{CeO2/Bi2Mo1−xRuxO6} and {Au/Bi2Mo1−xRuxO6} Catalysts for Low-Temperature CO Oxidation

Nowadays, one of the most important challenges that humanity faces is to find alternative ways of reducing pollutant emissions. CeO2/Bi2Mo1−xRuxO6 and Au/Bi2Mo1−xRuxO6 catalysts were prepared to efficiently transform carbon monoxide (CO) to carbon dioxide (CO2) at low temperatures. The systems were prepared in a two-step process. First, Bi2Mo1−xRuxO6 supports were synthesized through the hydrothermal procedure under microwave heating. Then, CeO2 was deposited on Bi2Mo1−xRuxO6 using the wet impregnation method, while the incipient impregnation method was selected to deposit gold nanoparticles. The CeO2/Bi2Mo1−xRuxO6 and Au/Bi2Mo1−xRuxO6 catalysts were characterized using SEM microscopy and XRD. Furthermore, energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy were used. Tests were carried out for the supported catalysts in CO oxidation, and high conversion values, nearing 100%, was observed in a temperature range of 100 to 250 °C. The results showed that the best system was the Au/Bi2Mo0.95Ru0.05O6 catalyst, with CO oxidation starting at 50 °C and reaching 100% conversion at 186 °C.

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Catalytic activity of nanostructured Au: Scale effects versus bimetallic/bifunctional effects in low-temperature CO oxidation on nanoporous Au

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.4.13 ◽

2013 ◽

Vol 4 ◽

pp. 111-128 ◽

Cited By ~ 29

Author(s):

Lu-Cun Wang ◽

Yi Zhong ◽

Haijun Jin ◽

Daniel Widmann ◽

Jörg Weissmüller ◽

...

Keyword(s):

Catalytic Activity ◽

Low Temperature ◽

Co Oxidation ◽

Surface Area ◽

Photoelectron Spectroscopy ◽

Scale Effects ◽

Structural Parameters ◽

Kinetic Measurements ◽

X Ray ◽

Low Temperature Co Oxidation

The catalytic properties of nanostructured Au and their physical origin were investigated by using the low-temperature CO oxidation as a test reaction. In order to distinguish between structural effects (structure–activity correlations) and bimetallic/bifunctional effects, unsupported nanoporous gold (NPG) samples prepared from different Au alloys (AuAg, AuCu) by selective leaching of a less noble metal (Ag, Cu) were employed, whose structure (surface area, ligament size) as well as their residual amount of the second metal were systematically varied by applying different potentials for dealloying. The structural and chemical properties before and after 1000 min reaction were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The catalytic behavior was evaluated by kinetic measurements in a conventional microreactor and by dynamic measurements in a temporal analysis of products (TAP) reactor. The data reveal a clear influence of the surface contents of residual Ag and Cu species on both O2 activation and catalytic activity, while correlations between activity and structural parameters such as surface area or ligament/crystallite size are less evident. Consequences for the mechanistic understanding and the role of the nanostructure in these NPG catalysts are discussed.

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Catalytic Combustion of Dimethyl Disulfide on Bimetallic Supported Catalysts Prepared by the Wet-Impregnation Method

10.20944/preprints201911.0191.v1 ◽

2019 ◽

Author(s):

Junan Gao ◽

Song Gao ◽

Jun Wei ◽

Hong Zhao ◽

Jie Zhang

Keyword(s):

Synergistic Effect ◽

Catalytic Combustion ◽

Supported Catalysts ◽

Dimethyl Disulfide ◽

Catalytic Performance ◽

Sulfur Poisoning ◽

Impregnation Method ◽

Promoting Effect ◽

Wet Impregnation ◽

Wet Impregnation Method

In this paper, the catalytic combustion of DMDS (dimethyl disulfide, CH3SSCH3) over bimetallic supported catalysts were investigated. It was confirmed that Cu/γ-Al2O3-CeO2 showed best catalytic performance among the five single-metal catalysts. Furthermore, six different metals were separately added into Cu/γ-Al2O3-CeO2 to investigate the promoting effect. The experiments revealed Pt as the most effective promoter and the the best catalytic performance was achieved as the adding amount of 0.3 wt%. The characterization results indicated that high activity and resistance to sulfur poisoning of Cu-Pt/γ-Al2O3-CeO2 could be attributed to the synergistic effect between Cu and Pt.

