Perfluoro-tagged rhodium and ruthenium nanoparticles immobilized on silica gel as highly active catalysts for hydrogenation of arenes under mild conditions

2013 ◽  
Vol 37 (2) ◽  
pp. 278-282 ◽  
Author(s):  
Sandra Niembro ◽  
Silvia Donnici ◽  
Alexandr Shafir ◽  
Adelina Vallribera ◽  
María L. Buil ◽  
...  
Keyword(s):  
Silica Gel ◽  
Ruthenium Nanoparticles ◽  
Mild Conditions ◽  
Highly Active

Cellulose nanocrystals as non-innocent supports for the synthesis of ruthenium nanoparticles and their application to arene hydrogenation

RSC Advances ◽  
2015 ◽  
Vol 5 (66) ◽  
pp. 53207-53210 ◽  
Author(s):  
Madhu Kaushik ◽  
Hava Meira Friedman ◽  
Mary Bateman ◽  
Audrey Moores
Keyword(s):  
Cellulose Nanocrystals ◽  
Ruthenium Nanoparticles ◽  
Hydrogenation Catalysts ◽  
Mild Conditions ◽  
Ru Nanoparticles ◽  
Highly Active ◽  
Arene Hydrogenation

Ru nanoparticles deposited onto cellulose nanocrystals are highly active arene hydrogenation catalysts under mild conditions.

scholarly journals Conversion of Polyolefin Waste to Liquid Alkanes with Ru-Based Catalysts under Mild Conditions

2020 ◽  
Author(s):  
Julie E. Rorrer ◽  
Gregg T. Beckham ◽  
Yuriy Román-Leshkov
Keyword(s):  
Plastic Waste ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Optimal Conditions ◽  
Ruthenium Nanoparticles ◽  
Active Materials ◽  
Mild Conditions ◽  
Highly Active ◽  
Liquid Alkanes ◽  
Long Chain

<p>Chemical upcycling of waste polyolefins via hydrogenolysis offers unique opportunities for selective depolymerization compared to high temperature thermal deconstruction. Here, we demonstrate the hydrogenolysis of polyethylene into liquid alkanes under mild conditions using ruthenium nanoparticles sup-ported on carbon (Ru/C). Reactivity studies on a model <i>n</i>-octadecane substrate showed that Ru/C catalysts are highly active and se-lective for the hydrogenolysis of C(sp<sup>3</sup>)-C(sp<sup>3</sup>) bonds at temperatures ranging from 200-250°C. Under optimal conditions of 200°C in 20 bar H2, polyethylene (average Mw ~4,000) was converted into liquid <i>n</i>-alkanes with yields of up to 45% by mass after 16 h using a 5 wt% Ru/C catalyst, with the remaining products comprising light alkane gases (C1-C6). At 250°C, nearly stoichiometric yields of CH4 were obtained from polyethylene over the catalyst. The hy-drogenolysis of long chain, low-density polyethylene (LDPE) and a post-consumer LDPE plastic bottle to produce C7-C45 alkanes was also achieved over Ru/C, demonstrating the feasibility of this reac-tion for the valorization of realistic post-consumer plastic waste. By identifying Ru-based catalysts as a class of active materials for the hydrogenolysis of polyethene, this study opens new avenues for the valorization of plastic waste under mild conditions.<br></p>

scholarly journals Conversion of Polyolefin Waste to Liquid Alkanes with Ru-Based Catalysts under Mild Conditions

2020 ◽  
Author(s):  
Julie E. Rorrer ◽  
Gregg T. Beckham ◽  
Yuriy Román-Leshkov
Keyword(s):  
Plastic Waste ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Optimal Conditions ◽  
Ruthenium Nanoparticles ◽  
Active Materials ◽  
Mild Conditions ◽  
Highly Active ◽  
Liquid Alkanes ◽  
Long Chain

<p>Chemical upcycling of waste polyolefins via hydrogenolysis offers unique opportunities for selective depolymerization compared to high temperature thermal deconstruction. Here, we demonstrate the hydrogenolysis of polyethylene into liquid alkanes under mild conditions using ruthenium nanoparticles sup-ported on carbon (Ru/C). Reactivity studies on a model <i>n</i>-octadecane substrate showed that Ru/C catalysts are highly active and se-lective for the hydrogenolysis of C(sp<sup>3</sup>)-C(sp<sup>3</sup>) bonds at temperatures ranging from 200-250°C. Under optimal conditions of 200°C in 20 bar H2, polyethylene (average Mw ~4,000) was converted into liquid <i>n</i>-alkanes with yields of up to 45% by mass after 16 h using a 5 wt% Ru/C catalyst, with the remaining products comprising light alkane gases (C1-C6). At 250°C, nearly stoichiometric yields of CH4 were obtained from polyethylene over the catalyst. The hy-drogenolysis of long chain, low-density polyethylene (LDPE) and a post-consumer LDPE plastic bottle to produce C7-C45 alkanes was also achieved over Ru/C, demonstrating the feasibility of this reac-tion for the valorization of realistic post-consumer plastic waste. By identifying Ru-based catalysts as a class of active materials for the hydrogenolysis of polyethene, this study opens new avenues for the valorization of plastic waste under mild conditions.<br></p>

