Gold Catalyst Anchored to Pre-Reduced Co3O4 Nanorods for the Hydrodeoxygenation of Vanillin Using Alcohols as Hydrogen Donors

2022 ◽  
Author(s):  
Qingliang Liao ◽  
Meng Shi ◽  
Qingxiao Zhang ◽  
Weihua Cheng ◽  
Peiyi Ji ◽  
...  
Keyword(s):  
Gold Catalyst ◽  
Hydrogen Donors ◽  
Co3o4 Nanorods

Electron Holographic Nano-Characterization of Gold Catalyst at Interface

2002 ◽  
Vol 727 ◽  
Author(s):  
S. Ichikawa ◽  
T. Akita ◽  
M. Okumura ◽  
M. Haruta ◽  
K. Tanaka
Keyword(s):  
Contact Angle ◽  
Titanium Oxide ◽  
Gold Catalyst ◽  
Three Dimensional ◽  
High Resolution Electron Microscopy ◽  
Electron Holography ◽  
Gold Particles ◽  
Oxide Support ◽  
The Mean ◽  
A Charge

AbstractThe catalytic properties of nanostructured gold catalyst are known to depend on the size of the gold particles and to be activated when the size decreases to a few nanometers. We investigated the size dependence of the three-dimensional nanostructure on the mean inner potential of gold catalysts supported on titanium oxide using electron holography and high-resolution electron microscopy (HREM). The contact angle of the gold particles on the titanium oxide tended to be over 90° for gold particles with a size of over 5 nm, and below 90° for a size of below 2 nm. This decreasing change in the contact angle (morphology) acts to increase the perimeter and hence the area of the interface between the gold and titanium oxide support, which is considered to be an active site for CO oxidation. The mean inner potential of the gold particles also changed as their size decreased. The value of the inner potential of gold, which is approximately 25 V in bulk state, rose to over 40 V when the size of the gold particles was less than 2 nm. This phenomenon indicates the existence of a charge transfer at the interface between gold and titanium oxide. The 3-D structure change and the inner potential change should be attributed to the specific electronic structure at the interface, owing to both the “nano size effect” and the “hetero-interface effect.”

scholarly journals Catalytic Activity of Beta-Cyclodextrin-Gold Nanoparticles Network in Hydrogen Evolution Reaction

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 118
Author(s):  
Qui Quach ◽  
Erik Biehler ◽  
Ahmed Elzamzami ◽  
Clay Huff ◽  
Julia M. Long ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Gold Catalyst ◽  
Hydrogen Gas ◽  
Hydrolysis Reaction ◽  
X Ray Diffraction ◽  
Beta Cyclodextrin ◽  
Transmission Electron ◽  
Production Of Hydrogen ◽  
Climate Crisis

The current climate crisis warrants investigation into alternative fuel sources. The hydrolysis reaction of an aqueous hydride precursor, and the subsequent production of hydrogen gas, prove to be a viable option. A network of beta-cyclodextrin capped gold nanoparticles (BCD-AuNP) was synthesized and subsequently characterized by Powder X-Ray Diffraction (P-XRD), Fourier Transform Infrared (FTIR), Transmission Electron Microscopy (TEM), and Ultraviolet-Visible Spectroscopy (UV-VIS) to confirm the presence of gold nanoparticles as well as their size of approximately 8 nm. The catalytic activity of the nanoparticles was tested in the hydrolysis reaction of sodium borohydride. The gold catalyst performed best at 303 K producing 1.377 mL min−1 mLcat−1 of hydrogen. The activation energy of the catalyst was calculated to be 54.7 kJ/mol. The catalyst resisted degradation in reusability trials, continuing to produce hydrogen gas in up to five trials.

scholarly journals Hydrogen-Free Deoxygenation of Bio-Oil Model Compounds over Sulfur-Free Polymer Supported Catalysts

2020 ◽  
Vol 7 (1) ◽  
pp. 29-36
Author(s):  
Antonina A. Stepacheva ◽  
Mariia E. Markova ◽  
Yury V. Lugovoy ◽  
Kirill V. Chalov ◽  
Mikhail G. Sulman ◽  
...  
Keyword(s):  
Supercritical Fluids ◽  
Aromatic Compounds ◽  
Supported Catalysts ◽  
Major Product ◽  
Hypercrosslinked Polystyrene ◽  
Model Compounds ◽  
Transportation Fuel ◽  
Novel Approach ◽  
Bio Oil ◽  
Hydrogen Donors

