Selective Hydrogenation of Acetylene to Ethylene Over Nanosized Gold and Palladium Supported Catalysts

2020 ◽  
Vol 20 (9) ◽  
pp. 5800-5803 ◽  
Author(s):  
Gyeongmin Lee ◽  
Woon-Jo Jeong ◽  
Ho-Geun Ahn
Keyword(s):  
Selective Hydrogenation ◽  
Supported Catalysts ◽  
Fixed Bed ◽  
Raw Material ◽  
Fixed Bed Reactor ◽  
Selective Hydrogenation Of Acetylene ◽  
Metal Support Interaction ◽  
Metal Support ◽  
Polyethylene Production ◽  
Ethylene Selectivity

Ethylene, the main raw material for polyethylene production, is a by-product produced by thermally decomposing naphtha and it contains a small amount of acetylene. The acetylene reacts as a permanent catalyst poison for the ethylene polymerization catalyst. In this study, we wanted to improve the acetylene conversion and the ethylene selectivity by selective hydrogenation of acetylene for removing acetylene contained in ethylene. Catalyst was prepared by loading nanosized gold (Au) and palladium (Pd) particles on support (Al2O3, TiO2). Deposition order Au and Pd particles was changed. The activity of the catalyst was investigated using a flow-typed fixed bed reactor under atmospheric pressure. Au and Pd particles deposited on TiO2 were oxidized to Au2O3 and PdO due to strong metal support interaction (SMSI). It was considered that the Au/Pd/Al2O3 catalyst was more active than the Pd/Au/Al2O3 catalyst due to the formation of the interface between Au particles and Pd particles (or support). But Pd/Au/Al2O3 catalyst is considered to have poor activity because Pd particles cover part of the interface between Au and the support. Au/Pd/Al2O3 catalyst showed the best catalytic activity, and acetylene conversion and ethylene selectivity were 100% and about 80% at 40 °C, respectively.

Catalytic Vapor Phase Nitroxidation of p-Xylene: a New Route for Synthesis of Terephthalic Acid and Poly(ethylene Terephthalate)

1992 ◽  
Vol 62 (10) ◽  
pp. 603-607
Author(s):  
Vandana Kala ◽  
R. Prasad ◽  
A. L. Sharma ◽  
J. Mathew
Keyword(s):  
Ethylene Terephthalate ◽  
Oxide Catalyst ◽  
Fixed Bed ◽  
Atomic Ratio ◽  
Fixed Bed Reactor ◽  
Effect Of Temperature ◽  
Poly Ethylene Terephthalate ◽  
Metal Support Interaction ◽  
Metal Support ◽  
Poly Ethylene

We have examined catalytic transformation of p-xylene into terephthalonitrile with nitric oxide (NO) over an aluminium oxide-supported ferric oxide catalyst using a fixed bed reactor in a temperature range of 320-460°c under atmospheric pressure. We achieved a maximum conversion of 80% with an Al2O3:Fe2O3 catalyst having an Al:Fe atomic ratio of nearly 1:1 at a temperature of 360°c with a NO: p-xylene mole ratio of 54.60. We studied the effect of temperature and NO: p-xylene mole ratio on the conversion to terephthalonitrile. Using Mössbauer and IR spectra of the catalysts, we concluded that Al2O3 not only provides a larger surface for the iron oxide catalyst, but also increases its activity by interacting with Fe2O3 and upholds the theory of metal support interaction.

Hydrogen Production via Methane Decomposition Using Ni and Ni-Cu Catalysts Supported on MgO, Al2O3 and MgAl2O4

2010 ◽  
Vol 1279 ◽  
Author(s):  
José F. Pola ◽  
Miguel A. Valenzuela ◽  
Iván A. Córdova ◽  
J. A. Wang
Keyword(s):  
Bimetallic Catalysts ◽  
Fixed Bed ◽  
Decomposition Reaction ◽  
Methane Decomposition ◽  
Fixed Bed Reactor ◽  
Magnesium Aluminate ◽  
Alloy Formation ◽  
Support Interaction ◽  
Metal Support Interaction ◽  
Metal Support

AbstractNi (10%) and Ni-Cu (50 and 25%, respectively) catalysts supported on alumina, magnesia and magnesium aluminate were synthesized. The characterization was carried out by X-ray diffraction, nitrogen physisorption, temperature programmed-reduction, Raman spectroscopy and SEM. The catalysts were tested in the methane decomposition reaction using a tubular fixed bed reactor operated in the range of 500-580°C under atmospheric pressure. A higher activity was observed with the bimetallic catalysts supported on alumina and magnesium aluminate. These results were explained in terms of Ni-Cu alloy formation and weak metal-support interaction. In the case of monometallic catalysts, a strong metal-support interaction was detected, which revealed the lowest activity and stability compared with the bimetallic catalysts. The formed carbon was a combination of amorphous and graphite.

scholarly journals Effect of Calcination Temperature on Hydrogen Production via Ethanol Dry Reforming Over Ni/Al2O3 Catalyst

2018 ◽  
Vol 4 (1) ◽  
pp. 5 ◽  
Author(s):  
Kasim Samsudeen ◽  
Al fatesh Ahmed ◽  
Mohammad Yahya ◽  
Aidid Ahmed ◽  
Fakeeha Anis
Keyword(s):  
Fixed Bed ◽  
Dry Reforming ◽  
Fixed Bed Reactor ◽  
Ethanol Conversion ◽  
Impregnation Method ◽  
Average Value ◽  
Calcination Temperatures ◽  
Metal Support Interaction ◽  
Metal Support ◽  
Different Temperatures

