Nitrate Combustion Methods to Prepare Highly Active Cu/ZnO Catalysts for Low-Temperature Methanol Synthesis: Comparative Behaviors of Citric Acid in Air or Argon Atmosphere

2013 ◽  
Vol 86 (10) ◽  
pp. 1202-1209
Author(s):  
Chunyang Zeng ◽  
Lei Shi ◽  
Jian Sun ◽  
Yoshiharu Yoneyama ◽  
Tiejun Wang ◽  
...  
Keyword(s):  
Citric Acid ◽  
Low Temperature ◽  
Methanol Synthesis ◽  
Argon Atmosphere ◽  
Highly Active

Pt-Pd Nanoalloy for the Unprecedented Activation of Carbon-Fluorine Bond at Low Temperature

2019 ◽  
Author(s):  
Raghu Nath Dhital ◽  
keigo nomura ◽  
Yoshinori Sato ◽  
Setsiri Haesuwannakij ◽  
Masahiro Ehara ◽  
...  
Keyword(s):  
Activation Energy ◽  
Low Temperature ◽  
Dft Calculations ◽  
Bond Activation ◽  
Mild Conditions ◽  
Selective Transformation ◽  
Rate Determining Step ◽  
Highly Active ◽  
Harsh Conditions ◽  
Reaction Profile

Carbon-Fluorine (C-F) bonds are considered the most inert organic functionality and their selective transformation under mild conditions remains challenging. Herein, we report a highly active Pt-Pd nanoalloy as a robust catalyst for the transformation of C-F bonds into C-H bonds at low temperature, a reaction that often required harsh conditions. The alloying of Pt with Pd is crucial to activate C-F bond. The reaction profile kinetics revealed that the major source of hydrogen in the defluorinated product is the alcoholic proton of 2-propanol, and the rate-determining step is the reduction of the metal upon transfer of the <i>beta</i>-H from 2-propanol. DFT calculations elucidated that the key step is the selective oxidative addition of the O-H bond of 2-propanol to a Pd center prior to C-F bond activation at a Pt site, which crucially reduces the activation energy of the C-F bond. Therefore, both Pt and Pd work independently but synergistically to promote the overall reaction

Highly active PdCeOx composite catalysts for low-temperature CO oxidation, prepared by plasma-arc synthesis

2014 ◽  
Vol 147 ◽  
pp. 132-143 ◽  
Author(s):  
R.V. Gulyaev ◽  
E.M. Slavinskaya ◽  
S.A. Novopashin ◽  
D.V. Smovzh ◽  
A.V. Zaikovskii ◽  
...  
Keyword(s):  
Low Temperature ◽  
Co Oxidation ◽  
Plasma Arc ◽  
Composite Catalysts ◽  
Highly Active ◽  
Low Temperature Co Oxidation

scholarly journals Structural and kinetical studies on the supercritical CO2 dried Cu/ZnO catalyst for low-temperature methanol synthesis

2016 ◽  
Vol 295 ◽  
pp. 160-166 ◽  
Author(s):  
Fanzhi Meng ◽  
Qingde Zhang ◽  
Guohui Yang ◽  
Ruiqin Yang ◽  
Yoshiharu Yoneyama ◽  
...  
Keyword(s):  
Low Temperature ◽  
Methanol Synthesis ◽  
Supercritical Co2

Effect of modifiers on the performance of Cu-ZnO-based catalysts for low-temperature methanol synthesis

2014 ◽  
Vol 42 (6) ◽  
pp. 704-709 ◽  
Author(s):  
Xiao-bo TANG ◽  
Tsubaki NORITATSU ◽  
Hong-juan XIE ◽  
Yi-zhuo HAN ◽  
Yi-sheng TAN
Keyword(s):  
Low Temperature ◽  
Methanol Synthesis

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 Highly Active Catalysts Based on the Rh4(CO)12 Cluster Supported on Ce0.5Zr0.5 and Zr Oxides for Low-Temperature Methane Steam Reforming

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 800 ◽  
Author(s):  
Andrea Fasolini ◽  
Silvia Ruggieri ◽  
Cristina Femoni ◽  
Francesco Basile
Keyword(s):  
Low Temperature ◽  
Steam Reforming ◽  
Supported Catalysts ◽  
Supported Catalyst ◽  
Methane Steam Reforming ◽  
Small Scale ◽  
Methane Reforming ◽  
Hydrogen Purification ◽  
Highly Active ◽  
Reforming Reactions

Syngas and Hydrogen productions from methane are industrially carried out at high temperatures (900 °C). Nevertheless, low-temperature steam reforming can be an alternative for small-scale plants. In these conditions, the process can also be coupled with systems that increase the overall efficiency such as hydrogen purification with membranes, microreactors or enhanced reforming with CO2 capture. However, at low temperature, in order to get conversion values close to the equilibrium ones, very active catalysts are needed. For this purpose, the Rh4(CO)12 cluster was synthetized and deposited over Ce0.5Zr0.5O2 and ZrO2 supports, prepared by microemulsion, and tested in low-temperature steam methane reforming reactions under different conditions. The catalysts were active at 750 °C at low Rh loadings (0.05%) and outperformed an analogous Rh-impregnated catalyst. At higher Rh concentrations (0.6%), the Rh cluster deposited on Ce0.5Zr0.5 oxide reached conversions close to the equilibrium values and good stability over long reaction time, demonstrating that active phases derived from Rh carbonyl clusters can be used to catalyze steam reforming reactions. Conversely, the same catalyst suffered from a fast deactivation at 500 °C, likely related to the oxidation of the Rh phase due to the oxygen-mobility properties of Ce. Indeed, at 500 °C the Rh-based ZrO2-supported catalyst was able to provide stable results with higher conversions. The effects of different pretreatments were also investigated: at 500 °C, the catalysts subjected to thermal treatment, both under N2 and H2, proved to be more active than those without the H2 treatment. In general, this work highlights the possibility of using Rh carbonyl-cluster-derived supported catalysts in methane reforming reactions and, at low temperature, it showed deactivation phenomena related to the presence of reducible supports.

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