Fe-N4 and Co-N4 dual sites for boosting oxygen electroreduction in Zn-air batteries

2021 ◽  
Author(s):  
Dan Wang ◽  
Hao Xu ◽  
Peixia Yang ◽  
Xiangyu Lu ◽  
Jingyuan Ma ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Active Sites ◽  
Oxygen Electroreduction ◽  
Individual Metal ◽  
Dual Metal ◽  
The Individual

Compared to the individual metal sites, e.g. Fe-N4 site, the synergistic effect of the dual-metal sites can further adjust the interaction of the reactants or intermediates with the active sites,...

scholarly journals Synergistic Effect of Alkali Na and K Promoter on Fe-Co-Cu-Al Catalysts for CO2 Hydrogenation to Light Hydrocarbons

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 735
Author(s):  
Yuhao Zheng ◽  
Chenghua Xu ◽  
Xia Zhang ◽  
Qiong Wu ◽  
Jie Liu
Keyword(s):  
Synergistic Effect ◽  
Active Sites ◽  
Intermediate Formation ◽  
Active Phase ◽  
Dissociative Adsorption ◽  
Co2 Hydrogenation ◽  
Chain Growth ◽  
Co2 Conversion ◽  
Light Hydrocarbons ◽  
Active Centers

Alkali metal K- and/or Na-promoted FeCoCuAl catalysts were synthesized by precipitation and impregnation, and their physicochemical and catalytic performance for CO2 hydrogenation to light hydrocarbons was also investigated in the present work. The results indicate that Na and/or K introduction leads to the formation of active phase metallic Fe and Fe-Co crystals in the order Na < K < K-Na. The simultaneous introduction of Na and K causes a synergistic effect on increasing the basicity and electron-rich property, promoting the formation of active sites Fe@Cu and Fe-Co@Cu with Cu0 as a crystal core. These effects are advantageous to H2 dissociative adsorption and CO2 activation, giving a high CO2 conversion with hydrogenation. Moreover, electron-rich Fe@Cu (110) and Fe-Co@Cu (200) provide active centers for further H2 dissociative adsorption and O-C-Fe intermediate formation after adsorption of CO produced by RWGS. It is beneficial for carbon chain growth in C2+ hydrocarbons, including olefins and alkanes. FeCoCuAl simultaneously modified by K-Na exhibits the highest CO2 conversion and C2+ selectivity of 52.87 mol% and 89.70 mol%, respectively.

Fast identification of stability of atomically dispersed bi-atom catalysts by a structure descriptor-based model

2022 ◽  
Author(s):  
Danyang LI ◽  
Haoxiang Xu ◽  
Jiqin Zhu ◽  
Dapeng Cao
Keyword(s):  
Synergistic Effect ◽  
Active Sites ◽  
Catalytic Performance ◽  
Fast Identification ◽  
Structure Descriptor

Atomically dispersed bi-atom catalysts (BACs) exhibit remarkable catalytic performance in a variety of reactions due to the adjacent coordination-unsaturated metal active sites, as well as interatomic synergistic effect. However, high-efficiently...

Rational design of atomically dispersed nickel active sites in β-Mo2C for the hydrogen evolution reaction at all pH values

2018 ◽  
Vol 54 (71) ◽  
pp. 9901-9904 ◽  
Author(s):  
Ting Ouyang ◽  
An-Na Chen ◽  
Zhen-Zhao He ◽  
Zhao-Qing Liu ◽  
Yexiang Tong
Keyword(s):  
Synergistic Effect ◽  
Electrochemical Properties ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Rational Design ◽  
Efficient Catalyst ◽  
Ph Values ◽  
Ni Species

Atomically dispersed Ni in β-Mo2C (Ni/β-Mo2C) is designed as an efficient catalyst for the HER at all pH values. The remarkable electrochemical properties of Ni/β-Mo2C are mainly attributed to the synergistic effect between atomically dispersed Ni species and β-Mo2C.

scholarly journals A Novel CdS Quantum Dots Decorated 3D Bi2O2CO3 Hierarchical Nanoflower with Enhanced Photocatalytic Performance

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1046 ◽  
Author(s):  
Zhilin Ji ◽  
Hongwei Wang ◽  
Xilin She
Keyword(s):  
Quantum Dots ◽  
Synergistic Effect ◽  
Rhodamine B ◽  
Active Sites ◽  
Photocatalytic Performance ◽  
High Efficiency ◽  
Environmental Pollutants ◽  
Cds Quantum Dots ◽  
Design And Synthesis ◽  
Cds Qds

