Manganese-promoted Rh/Al2O3 for C2-oxygenates synthesis from syngas

Ojeda, Manuel; Granados, M. Lòpez; Rojas, Sergio; Terreros, Pilar; García-García, Francisco J.; Fierro, J.L.G.

doi:10.1016/j.apcata.2003.10.033

Cited by 129 publications

(62 citation statements)

References 46 publications

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“…The adsorbed CO firstly could be partially hydrogenated into C1 oxygenate transitional species (such as HCO, H 2 CO, or HCOH), and then these species could either be completely hydrogenated into methanol, or be hydrogenated by means of C-O bond crack and formed -CH x , which was the precursor for the carbon-chain-growth reaction via CO insertion, and for C 2 + oxygenates formation [1,3]. The results of CO-TPD suggested that the catalytic capacity for CO activation and carbon-chain-growth reaction were improved over the plasma promoted catalysts [2,7].…”

Section: Characterizationmentioning

confidence: 99%

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mentioning

confidence: 99%

“…catalytic performance of rhodium-based catalysts have been comprehensively studied: the promoters, including manganese, ceria, iron, vanadium, titanium, iridium and lithium, etc., the supporters, including SiO 2 , Al 2 O 3 , ZrO 2 , and NaY zeolites, and the novel preparation processes, including sol-gel and micro-emulsion [1][2][3].…”

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confidence: 99%

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Effect of glow discharge plasma on rhodium-based catalyst for oxygenates synthesis

Huang

Chu

Jun-qiang

et al. 2007

Front. Chem. Eng. China

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catalytic performance of rhodium-based catalysts have been comprehensively studied: the promoters, including manganese, ceria, iron, vanadium, titanium, iridium and lithium, etc., the supporters, including SiO 2 , Al 2 O 3 , ZrO 2 , and NaY zeolites, and the novel preparation processes, including sol-gel and micro-emulsion [1][2][3].Glow discharge plasma, as an ionized non-equilibrium system applied in catalysts preparation, can endow catalysts with a modification in their surface properties, and a disorder in their crystallite. On supported catalysts, glow discharge plasma can modify the active compounds distribution and the interaction among the supporter, additives and active compounds. Thus, this method can improve the activity and selectivity in catalytic performance [4][5][6].In this paper, the plasma-promoted Rh-Ce-Mn/SiO 2 catalysts were prepared, and the characterizations such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), H 2 temperature-programmed reduction (H 2 -TPR), H 2 temperature-programmed desorption (H 2 -TPD) and CO temperature-programmed desorption (CO-TPD) were utilized to reveal the effect of plasma on active components dispersion, and on reducibility and adsorption capacity. The oxygenate synthesis from CO hydrogenation was carried out as a model reaction to measure the catalytic performance. Experimental Catalysts preparationThe catalysts were prepared by co-impregnation of silica gel with appropriate solutions of RhCl 3 , Ce(NO 3 ) 3 and Mn(NO 3 ) 2 , followed by drying at 110°C for 10 h. Then the sample calcined at 350°C for 3 h in air was obtained and called as RCM/S. The other precursors were put into the discharging tube of GP062DL3 plasma generator, and then treated by glow discharge plasma in nitrogen for 45 min, followed by Abstract Rhodium-based catalysts were prepared by impregnation, treated with glow discharge plasma, characterized by X-ray diffraction, X-ray photoelectron spectroscopy, H 2 temperature-programmed reduction, H 2 temperatureprogrammed desorption and CO temperature-programmed desorption, and investigated for oxygenate synthesis from CO hydrogenation. Based on the characterization results, plasma treatment endowed the samples with smaller particle size, higher dispersion of active components, and an enrichment of active components on the surface as well. As a result, the reducibility and adsorption properties were modified. In catalytic tests, the catalytic activity for CO hydrogenation over the samples treated by plasma was improved remarkably: the conversion of CO and the yield of oxygenates increased at most by a factor of 78.62% and 51.96%, respectively, while the selectivity of ethanol and methanol in the oxygenates was enhanced as well.

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Section: Characterizationmentioning

confidence: 99%

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Effect of glow discharge plasma on rhodium-based catalyst for oxygenates synthesis

Huang

Chu

Jun-qiang

et al. 2007

Front. Chem. Eng. China

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“…For example, Hu et al 16 observed that methane selectivity are in the range of 34 to 54%. Ojeta et al 17 found that methane selectivity increased from 22 to 32% as the reaction temperature increased from 513 to 533 K.…”

Section: Co + H 2 Reaction Network Developmentmentioning

confidence: 99%

Rh-Based Mixed Alcohol Synthesis Catalysts: Characterization and Computational Report

