Heesoo Kim Sung Yul Woo Won Seob Song Myong Suk Kwon In Kyu Song 《Korean Journal of Chemical Engineering》2009,26(6):1539-1544
Methods for regenerating H3PW12O40 catalyst in the solvent-free direct preparation of dichloropropanol (DCP) from glycerol and hydrochloric acid gas were investigated.
Regenerated H3PW12O40 catalyst was then applied to the solvent-free direct preparation of DCP. In the solvent-free direct preparation of DCP, selectivity
for DCP over H3PW12O40 catalyst regenerated by method I (recovery of solid H3PW12O40 catalyst by evaporating homogeneous liquidphase product solution) significantly decreased with increasing recycling run,
while that over H3PW12O40 catalyst regenerated by method II (regeneration of H3PW12O40 catalyst by oxidative calcination of solid product recovered by method I) was slightly decreased with no significant catalyst
deactivation with respect to recycling run. On the other hand, selectivity for DCP over H3PW12O40 catalyst regenerated by method III (regeneration of H3PW12O40 catalyst by recrystallization and subsequent oxidative calcination of solid product recovered by method II) was the same
as that over fresh catalyst without any catalyst deactivation with respect to recycling run. Thus, method III was found to
be the most efficient method for the regeneration of H3PW12O40 catalyst. 相似文献
10.
Chuanmin Chen Wenbo Jia Songtao Liu Yue Cao Bing Zhao Jianqiao Wang 《Korean Journal of Chemical Engineering》2018,35(3):637-644
CuCl2-SCR catalysts prepared by an improved impregnation method were studied to evaluate the catalytic performance for gaseous elemental mercury (Hg0) oxidation in simulated flue gas. Hg0 oxidation activity of commercial SCR catalyst was significantly improved by the introduction of CuCl2. Nitrogen adsorption, XRD, XRF and XPS were used to characterize the catalysts. The results indicated that CuCl2 was well loaded and highly dispersed on the catalyst surface, and that CuCl2 played an important role for Hg0 catalytic oxidation. The effects of individual flue gas components on Hg0 oxidation were also investigated over CuCl2-SCR catalyst at 350 oC. The co-presence of NO and NH3 remarkably inhibited Hg0 oxidation, while this inhibiting effect was gradually scavenged with the decrease of GHSV. Further study revealed the possibility of simultaneous removal of Hg0 and NO over CuCl2-SCR catalyst in simulated flue gas. The mechanism of Hg0 oxidation was also investigated. 相似文献
11.
Oxidative dehydrogenation of n-butene to 1,3-butadiene over sulfated ZnFe2O4 catalyst was carried out in a continuous flow fixed-bed reactor. The effect of sulfation on the catalytic performance of ZnFe2O4 was investigated. Sulfated ZnFe2O4 catalyst showed a better catalytic performance than ZnFe2O4 catalyst in the oxidative dehydrogenation of n-butene. Acid–base property of sulfated ZnFe2O4 catalyst was measured by TPD experiment, with an aim of correlating the catalytic performance with the surface acid–base property of the catalyst. It was revealed that the catalytic performance of sulfated ZnFe2O4 catalyst was closely related to the surface weak-acid density of the catalyst. The enhanced acidity of sulfated ZnFe2O4 catalyst was responsible for its high catalytic performance in the oxidative dehydrogenation of n-butene. Thus, sulfation served as an efficient method for improving catalytic performance of ZnFe2O4 in the oxidative dehydrogenation of n-butene. 相似文献
12.
C. Sepulveda R. Garcia N. Escalona D. Laurenti L. Massin M. Vrinat 《Catalysis Letters》2011,141(7):987-995
Abstract
Rhenium sulfide based catalysts were prepared by the incipient wetness impregnation method over alumina and silica supports and evaluated for 4,6-dimethyldibenzothiophene hydrodesulfurization in a high-pressure stirred-tank reactor. The catalyst prepared over silica was about six times more active for hydrodesulfurization than the corresponding catalyst prepared over alumina and a NiMo/Al2O3 industrial reference catalyst. This surprising and positive SiO2 support effect was explained by a metallic character of the supported sulfide, which was demonstrated using a kinetic approach of competitive hydrogenations and by XPS characterization. 相似文献13.
P. P. Dik V. Yu. Pereima K. A. Nadeina M. O. Kazakov O. V. Klimov E. Yu. Gerasimov I. P. Prosvirin A. S. Noskov 《Catalysis in Industry》2018,10(1):20-28
The effect of the W: (W + Mo) atomic ratio in NiMoW trimetallic catalysts on their catalytic and physicochemical properties is studied. The catalysts are prepared by impregnating a carrier containing amorphous aluminosilicate (AAS) and aluminium oxide with an aqueous solution containing Ni, Mo, W compounds, and citric acid. They are studied via XRF, TEM, NH3 TPD, and low-temperature nitrogen adsorption and are tested in the hydrocracking of vacuum gasoil (VGO). The average length of a sulfide active component layer shrinks as the amount of Mo increases and the amount of W in the catalyst is reduced. XPS data indicate that the degree of sulfidation of tungsten in NiMoW trimetallic catalysts is lower than in NiW catalyst. Testing of the catalysts in hydrocracking of a straight-line VGO at 390–420°C, 16 MPa, a feedstock hourly space velocity (FHSV) of 0.71 h?1, and a H2: VGO ratio of 1200 L/L shows the activities of hydrodesulfurization, hydrodenitrogenation, hydrogenation, and hydrocracking grow along with the W: (W + Mo) ratio. When the process pressure is high and the amount of sulfur in the NiW feedstock is low, the catalysts have higher activity in the target reactions of VGO hydrocracking than NiMo catalyst. 相似文献
14.
