scholarly journals Searching novel complex solid solution electrocatalysts in unconventional element combinations

Nano Research ◽  
2021 ◽  
Author(s):  
Olga A. Krysiak ◽  
Simon Schumacher ◽  
Alan Savan ◽  
Wolfgang Schuhmann ◽  
Alfred Ludwig ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Active Sites ◽  
Search Space ◽  
Reduction Reaction ◽  
Film Material ◽  
X Ray ◽  
High Entropy ◽  
Catalyst Composition ◽  
Scanning Transmission

AbstractDespite outstanding accomplishments in catalyst discovery, finding new, more efficient, environmentally neutral, and noble metal-free catalysts remains challenging and unsolved. Recently, complex solid solutions consisting of at least five different elements and often named as high-entropy alloys have emerged as a new class of electrocatalysts for a variety of reactions. The multicomponent combinations of elements facilitate tuning of active sites and catalytic properties. Predicting optimal catalyst composition remains difficult, making testing of a very high number of them indispensable. We present the high-throughput screening of the electrochemical activity of thin film material libraries prepared by combinatorial co-sputtering of metals which are commonly used in catalysis (Pd, Cu, Ni) combined with metals which are not commonly used in catalysis (Ti, Hf, Zr). Introducing unusual elements in the search space allows discovery of catalytic activity for hitherto unknown compositions. Material libraries with very similar composition spreads can show different activities vs. composition trends for different reactions. In order to address the inherent challenge of the huge combinatorial material space and the inability to predict active electrocatalyst compositions, we developed a high-throughput process based on co-sputtered material libraries, and performed high-throughput characterization using energy dispersive X-ray spectroscopy (EDS), scanning transmission electron microscopy (SEM), X-ray diffraction (XRD) and conductivity measurements followed by electrochemical screening by means of a scanning droplet cell. The results show surprising material compositions with increased activity for the oxygen reduction reaction and the hydrogen evolution reaction. Such data are important input data for future data-driven materials prediction.

Role of the Structure and Electronic Properties of Fe2O3-MoO3 Catalyst on the Dehydration of Isopropyl Alcohol

1993 ◽  
Vol 58 (7) ◽  
pp. 1591-1599 ◽  
Author(s):  
Abd El-Aziz A. Said
Keyword(s):  
Active Sites ◽  
Isopropyl Alcohol ◽  
Oxide Catalyst ◽  
Flow System ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalyst Composition ◽  
Surface Active

Molybdenum oxide catalyst doped or mixed with (1 - 50) mole % Fe3+ ions were prepared. The structure of the original samples and the samples calcined at 400 °C were characterized using DTA, X-ray diffraction and IR spectra. Measurements of the electrical conductivity of calcined samples with and without isopropyl alcohol revealed that the conductance increases on increasing the content of Fe3+ ions up to 50 mole %. The activation energies of charge carriers were determined in presence and absence of the alcohol. The catalytic dehydration of isopropyl alcohol was carried out at 250 °C using a flow system. The results obtained showed that the doped or mixed catalysts are active and selective towards propene formation. However, the catalyst containing 40 mole % Fe3+ ions exhibited the highest activity and selectivity. Correlations were attempted to the catalyst composition with their electronic and catalytic properties. Probable mechanism for the dehydration process is proposed in terms of surface active sites.

scholarly journals Metallic Organic Framework-Derived Fe, N, S co-doped Carbon as a Robust Catalyst for the Oxygen Reduction Reaction in Microbial Fuel Cells

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3846 ◽  
Author(s):  
Xiao Luo ◽  
Wuli Han ◽  
Han Ren ◽  
Qingzuo Zhuang
Keyword(s):  
Fuel Cells ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Microbial Fuel Cells ◽  
Active Sites ◽  
Reduction Reaction ◽  
Alkaline Media ◽  
X Ray ◽  
Co Doped ◽  
Organic Framework

Oxygen reduction reaction (ORR) provides a vital role for microbial fuel cells (MFCs) due to its slow reaction kinetics compared with the anodic oxidation reaction. How to develop new materials with low cost, high efficacy, and eco-friendliness which could replace platinum-based electrocatalysis is a challenge that we have to resolve. In this work, we accomplished this successfully by means of a facile strategy to synthesize a metallic organic framework-derived Fe, N, S co-doped carbon with FeS as the main phase. The Fe/S@N/C-0.5 catalyst demonstrated outstandingly enhanced ORR activity in neutral PBS and alkaline media, compared to that of commercial 20% Pt-C catalyst. Here, we started-up and operated two parallel single-chamber microbial fuel cells of an air cathode, and those cathode catalysts were Fe/S@N/C-0.5 and commercial Pt-C (20% Pt), respectively. Scanning electron microscopy (SEM) elaborated that the Fe/S@N/C-0.5 composite did not change the polyhedron morphology of ZIF-8. According to X-ray diffractometry(XRD) curves, the main crystal phase of the resulted Fe/S@N/C-0.5 was FeS. The chemical environment of N, S, and Fe which are anticipated to be the high-efficiency active sites of ORR for MFCs were investigated by X-ray photoelectron spectroscopic(XPS). Nitrogen adsorption/desorption techniques were used to calculate the pore diameter distribution. In brief, the obtained Fe/S@N/C-0.5 material exhibited a pronounced reduction potential at 0.861 V (versus Reversible Hydrogen Electrode(RHE)) in 0.1M KOH solution and –0.03 V (vs. SCE) in the PBS solution, which both outperform the benchmark platinum-based catalysts. Fe/S@N/C-0.5-MFC had a higher Open Circuit Voltage(OCV) (0.71 V), stronger maximum power density (1196 mW/m2), and larger output voltage (0.47 V) than the Pt/C-MFC under the same conditions.

