共查询到20条相似文献,搜索用时 46 毫秒
1.
Mohammad M. Hossain 《加拿大化工杂志》2012,90(4):946-955
The influence of Pd on a Co–Pd/γ‐Al2O3 heavy oil upgrading catalyst is investigated using different physicochemical and reactive Characterization techniques. Nitrogen adsorption isotherm analysis shows that the specific surface area and porosity of the support alumina is significantly decreased due to the blockage of the pores by the loaded cobalt species. The estimated activation energy of NH3 desorption is found to be less for Co–Pd/γ‐Al2O3 sample, which confirms improved acidity due to Pd. TPR experiments show that the reducibility of the catalyst is significantly improved with the presence of Pd. Higher metal dispersion and hydrogen spillover effects are the main reasons for the enhanced reducibility of the Pd promoted catalyst as revealed by the H2‐pulse chemisorptions study. When evaluated using VGO as feed stock, the Co–Pd/γ‐Al2O3 displayed superiority both in hydrodesulphurisation (HDS) and hydrocracking (HC) activities as compared to the unpromoted Co/γ‐Al2O3 catalyst. The coke deposition on the spent catalyst is also found to be low due to the Pd promotional effects. This is an encouraging result, given that higher hydrogenation activity of the catalyst can be achieved without compromising the cracking activity and sustained activity of the catalyst. 相似文献
2.
S
B Halligudi Surekha S Khaire 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2002,77(1):25-28
Hydrogenation of 4‐chloro‐2‐nitrophenol (CNP) was carried out at moderate hydrogen pressures, 7–28 atm, and temperatures in the range 298–313 K using Pt/carbon and Pd/γ‐Al2O3 as catalysts in a stirred pressure reactor. Hydrogenation of CNP under the above conditions gave 4‐chloro‐2‐aminophenol (CAP). Dechlorination to form 2‐aminophenol and 2‐nitrophenol is observed when hydrogenation of CNP is carried out above 338 K, particularly with Pd/γ‐Al2O3 catalyst. Among the catalysts tested, 1%Pt/C was found to be an effective catalyst for the hydrogenation of CNP to form CAP, exclusively. To confirm the absence of gas–liquid mass transfer effects on the reaction, the effect of stirring speed (200–1000 rpm) and catalyst loading (0.02–0.16 g) on the initial reaction rate at maximum temperature 310 K and substrate concentration (0.25 mole) were thoroughly studied. The kinetics of hydrogenation of CNP carried out using 1%Pt/C indicated that the initial rates of hydrogenation had first order dependence with respect to substrate, catalyst and hydrogen pressure in the range of concentrations varied. From the Arrhenius plot of ln rate vs 1000/T, an apparent activation energy of 22 kJ mol?1 was estimated. © 2001 Society of Chemical Industry 相似文献
3.
Lungang Chen Yulei Zhu Hongyan Zheng Chenghua Zhang Yongwang Li 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2012,87(8):1089-1097
BACKGROUND: The catalytic degradation of aqueous Fischer–Tropsch (FT) effluents to fuel gas over Ru/AC has been investigated. In order to understand the catalytic performance and stability of oxide‐supported Ru catalysts, several oxide supports (titania, zirconia, γ‐alumina and silica) were selected for study, with a focus on the hydrothermal stability of catalysts. RESULTS: The catalytic efficiency for transforming the oxygenates in aqueous FT effluents to C1–C6 alkanes decreased in the order: Ru/ZrO2~ Ru/TiO2 > Ru/SiO2 > Ru/Al2O3. The conversion of alcohols was greatly suppressed over Ru/γ‐Al2O3. The former two catalysts (Ru/ZrO2 and Ru/TiO2) exhibited enhanced efficiency and long‐term stability (400 h) relative to Ru/SiO2 and Ru/Al2O3. N2‐physisorption, XRD and SEM showed that titania and zirconia exhibited high structural stability in an aqueous environment. However, the structures of γ‐alumina and silica were unstable due to significant drop in surface area and adverse changes in surface morphology. Especially for the case of the Ru/γ‐Al2O3 catalyst, the γ‐alumina was transformed into boehmite structure after reaction, and metal leaching and carbon deposition were extensive. CONCLUSION: Ru/ZrO2 or Ru/TiO2 may be a promising alternative for degrading aqueous FT effluents due to their long‐term stability. Copyright © 2012 Society of Chemical Industry 相似文献
4.