Heterojunction engineering has shown great potential in the field of photocatalysis to deal with environmental pollutants. The design and synthesis of heterojunction photocatalysts with high efficiency and stability still face great challenges. In this work, a novel CdS quantum dots (QDs) decorated 3D Bi2O2CO3 hierarchical nanoflower heterojunction photocatalyst (Bi2O2CO3/CdS QDs) was synthesized to investigate the photocatalytic Rhodamine B (RhB) degradation performance. CdS QDs were evenly distributed on the surface of the Bi2O2CO3 nanoflower. Bi2O2CO3/CdS QDs showed significantly enhanced photocatalytic RhB degradation performance compared with pristine Bi2O2CO3 and CdS QDs. The enhanced photocatalytic performance was attributed to the synergistic effect of hierarchical structure and heterojunction, which greatly increased the active sites of the reaction and the photogenerated carriers transfer.

scholarly journals Author Correction: Atomic layer deposited Pt-Ru dual-metal dimers and identifying their active sites for hydrogen evolution reaction

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Lei Zhang ◽  
Rutong Si ◽  
Hanshuo Liu ◽  
Ning Chen ◽  
Qi Wang ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Atomic Layer ◽  
Dual Metal

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Ultrathin NiCo2O4 nanosheets with dual-metal active sites for enhanced solar water splitting of a BiVO4 photoanode

2019 ◽  
Vol 7 (39) ◽  
pp. 22274-22278 ◽  
Author(s):  
Chenchen Feng ◽  
Qi Zhou ◽  
Bin Zheng ◽  
Xiang Cheng ◽  
Yajun Zhang ◽  
...  
Keyword(s):  
Water Splitting ◽  
Water Oxidation ◽  
Active Sites ◽  
Oxygen Vacancies ◽  
Solar Water ◽  
Solar Water Splitting ◽  
Highly Efficient ◽  
Dual Metal ◽  
Nico2o4 Nanosheets ◽  
First Time

Spinel-structured NiCo2O4 nanosheets with dual-metal active sites, an ultrathin structure, and abundant oxygen vacancies were decorated for the first time on a BiVO4 photoanode for highly efficient PEC water oxidation.

scholarly journals Fungi in association with chronic bacterial rhinosinusitis; relationship with a synergistic effect: a prospective study

2018 ◽  
Vol 4 (5) ◽  
pp. 1272
Author(s):  
Namit Kant Singh ◽  
Lakshmi Narayan Garg ◽  
Shubhranshu Shekhar ◽  
Naiya Rao ◽  
Chandpreet Kour ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Chronic Rhinosinusitis ◽  
Strong Association ◽  
Average Score ◽  
Microbial Infection ◽  
Nasal Blockage ◽  
Bacteria And Fungi ◽  
The Individual ◽  
A Prospective Study

<p class="abstract"><strong>Background:</strong> The role of fungi as an etiological factor in the causation of chronic rhinosinusitis remains uncertain. The interaction of Fungi with bacteria can result formation of mixed biofilm which provide symbiotic relationship along with resistance from antimicrobials with an increased severity of symptoms.</p><p class="abstract"><strong>Methods:</strong> The cases of chronic rhinosinusitis were diagnosed and the grading of the symptom severity was done by visual analog scale in which symptoms of nasal blockage, rhinorrhea or post nasal drip, facial pain/headache, loss of smell, sleep disturbance/ fatigue were taken into consideration and each of the symptoms was graded from 1 to 10.  </p><p class="abstract"><strong>Results:</strong> A strong association was detected between bacteria and fungi as 37 out of 40 (92.5%) amongst cases and 31 out of 40 (77.5%) amongst controls showed growth of both the organisms. Cases who were detected of having Fungi with Bacteria were having an average score of 8.364 and cases with bacteria alone were having an average score of 6.36. taking into consideration the individual symptom score and analyzing the data, the comparison between cases having both bacteria and fungi and cases with bacteria alone was found to be statistically significant with a p one-tail= 0.010221 and p two-tail= 0.020442.</p><p class="abstract"><strong>Conclusions:</strong> In chronic rhinosinusitis there is a higher incidence of poly microbial infection, and bacteria along with fungi co-exist with a synergistic effect leading to a higher morbidity.</p>

scholarly journals Evaluation of the Individual and Combined Toxicity of Fumonisin Mycotoxins in Human Gastric Epithelial Cells

2020 ◽  
Vol 21 (16) ◽  
pp. 5917
Author(s):  
Song Yu ◽  
Bingxuan Jia ◽  
Na Liu ◽  
Dianzhen Yu ◽  
Aibo Wu
Keyword(s):  
Synergistic Effect ◽  
Fumonisin B1 ◽  
Potential Method ◽  
Assessment Method ◽  
Antagonistic Effect ◽  
Epithelial Cell Line ◽  
High Concentration ◽  
Food And Feed ◽  
The Individual

