Atomically dispersed Ni as the active site towards selective hydrogenation of nitroarenes

2019 ◽  
Vol 21 (3) ◽  
pp. 704-711 ◽  
Author(s):  
Fan Yang ◽  
Minjian Wang ◽  
Wei Liu ◽  
Bin Yang ◽  
Ying Wang ◽  
...  
Keyword(s):  
Noble Metal ◽  
Catalytic Hydrogenation ◽  
Selective Hydrogenation ◽  
Porous Carbon ◽  
Active Site ◽  
Active Sites ◽  
Rational Design ◽  
Metal Free

Noble-metal-free catalytic hydrogenation of nitroarenes is achieved through the rational design of atomically dispersed Ni sites on N-doped porous carbon. The outstanding activity of the catalyst originates from the atomic dispersion of Ni active sites with a high Ni–N3 content.

Selective hydrogenation of nitroarenes under mild conditions by the optimization of active sites in a well defined Co@NC catalyst

2020 ◽  
Vol 22 (17) ◽  
pp. 5730-5741
Author(s):  
Shuo Chen ◽  
Li-Li Ling ◽  
Shun-Feng Jiang ◽  
Hong Jiang
Keyword(s):  
Particle Size ◽  
Catalytic Hydrogenation ◽  
Selective Hydrogenation ◽  
Active Sites ◽  
Metal Organic Framework ◽  
Nitro Compounds ◽  
Active Species ◽  
Mild Conditions ◽  
Metal Organic ◽  
Aromatic Nitro

The defined catalyst (Co@NC) is prepared through the pyrolysis of the Co-centered metal–organic framework (MOF), in which Co active species (Co–Nx, surface Co NPs) and particle size play important roles in the catalytic hydrogenation of aromatic nitro compounds.

scholarly journals Back Cover: Microwave-Assisted Selective Hydrogenation of Furfural to Furfuryl Alcohol Employing a Green and Noble Metal-Free Copper Catalyst (ChemSusChem 24/2016)

ChemSusChem ◽  
2016 ◽  
Vol 9 (24) ◽  
pp. 3528-3528 ◽  
Author(s):  
Pedro N. Romano ◽  
João M. A. R. de Almeida ◽  
Yuri Carvalho ◽  
Peter Priecel ◽  
Eduardo Falabella Sousa-Aguiar ◽  
...  
Keyword(s):  
Noble Metal ◽  
Selective Hydrogenation ◽  
Furfuryl Alcohol ◽  
Copper Catalyst ◽  
Metal Free ◽  
Back Cover ◽  
Microwave Assisted

Efficient Noble‐Metal‐Free Catalysts Supported by Three‐Dimensional Ordered Hierarchical Porous Carbon

2020 ◽  
Vol 15 (16) ◽  
pp. 2513-2519
Author(s):  
Weiqiang Zhou ◽  
Wei Liang Teo ◽  
Dongdong Wang ◽  
Gancheng Zuo ◽  
Deblin Jana ◽  
...  
Keyword(s):  
Noble Metal ◽  
Porous Carbon ◽  
Three Dimensional ◽  
Hierarchical Porous Carbon ◽  
Metal Free ◽  
Hierarchical Porous

scholarly journals Covalent organic frameworks in Lieb lattice for tunable photocatalytic water splitting under visible light

2021 ◽  
Author(s):  
Hongde Yu ◽  
Dong Wang
Keyword(s):  
Hydrogen Production ◽  
Water Splitting ◽  
Active Sites ◽  
Rational Design ◽  
Near Infrared ◽  
Band Alignment ◽  
Covalent Organic Frameworks ◽  
Photocatalytic Water Splitting ◽  
Metal Free ◽  
Lieb Lattice