Nickel doped manganese oxide supported on titania materials were investigated for the low-temperature NH3-SCR. For this purpose, a series of Ni modified Mn/TiO2 catalysts were prepared and evaluated for the low-temperature SCR of NO with ammonia in the presence of excess oxygen. The
catalytic performance of these materials was compared with respect to the nickel weight percentage in order to examine the
correlation between physicochemical characteristics and reactivity of optimized materials. It was found that the 5% Mn–2%
Ni/TiO2 catalyst showed the highest activity and yielded 100% NO conversion at 200 °C. XRD results reveal highly dispersed manganese–nickel
species on TiO2 support for the Mn–Ni/TiO2 catalysts. Our TPR data results suggested an increase in reducibility of manganese species in Mn–Ni/TiO2 catalysts. The absence of the high-temperature (736 K) peak indicates that the dominant phase is MnO2. This increase of reducibility and dominant MnO2 phase seems to be the reason for the enhanced activity and time on stream patterns of nickel-promoted titania-supported manganese
catalysts. BET results illustrate that the high NO conversion is strongly dependant on the specific surface area and pore
volume of this catalyst. All the physicochemical techniques we used suggested that the composition of manganese and nickel
oxides on the support surface is playing an important role for the enhancement of NO conversion and the prominent time on
stream stability. 相似文献
15.
Zhou-wen Fang Di Wen Zhi-hao Wang Xiang-li Long 《Korean Journal of Chemical Engineering》2018,35(11):2172-2184
The production of isophthalic acid (IPA) from the oxidation of m-xylene (MX) by air is catalyzed by H3PW12O40 (HPW) loaded on carbon and cobalt. We used H2O2 solution to oxidize the carbon to improve the catalytic activity of HPW@C catalyst. Experiments reveal that the best carbon sample is obtained by calcining the carbon at 700 °C for 4 h after being impregnated in the 3.75% H2O2 solution at 40 °C for 7 h. The surface characterization displays that the H2O2 modification leads to an increase in the acidic groups and a reduction in the basic groups on the carbon surface. The catalytic capability of the HPW@C catalyst depends on its surface chemical characteristics and physical property. The acidic groups play a more important part than the physical property. The MX conversion after 180 min reaction acquired by the HPW@C catalysts prepared from the activated carbon modified in the best condition is 3.81% over that obtained by the HPW@C catalysts prepared from the original carbon. The IPA produced by the former is 46.2% over that produced by the latter. 相似文献
16.
Ni/SiC and Ni/SiO2 catalysts prepared by both wet impregnation (WI) and deposition–precipitation (DP) methods were compared for CO and CO2 methanation. The prepared catalysts were characterized using N2 physisorption, temperature-programmed reduction with H2 (H2-TPR), H2 chemisorption, pulsed CO2 chemisorption, temperature-programmed desorption of CO2 (CO2-TPD), transmission electron microscopy, and X-ray diffraction. H2-TPR analysis revealed that the catalysts prepared by DP exhibit stronger interaction between the nickel oxides and support than those prepared by WI. The former catalysts exhibit higher Ni dispersions than the latter. The catalytic activities for both reactions over Ni/SiC and Ni/SiO2 catalysts prepared by WI increase on increasing the Ni content from 10 to 20 wt%. The Ni/SiC catalyst prepared by DP shows higher catalytic activity for CO and CO2 methanation than that of the Ni/SiC catalyst prepared by WI. Furthermore, it exhibits the highest catalytic activity for CO methanation among the tested catalysts. The high Ni dispersion achieved by the DP method and the high thermal conductivity enabled by SiC are beneficial for both CO and CO2 methanation. 相似文献
17.
A series of phosphotungstic acid (HPW)/SiO2 materials with hierarchical meso/macroporous structure were synthesized by evaporation-induced self-assembly method (EISA), using nonionic surfactant (P123) and polystyrene (PS) spheres as templates. SEM images displayed uniform macropores with an average pore size of 210 nm. TEM, small-angle XRD and N2 adsorption–desorption isotherms confirmed the existence of the ordered mesoporous structures, embedded in the wall of macropores. The wild-angle XRD and FT-IR spectra proved Keggin-type HPW dispersed homogeneously in the silica framework. With the amount of added PS spheres, the density of the macropores increased, the hierarchically ordered porous HPW/SiO2 possessed two-dimensional (2D) hexagonal (p6mm) mesostructures and uniform periodic macropores. The ODS catalytic activity of these samples were tested, the result showed that the meso/macroporous HPW/SiO2 catalyst with proper PS beads usage displayed much higher catalytic activity than other catalysts. In addition, the reusability of the meso/macroporous HPW/SiO2 catalyst was investigated, the activity of catalyst has not obviously decreased even after eight times. 相似文献
18.