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

Electron Donation by Low-Crystalline Ba-La-Ce Oxygen-Deficient Composite Oxide Accumulating on Ru Nanoparticles for Ammonia Synthesis under Mild Conditions

2019 ◽  
Author(s):  
Katsutoshi Sato ◽  
Shin-ichiro Miyahara ◽  
Yuta Ogura ◽  
Kotoko Tsujimaru ◽  
Yuichiro Wada ◽  
...  
Keyword(s):  
Ammonia Synthesis ◽  
Bond Cleavage ◽  
Synthesis Process ◽  
Strong Electron ◽  
Mild Conditions ◽  
Ru Nanoparticles ◽  
Rate Determining Step ◽  
Highly Active ◽  
Composite Oxides ◽  
Low Crystalline

<p>To mitigate global problems related to energy and global warming, it is helpful to develop an ammonia synthesis process using catalysts that are highly active under mild conditions. Here we show that the ammonia synthesis activity of Ru/Ba/LaCeO<i><sub>x</sub></i> pre-reduced at 700 °C is the highest reported among oxide-supported Ru catalysts. Our results indicate that low crystalline oxygen-deficient composite oxides, which include Ba<sup>2+</sup>, Ce<sup>3+</sup> and La<sup>3+</sup>, with strong electron-donating ability, accumulate on Ru particles and thus promote N≡N bond cleavage, which is the rate determining step for ammonia synthesis.</p>

Electron Donation by Low-Crystalline Ba-La-Ce Oxygen-Deficient Composite Oxide Accumulating on Ru Nanoparticles for Ammonia Synthesis under Mild Conditions

2019 ◽  
Author(s):  
Katsutoshi Sato ◽  
Shin-ichiro Miyahara ◽  
Yuta Ogura ◽  
Kotoko Tsujimaru ◽  
Yuichiro Wada ◽  
...  
Keyword(s):  
Ammonia Synthesis ◽  
Bond Cleavage ◽  
Synthesis Process ◽  
Strong Electron ◽  
Mild Conditions ◽  
Ru Nanoparticles ◽  
Rate Determining Step ◽  
Highly Active ◽  
Composite Oxides ◽  
Low Crystalline

<p>To mitigate global problems related to energy and global warming, it is helpful to develop an ammonia synthesis process using catalysts that are highly active under mild conditions. Here we show that the ammonia synthesis activity of Ru/Ba/LaCeO<i><sub>x</sub></i> pre-reduced at 700 °C is the highest reported among oxide-supported Ru catalysts. Our results indicate that low crystalline oxygen-deficient composite oxides, which include Ba<sup>2+</sup>, Ce<sup>3+</sup> and La<sup>3+</sup>, with strong electron-donating ability, accumulate on Ru particles and thus promote N≡N bond cleavage, which is the rate determining step for ammonia synthesis.</p>

scholarly journals Silica Gel-Induced Aryne Generation from o-Triazenylarylboronic Acids as Stable Solid Precursors

2021 ◽  
Author(s):  
Motoki Ito ◽  
Yuka Yamabayashi ◽  
Mio Oikawa ◽  
Emi Kano ◽  
Kazuhiro Higuchi ◽  
...  
Keyword(s):  
Silica Gel ◽  
Mild Conditions ◽  
Shelf Stable

We report the development of o-triazenylarylboronic acids as shelf-stable solid aryne precursors, which generate (hetero)arynes under remarkably mild conditions using silica gel as the sole reagent and undergo reactions with...

A new approach to arylhydrazides via the reaction of the Mitsunobu reagent with arynes: further application to access diverse nitrogen-containing heterocycles in one pot

2017 ◽  
Vol 4 (8) ◽  
pp. 1636-1639 ◽  
Author(s):  
Bin Cheng ◽  
Bian Bao ◽  
Yanhe Chen ◽  
Ning Wang ◽  
Yun Li ◽  
...  
Keyword(s):  
One Pot ◽  
New Approach ◽  
Mild Conditions ◽  
Highly Active ◽  
Active Intermediates

A new route to arylhydrazides involving the reaction of two highly active intermediates, the 1,3-zwitterion generated in situ from the Mitsunobu reagent and arynes, under mild conditions has been developed.

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