Clean protocol for deoxygenation of epoxides to alkenes via catalytic hydrogenation using gold

2021 ◽  
Author(s):  
Jhonatan L. Fiorio ◽  
Liane M. Rossi
Keyword(s):  
Catalytic Hydrogenation ◽  
Au Nps ◽  
Selective Deoxygenation

Au NP catalyst combined with triethylphosphite, P(OEt)3, is remarkably more reactive than solely Au NPs for the selective deoxygenation of epoxides to alkenes.

scholarly journals Porous Wood Decorated with Gold Nanoparticles as Flow-through Membrane Reactor for Catalytic Hydrogenation of Methylene Blue and 4-Nitrophenol

2021 ◽  
Author(s):  
Yuanyuan Yu ◽  
Qingtong Zhang ◽  
Mingchao Chi ◽  
Hongrui Jiang ◽  
Xi Liu ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Catalytic Hydrogenation ◽  
Organic Contaminants ◽  
Low Cost ◽  
Three Dimensional ◽  
Wood Chip ◽  
Flow Process ◽  
Au Nps

Abstract In this study, gold nanoparticles (Au NPs) were decorated into Paulownia Sieb. et Zucc. chip. Lignin, as one main component of wood, contains the reducing groups e.g. hydroxyl, carbonyl and aldehyde groups. Under sunlight irradiation, Au (III) diffused into wood was in situ reduced by lignin to form gold nanoparticles. Therefore, the Au NPs/Wood was successfully fabricated by this facile and green procedure. Meanwhile, the three-dimensional interpenetrating network of wood prevented the aggregation of Au NPs which retained its catalytic activity. Methylene blue and 4-nitrophenol were adopted as model organic contaminants to evaluate the catalytic hydrogenation ability of the Au NPs/Wood. The analyses of XRD, SEM, ICP-MS and XPS indicated that Au NPs were successfully immobilized in wood chip. The degradation results revealed that the Au NPs/Wood has excellent catalytic activity for methylene blue and 4-nitrophenol hydrogenation under batchwise and continuous flow process. Meanwhile, the Au NPs/Wood also exhibited excellent recyclability. The hydrogenation efficiency of MB and 4-NP still reaches more than 90% after 8 cycles. This study provides a new solution for green and low-cost fabrication of Au NPs/Wood which has broad application prospects in wastewater treatment.

Nanometer Scale Spectroscopic Visualization of Catalytic Sites During a Hydrogenation Reaction on a Pd/Au Bimetallic Catalyst

2020 ◽  
Author(s):  
hao yin ◽  
Liqing Zheng ◽  
Wei Fang ◽  
Yin-Hung Lai ◽  
Nikolaus Porenta ◽  
...  
Keyword(s):  
Catalytic Hydrogenation ◽  
Density Functional ◽  
Hydrogen Transfer ◽  
Bimetallic Catalyst ◽  
Local Environment ◽  
Hydrogenation Reaction ◽  
Boundary Density ◽  
Catalytic Sites ◽  
Powerful Analytical Tool ◽  
Tip Enhanced Raman Spectroscopy

<p>Understanding the mechanism of catalytic hydrogenation at the local environment requires chemical and topographic information involving catalytic sites, active hydrogen species and their spatial distribution. Here, tip-enhanced Raman spectroscopy (TERS) was employed to study the catalytic hydrogenation of chloro-nitrobenzenethiol on a well-defined Pd(sub-monolayer)/Au(111) bimetallic catalyst (<i>p</i><sub>H2</sub>=1.5 bar, 298 K), where the surface topography and chemical fingerprint information were simultaneously mapped with nanoscale resolution (≈10 nm). TERS imaging of the surface after catalytic hydrogenation confirms that the reaction occurs beyond the location of Pd sites. The results demonstrate that hydrogen spillover accelerates hydrogenation at the Au sites within 20 nm from the bimetallic Pd/Au boundary. Density functional theory was used to elucidate the thermodynamics of interfacial hydrogen transfer. We demonstrate that TERS as a powerful analytical tool provides a unique approach to spatially investigate the local structure-reactivity relationship in catalysis.</p>

Nanometer Scale Spectroscopic Visualization of Catalytic Sites During a Hydrogenation Reaction on a Pd/Au Bimetallic Catalyst