Fumonisin contaminates food and feed extensively throughout the world, causing chronic and acute toxicity in human and animals. Currently, studies on the toxicology of fumonisins mainly focus on fumonisin B1 (FB1). Considering that FB1, fumonisin B2 (FB2) and fumonisin B3 (FB3) could coexist in food and feed, a study regarding a single toxin, FB1, may not completely reflect the toxicity of fumonisin. The gastrointestinal tract is usually exposed to these dietary toxins. In our study, the human gastric epithelial cell line (GES-1) was used as in vitro model to evaluate the toxicity of fumonisin. Firstly, we found that they could cause a decrease in cell viability, and increase in membrane leakage, cell death and the induction of expression of markers for endoplasmic reticulum (ER) stress. Their toxicity potency rank is FB1 > FB2 >> FB3. The results also showed that the synergistic effect appeared in the combinations of FB1 + FB2 and FB1 + FB3. Nevertheless, the combinations of FB2 + FB3 and FB1 + FB2 + FB3 showed a synergistic effect at low concentration and an antagonistic effect at high concentration. We also found that myriocin (ISP-1) could alleviate the cytotoxicity induced by fumonisin in GES-1 cells. Finally, this study may help to determine or optimize the legal limits and risk assessment method of mycotoxins in food and feed and provide a potential method to block the fumonisin toxicity.

Crystal structure of the pseudoenzyme PDX1.2 in complex with its cognate enzyme PDX1.3: a total eclipse

2019 ◽  
Vol 75 (4) ◽  
pp. 400-415 ◽  
Author(s):  
Graham C. Robinson ◽  
Markus Kaufmann ◽  
Céline Roux ◽  
Jacobo Martinez-Font ◽  
Michael Hothorn ◽  
...  
Keyword(s):  
Active Sites ◽  
Protein Complexes ◽  
Structural Similarity ◽  
Cellular Protein ◽  
Vitamin B ◽  
Protein Activity ◽  
X Ray ◽  
X Ray Crystallography ◽  
The Individual ◽  
High Degree

Pseudoenzymes have burst into the limelight recently as they provide another dimension to regulation of cellular protein activity. In the eudicot plant lineage, the pseudoenzyme PDX1.2 and its cognate enzyme PDX1.3 interact to regulate vitamin B6 biosynthesis. This partnership is important for plant fitness during environmental stress, in particular heat stress. PDX1.2 increases the catalytic activity of PDX1.3, with an overall increase in vitamin B6 biosynthesis. However, the mechanism by which this is achieved is not known. In this study, the Arabidopsis thaliana PDX1.2–PDX1.3 complex was crystallized in the absence and presence of ligands, and attempts were made to solve the X-ray structures. Three PDX1.2–PDX1.3 complex structures are presented: the PDX1.2–PDX1.3 complex as isolated, PDX1.2–PDX1.3-intermediate (in the presence of substrates) and a catalytically inactive complex, PDX1.2–PDX1.3-K97A. Data were also collected from a crystal of a selenomethionine-substituted complex, PDX1.2–PDX1.3-SeMet. In all cases the protein complexes assemble as dodecamers, similar to the recently reported individual PDX1.3 homomer. Intriguingly, the crystals of the protein complex are statistically disordered owing to the high degree of structural similarity of the individual PDX1 proteins, such that the resulting configuration is a composite of both proteins. Despite the differential methionine content, selenomethionine substitution of the PDX1.2–PDX1.3 complex did not resolve the problem. Furthermore, a comparison of the catalytically competent complex with a noncatalytic complex did not facilitate the resolution of the individual proteins. Interestingly, another catalytic lysine in PDX1.3 (Lys165) that pivots between the two active sites in PDX1 (P1 and P2), and the corresponding glutamine (Gln169) in PDX1.2, point towards P1, which is distinctive to the initial priming for catalytic action. This state was previously only observed upon trapping PDX1.3 in a catalytically operational state, as Lys165 points towards P2 in the resting state. Overall, the study shows that the integration of PDX1.2 into a heteromeric dodecamer assembly with PDX1.3 does not cause a major structural deviation from the overall architecture of the homomeric complex. Nonetheless, the structure of the PDX1.2–PDX1.3 complex highlights enhanced flexibility in key catalytic regions for the initial steps of vitamin B6 biosynthesis. This report highlights what may be an intrinsic limitation of X-ray crystallography in the structural investigation of pseudoenzymes.

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