Multistep protection strategy for preparation of atomically dispersed Fe-N catalyst for selective oxidation of ethylbenzene to acetophenone

2021 ◽  
Author(s):  
Hong Zhao ◽  
Jian Fang ◽  
Dan Xu ◽  
Jianfeng Li ◽  
Boyang Li ◽  
...  
Keyword(s):  
Selective Oxidation ◽  
Active Sites ◽  
Research Topic ◽  
Single Atom ◽  
Protection Strategy ◽  
Oxidation Of Ethylbenzene ◽  
Controllable Preparation

The fabrication of catalysts with atomically dispersed metal active sites is a hot research topic in catalysis, but the controllable preparation of single-atom catalysts still possesses several challenges due to...

Protein powder derived nitrogen-doped carbon supported atomically dispersed iron sites for selective oxidation of ethylbenzene

2021 ◽  
Vol 50 (34) ◽  
pp. 11711-11715
Author(s):  
Yujie Cheng ◽  
Qingdi Sun ◽  
Liyun Huang ◽  
Qian He ◽  
Hao Zhang ◽  
...  
Keyword(s):  
Nitrogen Source ◽  
Ball Milling ◽  
Selective Oxidation ◽  
Single Atom ◽  
Nitrogen Doped ◽  
Oxidation Of Ethylbenzene ◽  
Nitrogen Doped Carbon

A single atom catalyst Fe1/NC, synthesized by ball milling with protein powder as the nitrogen source, exhibited superb performance for selective oxidation of ethylbenzene.

scholarly journals Insights on forming N,O-coordinated Cu single-atom catalysts for electrochemical reduction CO2 to methane

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yanming Cai ◽  
Jiaju Fu ◽  
Yang Zhou ◽  
Yu-Chung Chang ◽  
Qianhao Min ◽  
...  
Keyword(s):  
Energy Barrier ◽  
Active Sites ◽  
Theoretical Calculations ◽  
High Energy ◽  
Single Atom ◽  
Faradaic Efficiency ◽  
High Energy Barrier ◽  
Catalytic Sites ◽  
Electron Reduction ◽  
First Time

AbstractSingle-atom catalysts (SACs) are promising candidates to catalyze electrochemical CO2 reduction (ECR) due to maximized atomic utilization. However, products are usually limited to CO instead of hydrocarbons or oxygenates due to unfavorable high energy barrier for further electron transfer on synthesized single atom catalytic sites. Here we report a novel partial-carbonization strategy to modify the electronic structures of center atoms on SACs for lowering the overall endothermic energy of key intermediates. A carbon-dots-based SAC margined with unique CuN2O2 sites was synthesized for the first time. The introduction of oxygen ligands brings remarkably high Faradaic efficiency (78%) and selectivity (99% of ECR products) for electrochemical converting CO2 to CH4 with current density of 40 mA·cm-2 in aqueous electrolytes, surpassing most reported SACs which stop at two-electron reduction. Theoretical calculations further revealed that the high selectivity and activity on CuN2O2 active sites are due to the proper elevated CH4 and H2 energy barrier and fine-tuned electronic structure of Cu active sites.

scholarly journals Manganese vacancy-confined single-atom Ag in cryptomelane nanorods for efficient Wacker oxidation of styrene derivatives

2021 ◽  
Author(s):  
Hongling Yang ◽  
Xun Zhang ◽  
Yi Yu ◽  
Zheng Chen ◽  
Qinggang Liu ◽  
...  
Keyword(s):  
Molecular Sieve ◽  
Active Sites ◽  
Single Atom ◽  
Wacker Oxidation ◽  
Catalytically Active ◽  
Styrene Derivatives

Single-atom catalysts provide a pathway to elucidate the nature of catalytically active sites. However, keeping them stabilized during operation proves to be challenging. Herein, we employ cryptomelane-type octahedral molecular sieve...

scholarly journals Shifting the scaling relations of single-atom catalysts for facile methane activation by tuning the coordination number

2021 ◽  
Author(s):  
Changhyeok Choi ◽  
Sungho Yoon ◽  
Yousung Jung
Keyword(s):  
Transition State ◽  
Coordination Number ◽  
Active Sites ◽  
Methane Activation ◽  
Single Atom ◽  
Scaling Relations ◽  
Scaling Relationship ◽  
Relationship Of