Seon Ah Roh Soon Hwa Jung Sang Mun Jeong Sang Done Kim 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2003,78(10):1104-1109
The selective catalytic reduction (SCR) of NOx by urea as a reducing agent was carried out over fresh and sulfated CuO/γ‐Al2O3 catalysts in a fluidized‐bed reactor. The optimum temperature ranges for NO reduction on the fresh and sulfated CuO/γ‐Al2O3 catalysts were 300–350 °C and 400–450 °C, respectively. NO reduction with the sulfated CuO/γ‐Al2O3 catalyst was somewhat higher than that with the fresh CuO/γ‐Al2O3 catalyst. N2O formation increased with increasing reaction temperature. Ammonia (NH3) slip increased with increasing gas velocity and decreased with increasing reaction temperature. Copyright © 2003 Society of Chemical Industry 相似文献
5.
Fabrication of supported Pd–Ir/Al2O3 bimetallic catalysts for 2‐ethylanthraquinone hydrogenation
下载免费PDF全文
![点击此处可从《American Institute of Chemical Engineers》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Runrun Hong Yufei He Junting Feng Dianqing Li 《American Institute of Chemical Engineers》2017,63(9):3955-3965
A series of χ wt % Pd‐(1‐χ) wt % Ir (χ = 0.75, 0.50, and 0.25) catalysts supported on γ‐Al2O3 have been prepared by co‐impregnation and calcination‐reduction, and subsequently employed in the hydrogenation of 2‐ethylanthraquinone—a key step in the manufacture of hydrogen peroxide. Detailed studies showed that the size and structure of the bimetallic Pd–Ir particles vary as a function of Pd/Ir ratio. By virtue of its small metal particle size and the strong interaction between Pd and Ir, the 0.75 wt % Pd–0.25 wt % Ir/Al2O3 catalyst afforded the highest yield of H2O2, some 25.4% higher than that obtained with the monometallic 1 wt % Pd catalyst. Moreover, the concentration of the undesired byproduct 2‐ethyl‐5,6,7,8‐tetrahydroanthraquinone (H4eAQ) formed using the Pd–Ir bimetallic catalysts was much lower than that observed with the pure Pd catalyst, which can be assigned to the geometric and electronic effects caused by the introduction of Ir. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3955–3965, 2017 相似文献
6.
《Catalysis communications》2001,2(10):323-327
Hydrogenation of (E)-2-hexenal was carried out in a liquid phase using Co-based bimetallic catalysts (M–Co/Al2O3, M=Pd, Pt, Ru, Rh, Sn, Fe, or Cu). Pd–Co/Al2O3 showed the highest activity among the catalysts tested and catalyzed the hydrogenation of CC bond predominantly to produce hexanal and 1-hexanol. Pt–Co/Al2O3 was more active than monometallic Co/Al2O3 for the hydrogenation of CO bond. The excellent result, 92% selectivity to (E)-2-hexen-1-ol formation at 90% conversion, was obtained by the hydrogenation over Pt–Co/Al2O3 bimetallic catalyst. No improved activities were observed for the other bimetallic catalysts. 相似文献
7.
SO42−/ZrO2 supported on γ‐Al2O3 as a catalyst for CO2 desorption from CO2‐loaded monoethanolamine solutions
下载免费PDF全文
![点击此处可从《American Institute of Chemical Engineers》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Xiaowen Zhang Jieling Hong Helei Liu Xiao Luo Wilfred Olson Paitoon Tontiwachwuthikul Zhiwu Liang 《American Institute of Chemical Engineers》2018,64(11):3988-4001
In this work, the composite catalysts, SO42/ZrO2/γ‐Al2O3 (SZA), with different ZrO2 and γ‐Al2O3 mass ratios were prepared and used for the first time for the carbon dioxide (CO2)‐loaded monoethanolamine (MEA) solvent regeneration process to reduce the heat duty. The regeneration characteristics with five catalysts (three SZA catalysts and two parent catalysts) of a 5 M MEA solution with an initial CO2 loading of 0.5 mol CO2/mol amine at 98°C were investigated in terms of CO2 desorption performance and compared with those of a blank test. All the catalysts were characterized using X‐ray diffraction, Fourier transform infrared spectroscopy, N2 adsorption–desorption experiment, ammonia temperature programmed desorption, and pyridine‐adsorption infrared spectroscopy. The results indicate that the SZA catalysts exhibited superior catalytic activity to the parent catalysts. A possible catalytic mechanism for the CO2 desorption process over SZA catalyst was proposed. The results reveal that SZA1/1, which possesses the highest joint value of Brφnsted acid sites (BASs) and mesopore surface area (MSA), presented the highest catalytic performance, decreasing the heat duty by 36.9% as compared to the catalyst‐free run. The SZA1/1 catalyst shows the best catalytic performance as compared with the reported catalyst for this purpose. Moreover, the SZA catalyst has advantages of low cost, good cyclic stability, easy regeneration and has no effect on the CO2 absorption performance of MEA. © 2018 American Institute of Chemical Engineers AIChE J, 64: 3988–4001, 2018 相似文献
8.