AbstractHydrotreatment of bio-oil oxygen compounds allows the final product to be effectively used as a liquid transportation fuel from biomass. Deoxygenation is considered to be one of the most promising ways for bio-oil upgrading. In the current work, we describe a novel approach for the deoxygenation of bio-oil model compounds (anisole, guaiacol) using supercritical fluids as both the solvent and hydrogen-donors. We estimated the possibility of the use of complex solvent consisting of non-polar n-hexane with low critical points (Tc = 234.5 ºC, Pc = 3.02 MPa) and propanol-2 used as H-donor. The experiments were performed without catalysts and in the presence of noble and transition metals hydrothermally deposited on the polymeric matrix of hypercrosslinked polystyrene (HPS). The experiments showed that the presence of 20 vol. % of propanol-2 in n-hexane results in the highest (up to 99%) conversion of model compounds. When the process was carried out without a catalyst, phenols were found to be a major product yielding up to 95 %. The use of Pd- and Co-containing catalyst yielded 90 % of aromatic compounds (benzene and toluene) while in the presence of Ru and Ni cyclohexane and methylcyclohexane (up to 98 %) were the main products.

High activity and regenerability of a palladium-gold catalyst for chloroform degradation

2015 ◽  
Vol 91 (10) ◽  
pp. 2590-2596 ◽  
Author(s):  
Juan C Velázquez ◽  
Sukit Leekumjorn ◽  
Gary D Hopkins ◽  
Kimberly N Heck ◽  
Jason S McPherson ◽  
...  
Keyword(s):  
High Activity ◽  
Gold Catalyst

2-Aryl-1,3-dimethylbenzimidazolines as Effective Electron and Hydrogen Donors in Photoinduced Electron-Transfer Reactions

2015 ◽  
Vol 68 (11) ◽  
pp. 1640 ◽  
Author(s):  
Eietsu Hasegawa ◽  
Shin-ya Takizawa
Keyword(s):  
Electron Transfer ◽  
Hydrogen Atom ◽  
Photoinduced Electron Transfer ◽  
Hydrogen Atom Transfer ◽  
Transfer Reactions ◽  
Organic Substrates ◽  
Iridium Complexes ◽  
Effective Electron ◽  
Hydrogen Donors ◽  
Wavelength Light

2-Aryl-1,3-dimethylbenzimidazolines (DMBIHs) have been applied to photoinduced electron-transfer reductions of various organic substrates. Either direct or indirect electron transfer between the substrates and DMBIHs is utilized to promote the desired transformations. Photoexcitation of the substrates using light above 280 nm was carried out in the former protocol whereas a photosensitization method using materials such as substituted pyrenes, ruthenium and iridium complexes that absorb longer-wavelength light was employed in the latter. In these reactions, DMBIHs undergo initial electron transfer and subsequent proton or hydrogen atom transfer.

Porous cobalt oxide (Co3O4) nanorods: Facile syntheses, optical property and application in lithium-ion batteries

2009 ◽  
Vol 182 (11) ◽  
pp. 3177-3182 ◽  
Author(s):  
Rui Xu ◽  
Jiawei Wang ◽  
Qiuyu Li ◽  
Guoying Sun ◽  
Enbo Wang ◽  
...  
Keyword(s):  
Optical Property ◽  
Lithium Ion Batteries ◽  
Cobalt Oxide ◽  
Lithium Ion ◽  
Co3o4 Nanorods

Graphitic Carbon Nitride Composites with MoO3-Decorated Co3O4 Nanorods as Catalysts for Oxygen and Hydrogen Evolution

2021 ◽  
Author(s):  
Imtiaz Ahmed ◽  
Rathindranath Biswas ◽  
Ranjit A. Patil ◽  
Krishna Kamal Halder ◽  
Harjinder Singh ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Carbon Nitride ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Co3o4 Nanorods
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