2020 ◽  
Author(s):  
Hao Yin ◽  
Liqing Zheng ◽  
Wei Fang ◽  
Yin-Hung Lai ◽  
Nikolaus Porenta ◽  
...  
Keyword(s):  
Catalytic Hydrogenation ◽  
Density Functional ◽  
Hydrogen Transfer ◽  
Bimetallic Catalyst ◽  
Local Environment ◽  
Hydrogenation Reaction ◽  
Boundary Density ◽  
Catalytic Sites ◽  
Powerful Analytical Tool ◽  
Tip Enhanced Raman Spectroscopy

<p>Understanding the mechanism of catalytic hydrogenation at the local environment requires chemical and topographic information involving catalytic sites, active hydrogen species and their spatial distribution. Here, tip-enhanced Raman spectroscopy (TERS) was employed to study the catalytic hydrogenation of chloro-nitrobenzenethiol on a well-defined Pd(sub-monolayer)/Au(111) bimetallic catalyst (<i>p</i><sub>H2</sub>=1.5 bar, 298 K), where the surface topography and chemical fingerprint information were simultaneously mapped with nanoscale resolution (≈10 nm). TERS imaging of the surface after catalytic hydrogenation confirms that the reaction occurs beyond the location of Pd sites. The results demonstrate that hydrogen spillover accelerates hydrogenation at the Au sites within 20 nm from the bimetallic Pd/Au boundary. Density functional theory was used to elucidate the thermodynamics of interfacial hydrogen transfer. We demonstrate that TERS as a powerful analytical tool provides a unique approach to spatially investigate the local structure-reactivity relationship in catalysis.</p>

Catalytic Hydrogenation of Carbon Dioxide to Fuels

2014 ◽  
Vol 18 (10) ◽  
pp. 1335-1345 ◽  
Author(s):  
Xuecheng Yan ◽  
Han Guo ◽  
Dongjiang Yang ◽  
Shilun Qiu ◽  
Xiangdong Yao
Keyword(s):  
Carbon Dioxide ◽  
Catalytic Hydrogenation ◽  
Hydrogenation Of Carbon Dioxide

Tuning the Photocatalytic Performance of Plasmonic Nanocomposites (ZnO/Aux) Driven in Visible Light

2019 ◽  
Vol 8 (1) ◽  
pp. 56-61
Author(s):  
Aneeya K. Samantara ◽  
Debasrita Dash ◽  
Dipti L. Bhuyan ◽  
Namita Dalai ◽  
Bijayalaxmi Jena
Keyword(s):  
Electron Transfer ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Transfer Rate ◽  
Photocatalytic Performance ◽  
Light Exposure ◽  
Au Nanoparticle ◽  
Electron Transfer Rate ◽  
Au Nps ◽  
Zno Nanostructure

: In this article, we explored the possibility of controlling the reactivity of ZnO nanostructures by modifying its surface with gold nanoparticles (Au NPs). By varying the concentration of Au with different wt% (x = 0.01, 0.05, 0.08, 1 and 2), we have synthesized a series of (ZnO/Aux) nanocomposites (NCs). A thorough investigation of the photocatalytic performance of different wt% of Au NPs on ZnO nanosurface has been carried out. It was observed that ZnO/Au0.08 nanocomposite showed the highest photocatalytic activity among all concentrations of Au on the ZnO surface, which degrades the dye concentration within 2 minutes of visible light exposure. It was further revealed that with an increase in the size of plasmonic nanoparticles beyond 0.08%, the accessible surface area of the Au nanoparticle decreases. The photon absorption capacity of Au nanoparticle decreases beyond 0.08% resulting in a decrease in electron transfer rate from Au to ZnO and a decrease of photocatalytic activity. Background: Due to the industrialization process, most of the toxic materials go into the water bodies, affecting the water and our ecological system. The conventional techniques to remove dyes are expensive and inefficient. Recently, heterogeneous semiconductor materials like TiO2 and ZnO have been regarded as potential candidates for the removal of dye from the water system. Objective: To investigate the photocatalytic performance of different wt% of Au NPs on ZnO nanosurface and the effect of the size of Au NPs for photocatalytic performance in the degradation process. Methods: A facile microwave method has been adopted for the synthesis of ZnO nanostructure followed by a reduction of gold salt in the presence of ZnO nanostructure to form the composite. Results: ZnO/Au0.08 nanocomposite showed the highest photocatalytic activity which degrades the dye concentration within 2 minutes of visible light exposure. The schematic mechanism of electron transfer rate was discussed. Conclusion: Raspberry shaped ZnO nanoparticles modified with different percentages of Au NPs showed good photocatalytic behavior in the degradation of dye molecules. The synergetic effect of unique morphology of ZnO and well anchored Au nanostructures plays a crucial role.

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