Ahmad Tavasoli Mohammad Irani Reza M. Malek Abbaslou Mariane Trépanier Ajay K. Dalai 《加拿大化工杂志》2008,86(6):1070-1080
Deactivation of Co–Ru/γ‐Al2O3 Fischer–Tropsch (FT) synthesis catalyst along the catalytic bed over 850 h of time‐on‐stream (TOS) was investigated. Catalytic bed was divided into four parts and structural changes of the spent catalysts collected from each catalytic bed after FT synthesis were studied using BET, ICP, XRD, TPR, carbon determination, H2 chemisorption and oxygen titration techniques. Rapid deactivation was observed during first 200 h of FT synthesis. In this case, the deactivation rate was not dependent on the number of the catalyst active sites. It was zero order to CO conversion and independent of the size of active sites. Beyond the TOS of 200 h, the deactivation could be simulated with a power law expression: . The physical properties of the catalyst charged in 1st half of the reactor did not change significantly. Interaction of cobalt with alumina and formation of mixed oxides of the form xCoO·yAl2O3 and CoAl2O4 was increased along the catalytic bed. Percentage reducibility and dispersion decreased by 2.4–25.5% and 0.5–8.8% for the catalyst in the beds 1 and 4, respectively. Particle diameter increased by 0.8–6.1% for the catalyst in the beds 1 and 4 respectively suggesting higher rate of sintering at last catalytic bed. The amount of coke formation in the 4th catalytic bed was 6 times more than that of in bed 1. 相似文献
9.
Hydrogen production by partial oxidation and steam reforming (POSR) of n‐octane was investigated over alumina‐supported Ni and Ni‐Pd catalysts. It showed that Ni‐Pd/Al2O3 had higher activity and hydrogen selectivity than the nickel catalyst under the experimental conditions, which indicated Ni‐Pd/Al2O3 could be an effective catalyst for the production of hydrogen from hydrocarbons. 相似文献
10.
The Pd/ZrC–C and Pd/ZrO2–C catalysts with zirconium compounds ZrC or ZrO2 and carbon hybrids as novel supports for direct formic acid fuel cell (DFAFC) have been synthesized by microwave‐assisted polyol process. The Pd/ZrC–C and Pd/ZrO2–C catalysts have been characterized by X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), energy dispersive analysis of X‐ray (EDAX), transmission electron microscopy (TEM), and electrochemical measurements. The physical characteristics present that the zirconium compounds ZrC and ZrO2 may promote the dispersion of Pd nanoparticles. The results of electrochemical tests show that the activity and stability of Pd/ZrC–C and Pd/ZrO2–C catalysts show higher than that of Pd/C catalyst for formic acid electrooxidation due to anti‐corrosion property of zirconium compounds ZrC, ZrO2, and metal–support interaction between Pd nanoparticles and ZrC, ZrO2. The Pd/ZrC–C catalyst displays the best performance among the three catalysts. The peak current density of formic acid electrooxidation on Pd/ZrC–C electrode is nearly 1.63 times of that on Pd/C. The optimal mass ratio of ZrC to XC‐72 carbon is 1:1 in Pd/ZrC–C catalyst with narrower particle size distribution and better dispersion on surface of the mixture support, which exhibits the best activity and stability for formic acid electrooxidation among all the samples. 相似文献
11.
