Local structures and TWC activity of Pd supported on Ni-substituted aluminium oxide borates

2016 ◽  
Vol 6 (14) ◽  
pp. 5464-5472 ◽  
Author(s):  
Yuki Nagao ◽  
Takafumi Hamada ◽  
Ayaka Imamura ◽  
Satoshi Hinokuma ◽  
Yunosuke Nakahara ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Aluminum Oxide ◽  
Aluminium Oxide ◽  
Pd Catalyst ◽  
No Adsorption ◽  
Local Structures ◽  
Three Way Catalysis

The Pd catalyst supported on Ni-substituted aluminum oxide borate (Ni–10A2B) achieved the highest catalytic activity under three-way catalysis conditions, where NO adsorption onto the Ni site promoted the reaction with hydrogen spilt over from Pd under rich conditions.

scholarly journals Synthesis, Characterization of Chitosan-Aluminum Oxide Nanocomposite for Green Synthesis of Annulated Imidazopyrazol Thione Derivatives

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1160
Author(s):  
Abir S. Abdel-Naby ◽  
Sara Nabil ◽  
Sarah Aldulaijan ◽  
Ibtisam M. Ababutain ◽  
Azzah I. Alghamdi ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Aluminum Oxide ◽  
Reaction Medium ◽  
Thiol Group ◽  
Docking Studies ◽  
Significant Loss ◽  
Gram Negative Bacteria ◽  
Organic Catalyst ◽  
Group 1

Chitosan-aluminum oxide nanocomposite was synthesized, characterized, and used as a green heterogeneous catalyst to synthesize novel imidazopyrazolylthione derivatives. Nanocomposite polymeric material was characterized by EDS-SEM and XRD. The powerful catalytic activity, and its base character of the nanocomposite, was used to synthesize imidazopyrazolylthione (1) in a good yield compared to traditional cyclocondensation synthesis. Using the nanocomposite catalyst, substitution of the thiol group (1) afforded the corresponding thiourea (2) and the corresponding ester (3). The efficiency of the nanocomposite over the traditional base organic catalyst, Et3N and NaOH, makes it an effective, economic, and reproducible nontoxic catalyst. Moreover, the heterogeneous nanocomposite polymeric film was easily isolated from the reaction medium, and recycled up to four times, without a significant loss of its catalytic activity. The newly synthesized derivatives were screened as antibacterial agents and showed high potency. Molecular docking was also performed for a more in-depth investigation. The results of the docking studies have demonstrated that the docked compounds have strong interaction energies with both Gram-positive and Gram-negative bacteria.

scholarly journals MODIFIED COBALT CATALYSTS FOR HYDROGENATION OF HYDROCARBONS

2020 ◽  
Vol 18 (3) ◽  
pp. 156-161
Author(s):  
A.N. Aitugan ◽  
S.K. Tanirbergenova ◽  
Ye. Tileuberdi ◽  
D. Tugelbayeva
Keyword(s):  
Catalytic Activity ◽  
Aluminum Oxide ◽  
Process Parameters ◽  
Cobalt Catalyst ◽  
Cobalt Catalysts ◽  
Oxide Content ◽  
Acetylene Hydrogenation ◽  
Aluminum Oxides ◽  
Selective Hydrogenation Of Acetylene ◽  
Chemical Contents

This work is devoted to the study of the influence of aluminum oxide content on the activity of cobalt catalysts in the reaction of selective hydrogenation of acetylene to ethylene. Cobalt catalysts modified with aluminum oxide having size between 50 to 500 nm were synthesized. Chemical contents and structure of carrier were investigated.  The catalytic activity of 5 % Со /clay and 5% Co/SiAl catalysts at acetylene hydrogenation was studied in the temperature range 100-180 , with a ratio of 1:2 of acetylene and hydrogen. The ethylene yield is 87.8 % in modifying the cobalt catalyst with aluminum oxide, whereas with the same process parameters, the ethylene yield is 72 %. 5 % Cobalt catalysts modified with 1.5 % aluminum oxides are more active in hydrogenation acetylene process than 5 % Со /clay 450 ℃ catalyst.

scholarly journals Electrical Promotion-Assisted Automotive Exhaust Catalyst: Highly Active and Selective NO Reduction to N2 at Low-Temperatures

2021 ◽  
Author(s):  
Yuki Omori ◽  
Ayaka Shigemoto ◽  
Kohei Sugihara ◽  
Takuma Higo ◽  
Toru Uenishi ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Low Temperature ◽  
Electric Field ◽  
Low Temperatures ◽  
No Reduction ◽  
Lattice Oxygen ◽  
Pd Catalyst ◽  
Highly Active ◽  
Automotive Exhaust Catalyst ◽  
Activated Surface

Pd catalyst (Pd/Ce<sub>0.7</sub>Zr<sub>0.3</sub>O<sub>2</sub>) in an electric field exhibits extremely high three-way catalytic activity (TWC: NO-C<sub>3</sub>H<sub>6</sub>-CO-O<sub>2</sub>-H<sub>2</sub>O). By applying an electric field to the semiconductor catalyst, low-temperature operation of TWC can be achieved even at 473 K by virtue of the activated surface-lattice oxygen.