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High Active and Selective Ni/CeO2–Al2O3 and Pd–Ni/CeO2–Al2O3 Catalysts for Oxy-Steam Reforming of Methanol

Catalysts ◽

10.3390/catal8090380 ◽

2018 ◽

Vol 8 (9) ◽

pp. 380 ◽

Cited By ~ 9

Author(s):

Pawel Mierczynski ◽

Agnieszka Mierczynska ◽

Radoslaw Ciesielski ◽

Magdalena Mosinska ◽

Magdalena Nowosielska ◽

...

Keyword(s):

Steam Reforming ◽

Photoelectron Spectroscopy ◽

Supported Catalysts ◽

Energy Dispersive Spectrometer ◽

Nickel Catalysts ◽

Impregnation Method ◽

Catalytic Systems ◽

X Ray ◽

Steam Reforming Of Methanol ◽

Temperature Programmed

Herein, we report monometallic Ni and bimetallic Pd–Ni catalysts supported on CeO2–Al2O3 binary oxide which are highly active and selective in oxy-steam reforming of methanol (OSRM). Monometallic and bimetallic supported catalysts were prepared by an impregnation method. The physicochemical properties of the catalytic systems were investigated using a range of methods such as: Brunauer–Emmett–Teller (BET), X-ray Powder Diffraction (XRD), Temperature-programmed reduction (TPR–H2), Temperature-programmed desorption (TPD–NH3), X-ray photoelectron spectroscopy (XPS) and Scanning Electron Microscope equipped with an energy dispersive spectrometer (SEM–EDS). We demonstrate that the addition of palladium facilitates the reduction of nickel catalysts. The activity tests performed for all catalysts confirmed the promotion effect of palladium on the catalytic activity of nickel catalyst and their selectivity towards hydrogen production. Both nickel and bimetallic palladium–nickel supported catalysts showed excellent stability during the reaction. The reported catalytic systems are valuable to make advances in the field of fuel cell technology.

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Mesoporous Ce-doped Ti:Ash Photocatalyst Investigation in Visible Light Photocatalytic Water Pretreatment Process

BULLETIN OF CHEMICAL REACTION ENGINEERING AND CATALYSIS ◽

10.9767/bcrec.15.2.7055.367-378 ◽

2020 ◽

Vol 15 (2) ◽

pp. 367-378

Author(s):

Abdulkarim Abdulrahman Mohamed Suliman ◽

Ruzinah Isha ◽

Mazrul Nizam Abu Seman ◽

Abdul Latif Ahmad ◽

Jamil Roslan

Keyword(s):