Hongmei Xie Qinxiang Du Hui Li Guilin Zhou Shengming Chen Zhaojie Jiao Jianmin Ren 《Korean Journal of Chemical Engineering》2017,34(7):1944-1951
Ce1?x Cu x O2 oxide solid solution catalysts with different Ce/Cu mole ratios were synthesized by the one-pot complex method. The prepared Ce1?x Cu x O2 catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and H2 temperature-programmed reduction (H2-TPR). Their catalytic properties were also investigated by catalytic combustion of phenyl volatile organic compounds (PVOCs: benzene, toluene, xylene, and ethylbenzene) in air. XRD analysis confirmed that the CuO species can fully dissolve into the CeO2 lattice to form CeCu oxide solid solutions. XPS and H2-TPR results indicated that the prepared Ce1?x Cu x O2 catalysts contain abundant reactive oxygen species and superior reducibility. Furthermore, the physicochemical properties of the prepared Ce1?x Cu x O2 catalysts are affected by the Ce/Cu mole ratio. The CeCu3 catalyst with Ce/Cu mole ratio of 3.0 contains abundant reactive oxygen species and exhibits superior catalytic combustion activity of PVOCs. Moreover, the ignitability of PVOCs is also affected by the respective physicochemical properties. The catalytic combustion conversions of ethylbenzene, xylene, toluene, and benzene are 99%, 98.9%, 94.3%, and 62.8% at 205, 220, 225, and 225 °C, respectively. 相似文献
19.
Part III of this work continues the study of the catalytic properties of new molybdenum carbide based hydroisomerization catalysts, which are resistant to sulfur compounds and allow the synthesis of waxy diesel fuels with the same quality characteristics as those of platinum-containing catalysts. The catalytic properties of such bifunctional catalysts as 7%Mo2C/SAPO-31 (LCCH-2) and 7%Mo2C/SAPO-11 (LCCH-2-2) in diesel fraction hydroisomerization in the temperature range of 320–400°C are compared. It is shown that LCCH-2 ensures a higher yield of the hydroisomerized diesel fraction with a lower freezing point as compared to LCCH-2-2 at temperatures above 320°C. The ratio between mono- and di-isomers in reaction products is analyzed. It is concluded that SAPO-31 based catalyst is more selective to the formation of terminal monosubstituted alkanes than SAPO-11 based catalyst. The resistance of both catalysts to deactivation with coke deposits (tests over 100 h at 320 and 360°C in hydroisomerization) is studied. It is established that LCCH-2-2 is less resistant to deactivation than LCCH-2. These findings are due to differences in acidity, the degree of uniformity in the distribution of acidic hydrogenating/dehydrogenating sites in the catalysts, and the structural type of their acidic supports. 相似文献
20.
Elena A. Baranova Tariq Amir Patrick H. J. Mercier Bussaraporn Patarachao Dashan Wang Yvon Le Page 《Journal of Applied Electrochemistry》2010,40(10):1767-1777
Disordered alloy and bi-phase PtSn nanoparticles of nominal Pt:Sn ratio of 70:30 atomic % with controlled size and narrow
size distribution were synthesized using a single-step polyol method. By adjusting the solution pH it was possible to obtain
Pt7Sn3 nanoparticles of various sizes from 2.8 to 6.5 nm. We found that the presence of NaOH in the synthesis solution not only
influenced the nanoparticle size, but as it was revealed by XRD, it apparently also dictated the degree of Pt and Sn alloying.
Three catalysts prepared at lower NaOH concentrations (CNaOH < 0.15 M) showed disordered alloy structure of the nominal composition, while the other three catalysts synthesized at higher
NaOH concentrations (CNaOH > 0.15 M) consisted of bi-phase nanoparticles comprising a crystalline phase close to that of pure Pt together with an amorphous
Sn phase. These observations are plausibly due to the phase separation and formation of monometallic Pt and amorphous SnOx phases. A proposed reaction mechanism of Pt7Sn3 nanoparticle formation is presented to explain these observations along with the catalytic activities measured for the six
synthesized carbon-supported Pt7Sn3 catalysts. The highest catalytic activity towards ethanol electro-oxidation was found for the carbon-supported bi-phase catalyst
that formed the largest Pt (6.5 nm) nanoparticles and SnOx phase. The second best catalyst was a disordered alloy Pt7Sn3 catalyst with the second largest nanoparticle size (5 nm), while catalysts of smaller size (4.5–4.6 nm) but different structure
(disordered alloy vs. bi-phase) showed similar catalytic performance inferior to that of the 5 nm disordered alloy Pt7Sn3 catalyst. This work demonstrated the importance of producing bi-metallic PtSn catalysts with large Pt surfaces in order to
efficiently electro-oxidize ethanol. 相似文献