Evaluation of the performance of catalytic oxidation of VOCs by a mixed oxide at a semi‐pilot scale†
Rita Ribeiro Nicolas Heymans Marie‐Eve Duprez Renaud Cousin Stphane Siffert Christophe Poupin Diane Thomas Andr Decroly Guy De Weireld 《加拿大化工杂志》2021,99(1):108-119
Volatile organic compounds (VOCs) are one of the main contributors to air pollution. To reduce anthropogenic emissions, it is necessary to improve existing techniques such as catalytic oxidation through the development of new cost‐effective catalysts. Although many studies deal with the development and testing of new materials, most are performed at laboratory scale, of which only a few study mixtures of VOCs. To assess their viability for industrial applications, further tests are required, namely, mixture tests at intermediate scale in relevant environment and extrapolated on an industrial scale. In this work, the catalytic performance of a new mixed oxide Co‐Al‐Ce was investigated towards the oxidation of the n‐butanol and toluene on a semi‐pilot scale (TRL 4). Single component and mixture experiments were performed for several concentrations at a fixed flow rate. A commercial catalyst Pd/γ‐Al2O3 was used as the benchmark to evaluate the performance of the mixed oxide. The Co‐Al‐Ce catalyst enables complete oxidation of n‐butanol at the same temperature as the reference catalyst. Moreover, it provides a better selectivity for n‐butanol, while providing an equivalent one for the oxidation of toluene. In mixtures, the presence of n‐butanol promotes the oxidation of toluene for both catalysts but more significantly for the Co‐Al‐Ce catalyst. The presence of toluene inhibits the oxidation of n‐butanol for the Co‐Al‐Ce and promotes it for high conversions of n‐butanol for the Pd/γ‐Al2O3 catalyst. 相似文献
12.
Ying Peng Minghui Dong Xiangkun Meng Baoning Zong Jinli Zhang 《American Institute of Chemical Engineers》2009,55(3):717-725
Magnetic NiSO4/γ‐Al2O3 catalysts were prepared by impregnating NiSO4 solutions onto the γ‐Al2O3 support containing a magnetic material of Fe3O4. Characterization by XRD, NH3‐TPD, and thermal analysis showed that the magnetic NiSO4/γ‐Al2O3 catalyst with a nickel content of 7.0% by weight had a monolayer dispersion of NiSO4 and the largest number of moderate strength acid sites, and a high specific saturation magnetization. The magnetic catalyst was evaluated for light FCC gasoline olefin oligomerization in both fixed‐bed and magnetically stabilized bed (MSB) reactors. Comparing with that in the fixed‐bed reactor, the optimal reaction temperature in the MSB lowered to 443 K, and its space velocity ranged broadly from 2.0 to 6.0 h?1. The sulfur‐free diesel distillate produced by operation of the MSB for 100 h had higher cetane number and good low‐temperature flow property, which illuminates a promising application of the MSB to manufacture clean diesel fuels with high productivity and flexibility. © 2009 American Institute of Chemical Engineers AIChE J, 2009 相似文献
13.
C. M. Balonek J. L. Colby L. D. Schmidt 《American Institute of Chemical Engineers》2010,56(4):979-988
The millisecond autothermal reforming of benzene, toluene, ethylbenzene, cumene, and styrene were independently studied over five noble metal‐based catalysts: Pt, Rh, Rh/γ‐Al2O3, Rh–Ce, and Rh–Ce/γ‐Al2O3, as a function of carbon‐to‐oxygen feed ratio. The Rh–Ce/γ‐Al2O3 catalyst exhibited the highest feedstock conversion as well as selectivities to both synthesis gas and hydrocarbon products (lowest selectivities to H2O and CO2). Experimental results demonstrate a high stability of aromatic rings within the reactor system. Benzene and toluene seem to react primarily heterogeneously, producing only syngas and combustion products. Ethylbenzene and cumene behaved similarly, with higher conversions than benzene and toluene, and high product selectivity to styrene, likely due to homogeneous reactions involving their alkyl groups. Styrene exhibited low conversions over Rh–Ce/γ‐Al2O3, emphasizing the stability of styrene in the reactor system. © 2009 American Institute of Chemical Engineers AIChE J, 2009 相似文献
14.