Visible Light ◽

Visible Region ◽

Impregnation Method ◽

Wet Impregnation ◽

X Ray ◽

Weight Percentage ◽

Water Pretreatment ◽

Defect Sites ◽

Adsorption Desorption ◽

Wet Impregnation Method

The treatment of organic pollutants in water including semiconductor photocatalysis is a promising approach to disinfect water. The objective of this study is to investigate the effect of Ce loaded on mesoporous Ti:Ash catalyst for water pretreatment process. The mesoporous Ti:Ash catalyst that doped with Ce was synthesized through wet impregnation method with 5%, 10%, and 15% weight percentage of Ce doped on 40:60 Ti:Ash. The photocatalytic properties were characterized through X-ray powder diffraction, scanning electron microscopy with energy-dispersive X-ray spectroscopy, N2 adsorption-desorption studies and diffuse reflectance UV–vis absorption spectroscopy. It is found that the Ti:Ash nanocomposites doped with Ce shifted the light absorption band-edge position to the visible region. Moreover, the Ce doped Ti:Ash has large surface area and pore diameter. The Ce doping could significantly improve the absorption edge of visible light and adjust the cut-off absorption wavelength from 404 nm to 451, 477 and 496 nm for 5%, 10% and 15% Ce-doped mesoporous Ti:Ash catalysts, respectively. As the Ce doping ratio increased, the band gaps decreased from 3.06 eV to 2.53 eV. The most contaminant reduction up to 45% was achieved when Ti:Ash:Ce 40:55:5 was used. Higher Ce loading on the photocatalyst may reduce the photocatalyst performance because supernumerary metal loading on TiO2 can block TiO2 defect sites which are necessary for the adsorption and photoactivation. The OPFA also acts as an adsorbent for some pollutants besides, reducing the water salinity. It can be deduced that the hybrid TiO2 photocatalyst that synthesized with OPFA and doped with Ce has huge potential to treat seawater prior to commercial seawater desalination process. Copyright © 2020 BCREC Group. All rights reserved

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Pd-Only Catalyst Modified by BaO with Co- Precipitation and Impregnation Methods towards the Methanol Fuel Emission Control

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.581-582.313 ◽

2012 ◽

Vol 581-582 ◽

pp. 313-316

Author(s):

Xue Qiao Zhang ◽

Zhi Xiang Ye ◽

Cheng Hua Xu ◽

Ming Zhao ◽

Yao Qiang Chen

Keyword(s):

Co Oxidation ◽

Photoelectron Spectroscopy ◽

Palladium Catalysts ◽

Active Species ◽

Precipitation Method ◽

Impregnation Method ◽

X Ray Diffraction ◽

X Ray ◽

Temperature Programmed ◽

Co Precipitation

Barium oxide was introduced to modify Palladium catalysts supported on CeO2–ZrO2-La2O3-Al2O3 (CZLA) by impregnation and co-precipitation. methods. Various techniques, including X-ray diffraction (XRD), H2-temperature-programmed reduction (H2-TPR) and X-ray photoelectron spectroscopy (XPS), were employed to characterize the physicochemical properties of BaO-modified Pd-only catalyst. Catalytic activity for methanol, CO, C3H8 and NO conversions showed that BaO-modified catalyst prepared by impregnation method exhibited the best performance for methanol, C3H8 and NO removals, while the catalyst prepared by co-precipitation method was in favor of CO oxidation. Combined with the results of XRD, H2-TPR and XPS, it is concluded that the co-existence of PdO and Pd-O-Ce active species by impregnation played an important role in the methanol, C3H8 and NO removals, while the higher dispersion of palladium and improved reducibility were mostly favorable to the CO oxidation. The conversion of NO was co-effected by tow active species and the formation of Ba2AlLaO5 mixed oxide.

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Photocatalytic Reduction of CO2 to Methanol Using the InVO4-Based Photocatalysts

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.396-398.2033 ◽

2011 ◽

Vol 396-398 ◽

pp. 2033-2037 ◽

Cited By ~ 5

Author(s):

Zhi Fang Jia ◽

Fu Min Wang ◽

Ying Bai ◽

Ning Liu

Keyword(s):

Metal Oxides ◽

Diffuse Reflectance Spectroscopy ◽

Photocatalytic Reduction ◽

Impregnation Method ◽

X Ray Diffraction ◽

Electron Hole ◽

Wet Impregnation ◽

X Ray ◽

Reduction Of Co2 ◽

Wet Impregnation Method

The InVO4-based photocatalysts loaded with metal oxides (Fe2O3, CuO, NiO) were synthesized by wet impregnation method. The prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy(SEM), UV-vis diffuse reflectance spectroscopy(DRS). The influence of different metal oxides loading (Fe2O3, CuO, NiO) on the photocatalytic activity for photocatalytic reduction of CO2 was discussed. It is found that Fe2O3-loaded InVO4 significantly enhance the methanol yield through promoting the effective separation of photoinduced electron-hole pairs.