Covalent organic frameworks (COFs) with highly designable skeleton and inherent pores have emerged as promising organic photocatalysts for hydrogen production. However, inefficient solar light harvesting, strong excitonic effect, and the lack of active sites still pose major challenges to the rational design of COFs for efficient photocatalytic water splitting and the structure-property relationship has not been established. In this work, we investigated the fundamental mechanism of photoelectrochemical conversion in fully conjugated donor (D)-acceptor (A) COFs in Lieb lattice and proposed a facile strategy to achieve broad visible and near-infrared absorption, prompt exciton dissociation, tunable band alignment for overall water splitting, and metal-free catalysis of hydrogen production. Interestingly, we found that the exciton binding energy was substantially reduced with the narrowing of optical band gap and the increase of static dielectric constant. Further, we unraveled that the hydrogen bond played a vital role in suppressing the overpotential for hydrogen evolution reaction to enable metal-free catalysis. These findings not only highlight a novel route to modulating electronic properties of COFs towards high photocatalytic activity for water splitting, but also offer tremendous opportunities to design metal-free catalysts for other chemical transformations.

scholarly journals Noble-Metal-Free NixSy-C3N5 Hybrid Nanosheet with Highly Efficient Photocatalytic Performance

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1089
Author(s):  
Lixiao Han ◽  
Cong Peng ◽  
Jinming Huang ◽  
Linhao Sun ◽  
Shengyao Wang ◽  
...  
Keyword(s):  
Noble Metal ◽  
Active Sites ◽  
Photocatalytic Performance ◽  
Low Cost ◽  
H2 Production ◽  
Apparent Quantum Yield ◽  
Metal Free ◽  
Highly Efficient ◽  
Multifunctional Catalyst ◽  
Photocatalytic Applications

The construction of highly efficient, low-cost and noble-metal-free photocatalysts depends on photocatalytic technology. Recently, N-rich C3N5 has been explored as a novel carbon nitride material with a much narrower band gap (~2.2 eV) than that of traditional C3N4 (~2.7 eV). Planting noble-metal-free active sites on C3N5 to improve its photocatalytic activity is of great significance. Herein, 2D NixSy nanosheet is facially loaded on 2D C3N5 using a hydrothermal procedure under a low temperature. Due to the quick separation of photogenerated carries between C3N5 and NixSy, this inexpensive noble-metal-free NixSy-C3N5 hybrid nanosheet is highly efficient and stable as a multifunctional catalyst in various applications, including photocatalytic H2 production from water and NO removal. Impressively, the apparent quantum yield (AQY) value for H2 production reaches 37.0% (at 420 nm) on optimal NixSy-C3N5 hybrids, which is much higher than that of Pt-C3N5 material. This work opens an avenue to the fabrication of low-cost and noble-metal-free catalysts for multifunctional photocatalytic applications.

scholarly journals Graphene/nitrogen-doped porous carbon sandwiches for the metal-free oxygen reduction reaction: conductivity versus active sites

2016 ◽  
Vol 4 (32) ◽  
pp. 12658-12666 ◽  
Author(s):  
M. Qiao ◽  
C. Tang ◽  
G. He ◽  
K. Qiu ◽  
R. Binions ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Porous Carbon ◽  
Active Sites ◽  
Electronic Conductivity ◽  
Hydrothermal Carbonization ◽  
Reduction Reaction ◽  
Active Nitrogen ◽  
Free Oxygen ◽  
Nitrogen Doped ◽  
Metal Free

Graphene/nitrogen-doped porous carbon sandwiches were prepared by hydrothermal carbonization. Once the electronic conductivity in the carbon–carbon hybrids reaches a certain value, the performance is controlled by the active nitrogen sites.

scholarly journals Engineering Ternary Copper-Cobalt Sulfide Nanosheets as High-performance Electrocatalysts toward Oxygen Evolution Reaction

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 459 ◽  
Author(s):  
Heng Luo ◽  
Hang Lei ◽  
Yufei Yuan ◽  
Yongyin Liang ◽  
Yi Qiu ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Noble Metal ◽  
Oxygen Evolution Reaction ◽  
Water Oxidation ◽  
Active Sites ◽  
High Performance ◽  
Rational Design ◽  
Renewable Energy Sources ◽  
Cobalt Sulfide ◽  
Carbon Cloth