The scaling relationship of methane activation via a radical-like transition state shifts toward a more reactive region with decreasing coordination number of the active sites.

scholarly journals Engineering single-atomic ruthenium catalytic sites on defective nickel-iron layered double hydroxide for overall water splitting

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Panlong Zhai ◽  
Mingyue Xia ◽  
Yunzhen Wu ◽  
Guanghui Zhang ◽  
Junfeng Gao ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Water Splitting ◽  
Layered Double Hydroxide ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Density Functional ◽  
Rational Design ◽  
Single Atom ◽  
Nickel Iron ◽  
Double Hydroxide

AbstractRational design of single atom catalyst is critical for efficient sustainable energy conversion. However, the atomic-level control of active sites is essential for electrocatalytic materials in alkaline electrolyte. Moreover, well-defined surface structures lead to in-depth understanding of catalytic mechanisms. Herein, we report a single-atomic-site ruthenium stabilized on defective nickel-iron layered double hydroxide nanosheets (Ru1/D-NiFe LDH). Under precise regulation of local coordination environments of catalytically active sites and the existence of the defects, Ru1/D-NiFe LDH delivers an ultralow overpotential of 18 mV at 10 mA cm−2 for hydrogen evolution reaction, surpassing the commercial Pt/C catalyst. Density functional theory calculations reveal that Ru1/D-NiFe LDH optimizes the adsorption energies of intermediates for hydrogen evolution reaction and promotes the O–O coupling at a Ru–O active site for oxygen evolution reaction. The Ru1/D-NiFe LDH as an ideal model reveals superior water splitting performance with potential for the development of promising water-alkali electrocatalysts.

Atomic regulation of metal-organic framework derived carbon-based single-atom catalysts for electrochemical CO2 reduction reaction

2021 ◽  
Author(s):  
Danni Zhou ◽  
Xinyuan Li ◽  
Huishan Shang ◽  
Fengjuan Qin ◽  
Wenxing Chen
Keyword(s):  
Active Sites ◽  
Metal Organic Framework ◽  
Co2 Reduction ◽  
Carbon Dioxide Reduction ◽  
Reduction Reaction ◽  
Single Atom ◽  
Electrochemical Co2 Reduction ◽  
Metal Organic ◽  
Co2 Reduction Reaction ◽  
Organic Framework

Metal-organic framework (MOF) derived single-atom catalysts (SACs), featured unique active sites and adjustable topological structures, exhibit high electrocatalytic performance on carbon dioxide reduction reactions (CO2RR). By modulating elements and atomic...

scholarly journals Substrate strain tunes operando geometric distortion and oxygen reduction activity of CuN2C2 single-atom sites

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guokang Han ◽  
Xue Zhang ◽  
Wei Liu ◽  
Qinghua Zhang ◽  
Zhiqiang Wang ◽  
...  
Keyword(s):  
Structure Function ◽  
Oxygen Reduction ◽  
Active Sites ◽  
Geometric Distortion ◽  
Single Atom ◽  
Reduction Activity ◽  
Activity Promotion ◽  
Structure Function Relationship ◽  
Substrate Strain ◽  
Function Relationship

AbstractSingle-atom catalysts are becoming increasingly significant to numerous energy conversion reactions. However, their rational design and construction remain quite challenging due to the poorly understood structure–function relationship. Here we demonstrate the dynamic behavior of CuN2C2 site during operando oxygen reduction reaction, revealing a substrate-strain tuned geometry distortion of active sites and its correlation with the activity. Our best CuN2C2 site, on carbon nanotube with 8 nm diameter, delivers a sixfold activity promotion relative to graphene. Density functional theory and X-ray absorption spectroscopy reveal that reasonable substrate strain allows the optimized distortion, where Cu bonds strongly with the oxygen species while maintaining intimate coordination with C/N atoms. The optimized distortion facilitates the electron transfer from Cu to the adsorbed O, greatly boosting the oxygen reduction activity. This work uncovers the structure–function relationship of single-atom catalysts in terms of carbon substrate, and provides guidance to their future design and activity promotion.

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