scholarly journals Copper-Containing Mixed Metal Oxides (Al, Fe, Mn) for Application in Three-Way Catalysis

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1344
Author(s):  
Tim Van Everbroeck ◽  
Radu-George Ciocarlan ◽  
Wouter Van Hoey ◽  
Myrjam Mertens ◽  
Pegie Cool
Keyword(s):  
Catalytic Activity ◽  
Spinel Structure ◽  
Mixed Oxides ◽  
High Catalytic Activity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Application ◽  
Mixed Spinel ◽  
Co Precipitation ◽  
Three Way Catalysis

Mixed oxides were synthesized by co-precipitation of a Cu source in combination with Al, Fe or Mn corresponding salts as precursors. The materials were calcined at 600 and 1000 °C in order to crystallize the phases and to mimic the reaction conditions of the catalytic application. At 600 °C a mixed spinel structure was only formed for the combination of Cu and Mn, while at 1000 °C all the materials showed mixed spinel formation. The catalysts were applied in three-way catalysis using a reactor with a gas mixture containing CO, NO and O2. All the materials calcined at 600 °C displayed the remarkable ability to oxidize CO with O2 but also to reduce NO with CO, while the pure oxides such as CuO and MnO2 were not able to. The high catalytic activity at 600 °C was attributed to small supported CuO particles present and imperfections in the spinel structure. Calcination at 1000 °C crystallized the structure further which led to a dramatic loss in catalytic activity, although CuAl2O4 and CuFe2O4 still converted some NO. The materials were characterized by X-ray diffraction (XRD), Raman spectroscopy, H2-Temperatrue Programmed Reduction (H2-TPR), N2-sorption and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX).

scholarly journals Catalytic Hydrodechlorination of Chlorophenols in a Continuous Flow Pd/CNT-Ni Foam Micro Reactor Using Formic Acid as a Hydrogen Source

Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 77 ◽  
Author(s):  
Jun Xiong ◽  
Ying Ma
Keyword(s):  
Catalytic Activity ◽  
Formic Acid ◽  
Continuous Flow ◽  
Catalyst Surface ◽  
Reactor System ◽  
Packed Bed Reactor ◽  
Pd Catalyst ◽  
Ni Foam ◽  
Catalytic Hydrodechlorination ◽  
Micro Reactor

Catalytic hydrodechlorination (HDC) has been considered as a promising method for the treatment of wastewater containing chlorinated organic pollutants. A continuous flow Pd/carbon nanotube (CNT)-Ni foam micro reactor system was first developed for the rapid and highly efficient HDC with formic acid (FA) as a hydrogen source. This micro reactor system, exhibiting a higher catalytic activity of HDC than the conventional packed bed reactor, reduced the residence time and formic acid consumption significantly. The desired outcomes (dichlorination >99.9%, 4-chlorophenol outlet concentration <0.1 mg/L) can be obtained under a very low FA/substrate molar ratio (5:1) and short reaction cycle (3 min). Field emission scanning electron microcopy (FESEM) and deactivation experiment results indicated that the accumulation of phenol (the main product during the HDC of chlorophenols) on the Pd catalyst surface can be the main factor for the long-term deactivation of the Pd/CNT-Ni foam micro reactor. The catalytic activity deactivation of the micro reactor could be almost completely regenerated by the efficient removal of the absorbed phenol from the Pd catalyst surface.

Tribocatalytic Enhancement of Methane Oxidation

2005 ◽  
Author(s):  
Tomotaka Abe ◽  
Ken’ichi Hiratsuka ◽  
Czesław Kajdas
Keyword(s):  
Organic Chemistry ◽  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Aluminum Oxide ◽  
Electron Emission ◽  
Oxidation Reaction ◽  
Negative Ion ◽  
Silver Catalyst ◽  
Oxidation Reactions ◽  
Action Mechanism

Oxidation reaction of methane is one of the most fundamental reactions in organic chemistry. This reaction is enhanced by silver catalyst [1]. In this study, we confirmed that the catalytic activity of silver is enhanced more by the friction. This effect is called tribocatalysis. In previous studies about tribocatalysis, we have shown that the oxidation reactions of hydrogen [2], carbon monoxide [3] and ethylene were promoted by the friction. According to NIRAM (negative-ion-radical action mechanism) approach, exo-electron emission triggers the promotion of chemical reactions [4]. Insulator such as aluminum oxide, when it is worn, emits larger number of negative particles including electrons compared with metals [5]. Therefore we expected that the friction of aluminum oxide promotes tribochemical reactions more than metals.

scholarly journals Synthesis, catalytic activity, and leaching studies of a heterogeneous Pd-catalyst including an immobilized bis(oxazoline) ligand

2012 ◽  
Vol 286 ◽  
pp. 30-40 ◽  
Author(s):  
H. Gruber-Woelfler ◽  
P.F. Radaschitz ◽  
P.W. Feenstra ◽  
W. Haas ◽  
J.G. Khinast
Keyword(s):  
Catalytic Activity ◽  
Pd Catalyst
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