Shun‐Li Hao Wei‐Cai Peng Ning Zhao Fu‐Kui Xiao Wei Wei Yu‐Han Sun 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2010,85(11):1499-1503
BACKGROUND: Crude glycerol will increase to over 400 million L year?1, and the market is likely to become saturated due to the limited demand for glycerol. The main aim of this work is to develop a novel process for the sustainable conversion of glycerol to 1,2‐propanediol (l,2‐PD). RESULTS: Cu‐H4SiW12O40/Al2O3 catalysts with different H4SiW12O40 (STA) loadings were prepared for the hydrogenolysis of glycerol to produce l,2‐PD in liquid phase. At 513 K, 6 MPa and LHSV of 0.9 h?1 in 10% (w/w) glycerol aqueous solutions, the catalyst with 5% (w/w) STA showed the best performance with 90.1% of glycerol conversion and 89.7% selectivity to l,2‐PD. More important, both the initial glycerol conversion and l,2‐PD selectivity were maintained over 250 h. CONCLUSION: l,2‐PD can be continuously produced with high yields via the liquid phase hydrogenolysis of glycerol over Cu‐H4SiW12O40/Al2O3. Furthermore, the characterization indicated that catalyst acidity could be greatly modified by STA, which promoted Cu reducibility. It was also found that hydrogenolysis could be favored by a bi‐functional catalyst with the appropriate amount of both acid and metal sites. Copyright © 2010 Society of Chemical Industry 相似文献
15.
The reaction behavior and mechanistic aspects of the selective methanation of CO over two supported Ru catalysts, a Ru/zeolite catalyst and a Ru/Al2O3 catalyst, in CO2 containing reaction gas mixtures were investigated by temperature-screening measurements, kinetic measurements and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) measurements. The influence of other components present in realistic reformate gases, such as H2O and high amounts of CO2, on the reaction behavior was evaluated via measurements in increasingly realistic gas mixtures. Temperature screening and kinetic measurements revealed a high activity of both catalysts, with the Ru mass-normalized activity of the Ru/zeolite catalyst exceeding that of the Ru/Al2O3 catalyst by about one order of magnitude. Approaching more realistic conditions, the conversion–temperature curve was shifted slightly upwards for the Ru/Al2O3 catalyst, whereas for the Ru/zeolite catalyst it remained unaffected. The selectivity was highest for the Ru/zeolite catalyst, where in parallel to full conversion of CO the conversion of CO2 remained below 10% over a 40 °C temperature window. During selective methanation on the Ru/Al2O3 catalyst, CO2 was converted even though CO was not completely removed from the feed. Transient DRIFTS measurements, following the build-up and decomposition of adsorbed surface species in different reaction atmospheres and in the corresponding CO-free gas mixtures, respectively, provide information on the formation and removal/stability of the respective adsorbed species and, by comparison with the kinetic data, on their role in the reaction mechanism. Consequences on the mechanism and physical reasons underlying the observed selectivity are discussed. 相似文献
16.
Mi Yeon Byun Ji Sun Kim Dae-Won Park Man Sig Lee 《Korean Journal of Chemical Engineering》2018,35(5):1083-1088
We investigated the influence of the calcination temperature on the structural properties of Al2O3 and how the resultant Al2O3 support affects the characteristics of Pd/Al2O3 catalysts. Al2O3 pretreated at different calcination temperatures ranging from 500 °C to 1,150 °C, was used as catalyst supports. The Pd/Al2O3 catalysts were prepared by a deposition-precipitation method using a pH 7.5 precursor solution. Characterization of the prepared Pd/Al2O3 catalysts was performed by X-ray diffraction (XRD), N2-physisorption, CO2-temperature programmed desorption (TPD), CO-chemisorption, and field emission-transmission electron microscopic (FE-TEM) analyses. The CO-chemisorption results showed that the Pd catalyst with the Al2O3 support calcined at 900 °C, Pd/Al2O3 (900), had the highest and most uniformly dispersed Pd particles, with a Pd dispersion of 29.8%. The results suggest that the particle size and distribution of Pd are related to the phase transition of Al2O3 and the ratio of isolated tetrahedral to condensed octahedral coordination sites (i.e., functional groups), where the tetrahedral sites coordinate more favorably with Pd. 相似文献
17.