Ni/Al2O3 catalysts were prepared by the wet-impregnation method and calcined at different temperatures (500°C, 600°C and 700°C) to obtain NiAl-1, NiAl-2 and NiAl-3 respectively. NiAl-1, NiAl-2, NiAl-3 represent catalysts calcined at 500°C, 600°C and 700°C respectively. The catalysts were characterized using different techniques, XRD, BET and TGA. XRD results revealed the presence of NiO phase on all the catalysts during calcination, however, the presence of spinel, NiAl2O4, was more pronounced on the catalyst calcined at 600°C (i.e. NiAl-2), indicating the existence of strong metal-support interaction. BET results showed that NiAl-1 has the highest surface area of about 190cm2/g.  All the catalysts were tested for ethanol dry reforming in a tubular stainless steel fixed-bed reactor at 700°C and CO2/ethanol ratio of 3 under atmospheric pressure and were evaluated in terms of reactants conversion and selectivity of H2 to see the effect of the different calcination temperatures on the catalysts’ activities. Ethanol conversion was 100% for all the three catalysts and NiAl-2 has the highest CO2 conversion with an average value of about 57%. The three catalysts have almost the same performance in terms of H2 selectivity. The presence of multi-walled carbon nanofibers (MWCNFs) were confirmed on all the catalysts as revealed by the TGA result. The catalyst calcined at 600°C (i.e. NiAl-2) displayed the best relative catalytic activity

Co-processing of hydrodeoxygenation and hydrodesulfurization of phenol and dibenzothiophene with NiMo/Al2O3–ZrO2 and NiMo/TiO2–ZrO2 catalysts

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jesús Andrés Tavizón Pozos ◽  
Gerardo Chávez Esquivel ◽  
Ignacio Cervantes Arista ◽  
José Antonio de los Reyes Heredia ◽  
Víctor Alejandro Suárez Toriello
Keyword(s):  
Active Sites ◽  
Reaction Rate ◽  
Supported Catalysts ◽  
Initial Reaction Rate ◽  
Initial Reaction ◽  
Competition Effect ◽  
Support Interaction ◽  
Highly Active ◽  
Metal Support Interaction ◽  
Metal Support

Abstract The influence of Al2O3–ZrO2 and TiO2–ZrO2 supports on NiMo-supported catalysts at a different sulfur concentration in a model hydrodeoxygenation (HDO)-hydrodesulfurization (HDS) co-processing reaction has been studied in this work. A competition effect between phenol and dibenzothiophene (DBT) for active sites was evidenced. The competence for the active sites between phenol and DBT was measured by comparison of the initial reaction rate and selectivity at two sulfur concentrations (200 and 500 ppm S). NiMo/TiO2–ZrO2 was almost four-fold more active in phenol HDO co-processed with DBT than NiMo/Al2O3–ZrO2 catalyst. Consequently, more labile active sites are present on NiMo/TiO2–ZrO2 than in NiMo/Al2O3–ZrO2 confirmed by the decrease in co-processing competition for the active sites between phenol and DBT. DBT molecules react at hydrogenolysis sites (edge and rim) preferentially so that phenol reacts at hydrogenation sites (edge and edge). However, the hydrogenated capacity would be lost when the sulfur content was increased. In general, both catalysts showed similar functionalities but different degrees of competition according to the highly active NiMoS phase availability. TiO2–ZrO2 as the support provided weaker metal-support interaction than Al2O3–ZrO2, generating a larger fraction of easily reducible octahedrally coordinated Mo- and Ni-oxide species, causing that NiMo/TiO2–ZrO2 generated precursors of MoS2 crystallites with a longer length and stacking but with a higher degree of Ni-promotion than NiMo/Al2O3–ZrO2 catalyst.

Engineering the geometric and electronic structure of Ru via Ru-TiO2 interaction for enhanced selective hydrogenation

2022 ◽  
Author(s):  
Jian-guo Wang ◽  
Qiang Zhou ◽  
Zijiang Zhao ◽  
Zihao Yao ◽  
Zhongzhe Wei ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Chemical Reactions ◽  
Selective Hydrogenation ◽  
Oxygen Vacancies ◽  
Reduction Method ◽  
Support Interaction ◽  
Important Chemical ◽  
Metal Support Interaction ◽  
Metal Support

Modulation of the metal-support interaction plays a key role in many important chemical reactions. Here, by adjusting the reduction method of the catalyst and introducing oxygen vacancies in TiO2 to...

The effect of potassium on Cu/Al2O3 catalysts for the hydrogenation of 5-hydroxymethylfurfural to 2,5-bis(hydroxymethyl)furan in a fixed-bed reactor

2018 ◽  
Vol 8 (23) ◽  
pp. 6091-6099 ◽  
Author(s):  
Danxin Hu ◽  
Hualei Hu ◽  
Hao Zhou ◽  
Guozheng Li ◽  
Chunlin Chen ◽  
...  
Keyword(s):  
Selective Hydrogenation ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Highly Efficient

The highly efficient selective hydrogenation of 5-hydroxymethylfurfural (HMF) to 2,5-bis(hydroxymethyl)furan (BHMF) was achieved in a fixed-bed reactor by using inexpensive potassium-doped Cu/Al2O3 catalysts.

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