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Catalytic Combustion of Dimethyl Disulfide on Bimetallic Supported Catalysts Prepared by the Wet-Impregnation Method

Catalysts ◽

10.3390/catal9120994 ◽

2019 ◽

Vol 9 (12) ◽

pp. 994 ◽

Cited By ~ 1

Author(s):

Junan Gao ◽

Song Gao ◽

Jun Wei ◽

Hong Zhao ◽

Jie Zhang

Keyword(s):

Synergistic Effect ◽

Catalytic Combustion ◽

Supported Catalysts ◽

Dimethyl Disulfide ◽

Catalytic Performance ◽

Sulfur Poisoning ◽

Impregnation Method ◽

Promoting Effect ◽

Wet Impregnation ◽

Wet Impregnation Method

In this paper, the catalytic combustion of DMDS (dimethyl disulfide, CH3SSCH3) over bimetallic supported catalysts were investigated. It was confirmed that Cu/γ-Al2O3-CeO2 showed best catalytic performance among the five single-metal catalysts. Furthermore, six different metals were separately added into Cu/γ-Al2O3-CeO2 to investigate the promoting effect. The experiments revealed Pt as the most effective promoter and the best catalytic performance was achieved as the adding amount of 0.3 wt%. The characterization results indicated that high activity and resistance to sulfur poisoning of Cu-Pt/γ-Al2O3-CeO2 could be attributed to the synergistic effect between Cu and Pt.

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Ni/x%Nb2O5/Al2O3 Catalysts Prepared via Coprecipitation-Wet Impregnation Method for Methane Steam Reforming

Current Catalysis ◽

10.2174/2211544708666190423130340 ◽

2020 ◽

Vol 9 (1) ◽

pp. 80-89

Author(s):

Juliana F. Gonçalves ◽

Mariana M.V.M. Souza

Keyword(s):

Steam Reforming ◽

Methane Conversion ◽

Coke Formation ◽

Methane Steam Reforming ◽

Impregnation Method ◽

Wet Impregnation ◽

X Ray ◽

Methane Steam ◽

Temperature Programmed ◽

Wet Impregnation Method

Background: Hydrogen has been considered the energy source of the future and one of the processes for its production is the methane steam reforming. The catalyst used industrially is Ni/Al2O3 and the addition of promoter oxides can be an alternative to improve the performance of this catalyst, which suffers from coke formation and sintering. Objective: Evaluate the role of niobia on catalytic activity and stability. Methods: Ni/x%Nb2O5/Al2O3 (x = 5, 10 and 20) catalysts were synthesized via coprecipitation-wet impregnation method and characterized by X-ray fluorescence (XRF), N2 adsorption-desorption, X-ray diffraction (XRD), temperature- programmed reduction (TPR), temperature-programmed desorption of ammonia (TPD-NH3), etc. Finally, the catalysts were tested for methane steam reforming reaction. Results: All niobia-doped catalysts presented similar values of methane conversion and when comparing with Ni-Al, the addition of niobia slightly improved the methane conversion. In the stability test at 800oC, all doped and non-doped catalysts did not deactivate during the 24 h of reaction. Conclusion: The addition of 10 and 20 wt.% of niobia had a significant promoter effect over Ni/Al2O3 catalyst in terms of activity and stability at 800 oC and the sample with 20 wt.% of niobia presented lower coke formation.