Zhiming Zhou Tianying Zeng Zhenmin Cheng Weikang Yuan 《American Institute of Chemical Engineers》2011,57(8):2198-2206
A novel Pd/Al2O3 catalyst with the hierarchically macro‐mesoporous structure was prepared and applied to the selective hydrogenation of pyrolysis gasoline. The alumina support possessed a unique structure of hierarchical mesopores and macropores. The as‐prepared and calcined alumina were characterized by X‐ray diffraction, N2 adsorption‐desorption, and scanning electron microscopy. It showed that the hierarchically porous structure of the alumina was well preserved after calcination at 1073 K, indicating high thermal stability. The 1073 K calcined alumina was impregnated with palladium metal and compared with a commercial catalyst without macrochannels. Both the catalytic activity and the hydrogenation selectivity of the novel Pd/Al2O3 catalyst were higher than those of the commercial Pd/Al2O3 catalyst. In addition, apparent reaction activation energies obtained with the novel catalyst for model pyrolysis gasoline were 46–81% higher than those with the commercial catalyst. The results adequately demonstrated the enhanced mass transfer characteristics of the novel macro‐mesostructured catalyst. © 2010 American Institute of Chemical Engineers AIChE J, 2011 相似文献
18.
Shaobin Wang G
Q Lu 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2000,75(7):589-595
Catalytic reforming of methane with carbon dioxide was studied in a fixed‐bed reactor using unpromoted and promoted Ni/γ‐Al2O3 catalysts. The effects of promoters, such as alkali metal oxide (Na2O), alkaline‐earth metal oxides (MgO, CaO) and rare‐earth metal oxides (La2O3, CeO2), on the catalytic activity and stability in terms of coking resistance and coke reactivity were systematically examined. CaO‐, La2O3‐ and CeO2‐promoted Ni/γ‐Al2O3 catalysts exhibited higher stability whereas MgO‐ and Na2O‐promoted catalysts demonstrated lower activity and significant deactivation. Metal‐oxide promoters (Na2O, MgO, La2O3, and CeO2) suppressed the carbon deposition, primarily due to the enhanced basicities of the supports and highly reactive carbon species formed during the reaction. In contrast, CaO increased the carbon deposition; however, it promoted the carbon reactivity. © 2000 Society of Chemical Industry 相似文献
19.
Ke Zhang Xiaotong Wei Zebao Rui Yongdan Li Y. S. Lin 《American Institute of Chemical Engineers》2009,55(3):630-639
Thin palladium membranes of different thicknesses were prepared on sol‐gel derived mesoporous γ‐alumina/α‐alumina and yttria‐stabilized zirconia/α‐alumina supports by a method combining sputter deposition and electroless plating. The effect of metal‐support interface on hydrogen transport permeation properties was investigated by comparing hydrogen permeation data for these membranes measured under different conditions. Hydrogen permeation fluxes for the Pd/γ‐Al2O3/α‐Al2O3 membranes are significantly smaller than those for the Pd/YSZ/α‐Al2O3 membranes under similar conditions. As the palladium membrane thickness increases, the difference in permeation fluxes between these two groups of membranes decreases and the pressure exponent for permeation flux approaches 0.5 from 1. Analysis of the permeation data with a permeation model shows that both groups of membranes have similar hydrogen permeability for bulk diffusion, but the Pd/γ‐Al2O3/α‐Al2O3 membranes exhibit a much lower surface reaction rate constant with higher activation energy, due possibly to the formation of Pd‐Al alloy, than the Pd/YSZ/α‐Al2O3 membranes. © 2009 American Institute of Chemical Engineers AIChE J, 2009 相似文献
20.
Emilio A. Cepeda Unai Iriarte-Velasco Beatriz Calvo Irene Sierra 《Journal of the American Oil Chemists' Society》2016,93(5):731-741
This work is aimed at evaluating the performance of several catalysts in the partial hydrogenation of sunflower oil. The catalysts are composed of noble (Pd and Pt) and base metals (Ni, Co and Cu), supported on both silica and alumina. The following order can be proposed for the effect of the metal on the hydrogenation activity: Pd > Pt > Ni > Co > Cu. At a target iodine value of 70 (a typical value for oleomargarine), the production of trans isomers is minimum for supported nickel catalysts (25.7–32.4 %, depending on the operating conditions). Regarding the effect of the support, Al2O3 allows for more active catalysts based on noble metals (Pd and Pt) and Co, the effect being much more pronounced for Pt. Binary mixtures of catalysts have been studied, in order to strike a balance between catalyst activity and product distribution. The results evidence that Pd/Al2O3–Co/SiO2 mixture has a good balance between activity and selectivity, and leads to a very low production of trans isomers (11.8 %) and a moderate amount of saturated stearic acid (13.5 %). Consequently, the utilization of cobalt‐based catalysts (or the addition of cobalt to other metallic catalysts) could be considered a promising alternative for the hydrogenation of edible oil. 相似文献