Albrecht¹,

Glezakou²,

Rousseau³

et al. 2013

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Executive SummaryThe U.S. Department of Energy is conducting a program focused on developing a process for the conversion of biomass to bio-based fuels and co-products. The lignocellulosic biomass feedstock is first gasified to produce a product known as synthesis gas (syngas), which consists of H 2 and CO. The syngas stream is subsequently converted thermochemically within a temperature range of 240 to 330°C and at elevated pressure (e.g., 1200 psig) over a catalyst. Ethanol is the desired reaction product, although other side compounds are produced, including C 3 to C 5 alcohols; higher (i.e., greater than C 1 ) oxygenates such as methyl acetate, ethyl acetate, acetic acid and acetaldehyde; and higher hydrocarbon gases such as methane, ethane/ethene, propane/propene, etc. Saturated hydrocarbon gases (especially methane) are undesirable because they represent a diminished yield of carbon to the desired ethanol product and represent compounds that must be steam reformed at high energy cost to reproduce CO and H 2 . Ethanol produced by the thermochemical reaction of syngas could be separated and blended directly with gasoline to produce a liquid transportation fuel. Additionally, higher oxygenates and unsaturated hydrocarbon side products such as olefins also could be further processed to liquid fuels.The goal of the current project is the development of an Rh-based catalyst with high activity and selectivity to C 2 + oxygenates. Since the program began in 2005, significant improvements in activity and selectivity to the Rh-based catalyst have been achieved through empirical catalyst screening (e.g., support and promoter screening) and operational parametric screening. This report chronicles an effort to characterize numerous supports and catalysts to identify particular traits that could be correlated with the most active and/or selective catalysts. Characterization techniques were chosen to identify the properties of a variety of supports and catalysts. Carbon and silica were the general classes of supports analyzed. Analysis procedures used for several supports are identified below:• Ash concentration of the carbon supports • Elemental composition via inductively coupled plasma• Surface area (Brunauer-Emmett-Teller) and pore size distribution (Barrett-Joyner-Halenda) via N 2 adsorption and desorption• Surface acidity measurements of the silica supports via NH 3 desorption• Carbon support surface functionality characterization via thermogravimetric analysis with mass spectrometer analysis of the effluent gas• Diffuse reflectance infrared Fourier transform spectroscopy analysis of selected carbon supports to identify surface functionality.Generally, analyses provided guidance in the selection of acceptable catalyst supports. For example, supports with high surface areas due to a high number of micropores were generally found to be poor at producing oxygenates, possibly because of mass transfer limitations of the products formed out of the micropores.A number of prepared catalysts (i.e., with Rh and other metal p...

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“…These include Rh-based catalysts [8], modified high-temperature and low-temperature methanol synthesis catalysts based on ZnO/Cr 2 O 3 and Cu/ZnO/Al 2 O 3 [9], respectively, modified Fischer-Tropsch catalysts based on Co, Fe and Ru [10], and non-sulfide [11] and sulfide Mo-based catalysts [12][13][14]. Among these catalysts, molybdenum sulfide (MoS 2 ) catalysts have attracted much interest because of their higher selectivity to alcohols and excellent resistance to poisoning from sulfur in the feed gas [15][16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Alcohols and Alkanes from CO and H2 over MoS2/γ-Al2O3 Catalyst in a Packed Bed with Continuous Flow

et al. 2012

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Effects of reaction conditions on the production of alcohols (AOHs) and alkanes (Alk) from CO and H 2 , which can be obtained from the gasification of biomass, using a molybdenum sulfide (MoS 2 )-based catalyst of MoS 2 /γ-Al 2 O 3 were studied. A high-pressure fixed packed bed (HPFPB) was employed to carry out the reaction. The results indicate that the conversion of CO (X CO ) and specific production rates of alcohol (SPR AOH ) and alkane (SPR Alk ) are highly depended on temperature (T). In T = 423-573 K, maximum yield of alcohols (Y AOH ) and SPR AOH occur at T = 523 K. In the meantime, well performance gives the selectivity of ethanol (S EtOH ) of 52.0 C%. For the studies on varying H 2 /CO mole ratio (M H/C ) from 1 to 4 at 523 K, the appropriate M H/C to produce EtOH is 2, giving higher ratios of SPR AOH /SPR Alk and Y AOH /Y Alk than those with other M H/C . As for varying the total gas flow rates (Q G ) of 300, 450, 600 to 900 cm 3 min −1 tested at T = 523 K and M H/C = 2, the lower Q G provides longer reaction time (or gaseous retention time, t R ) thus OPEN ACCESSEnergies 2012, 5 4148 offering higher X CO , however lower productivity. For setting pressure (P ST ) = 225-540 psi, a supply of higher pressure is equivalent to providing a larger amount of reactants into the reaction system, this thus suggests the use of higher P ST should give both higher X CO and productivity. The assessment of the above results indicates that the MoS 2 /γ-Al 2 O 3 catalyst favors the production of alcohols over alkanes, especially for ethanol. The information obtained is useful for the proper utilization of biomass derived gases of CO and H 2 .

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Manganese-promoted Rh/Al2O3 for C2-oxygenates synthesis from syngas

Cited by 129 publications

References 46 publications

Effect of glow discharge plasma on rhodium-based catalyst for oxygenates synthesis

Effect of glow discharge plasma on rhodium-based catalyst for oxygenates synthesis

Rh-Based Mixed Alcohol Synthesis Catalysts: Characterization and Computational Report

Synthesis of Alcohols and Alkanes from CO and H2 over MoS2/γ-Al2O3 Catalyst in a Packed Bed with Continuous Flow

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