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Catalytic Oxidation of CO over Ag-Doped Manganese Oxide Catalysts: Preparation and Catalytic Activity

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1089.133 ◽

2015 ◽

Vol 1089 ◽

pp. 133-136 ◽

Cited By ~ 2

Author(s):

Zhi Dan Fu ◽

Qing Ye ◽

Shui Yuan Cheng ◽

Dao Wang

Keyword(s):

Catalytic Activity ◽

Co Oxidation ◽

Manganese Oxide ◽

Impregnation Method ◽

Efficient Catalyst ◽

Preparation Methods ◽

Wet Impregnation ◽

Adsorption Desorption ◽

Wet Impregnation Method ◽

Incorporation Method

The manganese oxide (MnO2) sample was synthesized by the reaction of KMnO4 with Mn (Ac)2 using the HNO3 solution as pH regulator. The Ag-doped manganese oxide, Ag/MnO2-Q and Ag/MnO2-H, were synthesized by incorporation method and typical wet impregnation method, respectively. The structure of catalysts was characterized by N2 adsorption/desorption and X-ray diffraction. The influences of preparation methods on the catalytic activity of CO oxidation were studied. The doping of Ag to MnO2 decreased the specific surface area of Ag/MnO2 catalysts, especially for Ag/MnO2-H samples prepared by traditional wet-impregnation method. The Ag/MnO2 catalysts showed higher catalytic activity for CO oxidation than that of MnO2. The catalytic activities of Ag/MnO2 samples strongly depended upon the preparing methods, among which 3Ag/MnO2-Q catalyst, prepared by the incorporation method, was the most efficient catalyst towards the addressed reactions. The excellent performance of 3Ag/MnO2-Q was mainly associated with the good low-temperature reducibility, abundant surface oxygen and broadly dispersed silver oxides species.

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Influence of Nature Support on Methane and CO2 Conversion in a Dry Reforming Reaction over Nickel-Supported Catalysts

Materials ◽

10.3390/ma12111777 ◽

2019 ◽

Vol 12 (11) ◽

pp. 1777 ◽

Cited By ~ 2

Author(s):

Anis Hamza Fakeeha ◽

Samsudeen Olajide Kasim ◽

Ahmed Aidid Ibrahim ◽

Ahmed Elhag Abasaeed ◽

Ahmed Sadeq Al-Fatesh

Keyword(s):

Supported Catalysts ◽

Space Velocity ◽

Dry Reforming ◽

Dry Reforming Of Methane ◽

Impregnation Method ◽

X Ray Diffraction ◽

Wet Impregnation ◽

Surface Areas ◽

Diffraction Patterns ◽

Wet Impregnation Method

A promising method to reduce global warming has been methane reforming with CO2, as it combines two greenhouse gases to obtain useful products. In this study, Ni-supported catalysts were synthesized using the wet impregnation method to obtain 5%Ni/Al2O3(SA-5239), 5%Ni/Al2O3(SA-6175), 5%Ni/SiO2, 5%Ni/MCM41, and 5%Ni/SBA15. The catalysts were tested in dry reforming of methane at 700 °C, 1 atm, and a space velocity of 39,000 mL/gcat h, to study the interaction of Ni with the supports, and evaluation was based on CH4 and CO2 conversions. 5%Ni/Al2O3(SA-6175) and 5%Ni/SiO2 gave the highest conversion of CH4 (78 and 75%, respectively) and CO2 (84 and 82%, respectively). The catalysts were characterized by some techniques. Ni phases were identified by X-ray diffraction patterns. Brunauer–Emmett–Teller analysis showed different surface areas of the catalysts with the least being 4 m2/g and the highest 668 m2/g belonging to 5%Ni/Al2O3(SA-5239) and 5%Ni/SBA15, respectively. The reduction profiles revealed weak NiO-supports interaction for 5%Ni/Al2O3(SA-5239), 5%Ni/MCM41, and 5%Ni/SBA15; while strong interaction was observed in 5%Ni/Al2O3(SA-6175) and 5%Ni/SiO2. The 5%Ni/Al2O3(SA-6175) and 5%Ni/SiO2 were close with respect to performance; however, the former had a higher amount of carbon deposit, which is mostly graphitic, according to the conducted thermal analysis. Carbon deposits on 5%Ni/SiO2 were mainly atomic in nature.

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