The rational design and development of the low-cost and effective electrocatalysts toward oxygen evolution reaction (OER) are essential in the storage and conversion of clean and renewable energy sources. Herein, a ternary copper-cobalt sulfide nanosheets electrocatalysts (denoted as CuCoS/CC) for electrochemical water oxidation has been synthesized on carbon cloth (CC) via the sulfuration of CuCo-based precursors. The obtained CuCoS/CC reveals excellent electrocatalytic performance toward OER in 1.0 M KOH. It exhibits a particularly low overpotential of 276 mV at current density of 10 mA cm−2, and a small Tafel slope (58 mV decade−1), which is superior to the current commercialized noble-metal electrocatalysts, such as IrO2. Benefiting from the synergistic effect of Cu and Co atoms and sulfidation, electrons transport and ions diffusion are significantly enhanced with the increase of active sites, thus the kinetic process of OER reaction is boosted. Our studies will serve as guidelines in the innovative design of non-noble metal electrocatalysts and their application in electrochemical water splitting

Template-free synthesis of polyacrylonitrile-derived porous carbon nanoballs on graphene for efficient oxygen reduction in zinc–air batteries

2021 ◽  
Vol 9 (15) ◽  
pp. 9644-9654
Author(s):  
Halima Begum ◽  
Mohammad Shamsuddin Ahmed ◽  
Seunghun Jung
Keyword(s):  
Fuel Cells ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Porous Carbon ◽  
Active Sites ◽  
Reduction Reaction ◽  
Metal Free ◽  
Template Free ◽  
Energy Conversion Devices ◽  
Zinc Air Batteries

Introducing abundant active sites and improving their activity are two critical considerations for designing metal-free nitrogenous electrocatalysts for the oxygen reduction reaction (ORR) in energy conversion devices such as metal–air batteries and fuel cells.

scholarly journals NMPylation and de-NMPylation of SARS-CoV-2 Nsp9 by the NiRAN domain

2021 ◽  
Author(s):  
Bing Wang ◽  
Dmitri Svetlov ◽  
Irina Artsimovitch
Keyword(s):  
Active Site ◽  
Active Sites ◽  
Rational Design ◽  
Rna Synthesis ◽  
Rna Binding ◽  
Catalytic Reactions ◽  
Mechanistic Studies ◽  
Rna Dependent Rna Polymerase ◽  
Nucleotide Analogs ◽  
Nucleotidyl Transferase

Nsp12, the catalytic subunit of SARS-CoV-2 RNA-dependent RNA polymerase (RdRp), contains two active sites that catalyze nucleotidyl-monophosphate (NMP) transfer (NMPylation). RNA synthesis is mediated by the RdRp active site that is conserved among all RNA viruses and has been a focus of mechanistic studies and drug discovery. The second active site resides in a Nidovirus RdRp-Associated Nucleotidyl transferase (NiRAN) domain. Both catalytic reactions are essential for viral replication, but the mechanism and targets of NiRAN are poorly characterized. One recent study showed that NiRAN transfers NMP to the first residue of RNA-binding protein Nsp9. Another study reported a structure of SARS-CoV-2 replicase with an extended Nsp9 in the NiRAN active site but observed NMP transfer to RNA instead. We show that SARS-CoV-2 Nsp12 efficiently and reversibly NMPylates the native but not the extended Nsp9. Substitutions of the invariant NiRAN residues abolish NMPylation, whereas a substitution of a catalytic RdRp Asp residue does not. NMPylation is inhibited by nucleotide analogs, pyrophosphate, and bisphosphonates, suggesting a path for rational design of NiRAN inhibitors. We hypothesize that Nsp9 remodels both active sites of Nsp12 to support initiation of RNA synthesis by RdRp and subsequent capping of the product RNA by the NiRAN domain.

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