Investigation of Carbon Composition for Electrochemical Properties as PEMFC Cathode Catalyst

2019 ◽  
Vol 964 ◽  
pp. 13-18 ◽  
Author(s):  
Vuri Ayu Setyowati ◽  
Diah Susanti ◽  
Lukman Noerochim ◽  
Eriek Wahyu Restu Widodo ◽  
Mohammad Yusuf Sulaiman
Keyword(s):  
Electrochemical Properties ◽  
Oxygen Reduction ◽  
Active Sites ◽  
High Performance ◽  
Reduction Reaction ◽  
Chemical Compositions ◽  
Cathode Catalyst ◽  
Large Area ◽  
X Ray ◽  
Carbon Composition

Nitrogen –doped carbon material using non-precious metal was developed as catalyst fuel cell (PEMFC). In the PEMFC, the cathode reaction occurs three times slower than anode reaction. Oxygen reduction reaction (ORR) in the cathode has major limit performance. Pt/C was used as high-cost catalyst materials but many researchers concerned to improve cathode catalyst performance using high-performance and low-cost materials. Nitrogen based active sites on carbon has important role for oxygen reduction reactions process. In this study, compositions of carbon for Fe-N-C were investigated to understand the electrochemical properties and morphological analysis. Urea and PVP as nitrogen (N) source was mixed with graphite (Gt). The ratio of Gt and N were 1:1, 3:1, and 1:3. The mixture was added to FeCl3.6H2O dissolved in ethanol to produce Fe-N/C catalyst. Subsequently powder was introduced to the furnace for the pyrolysis. The catalyst products were analyzed using Potentiostat to show the electrochemical properties of catalyst, X-Ray Diffractometer (XRD) was used to know the compound or phases after catalyst syntheses, Scanning Electron Microscope – Energy Dispersive X-Ray (SEM-EDX) was used to identify the morphology and the chemical compositions of catalyst. As a result, Fe – Gt : N = 1:3 catalyst had the greatest electrochemical properties which is identified by large area of CV curve. This catalyst also had the highest current density for reduction reaction. The presence of Fe2O3 and FeS caused the degreasing of catalytic activity. As conclusions of this research, carbon composition had the important rule to improve the ORR activity.

scholarly journals A High-Throughput Screening Triage Workflow to Authenticate a Novel Series of PFKFB3 Inhibitors

2017 ◽  
Vol 23 (1) ◽  
pp. 11-22
Author(s):  
Stephen A. St-Gallay ◽  
Neil Bennett ◽  
Susan E. Critchlow ◽  
Nicola Curtis ◽  
Gareth Davies ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Isothermal Calorimetry ◽  
Binding Mode ◽  
Carbonyl Oxygen ◽  
Enzyme Concentration ◽  
Titration Calorimetry ◽  
X Ray ◽  
X Ray Crystallography ◽  
The Hill

A high-throughput screen (HTS) of human 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) resulted in several series of compounds with the potential for further optimization. Informatics was used to identify active chemotypes with lead-like profiles and remove compounds that commonly occurred as actives in other HTS screens. The activities were confirmed with IC50 measurements from two orthogonal assay technologies, and further analysis of the Hill slopes and comparison of the ratio of IC50 values at 10 times the enzyme concentration were used to identify artifact compounds. Several series of compounds were rejected as they had both high slopes and poor ratios. A small number of compounds representing the different leading series were assessed using isothermal titration calorimetry, and the X-ray crystal structure of the complex with PFKFB3 was solved. The orthogonal assay technology and isothermal calorimetry were demonstrated to be unreliable in identifying false-positive compounds in this case. Presented here is the discovery of the dihydropyrrolopyrimidinone series of compounds as active and novel inhibitors of PFKFB3, shown by X-ray crystallography to bind to the adenosine triphosphate site. The crystal structures of this series also reveal it is possible to flip the binding mode of the compounds, and the alternative orientation can be driven by a sigma-hole interaction between an aromatic chlorine atom and a backbone carbonyl oxygen. These novel inhibitors will enable studies to explore the role of PFKFB3 in driving the glycolytic phenotype of tumors.

scholarly journals Fragment-based screening by X-ray crystallography: an alternative to high throughput screening

2005 ◽  
Vol 61 (a1) ◽  
pp. c246-c246
Author(s):  
A. Cleasby ◽  
L. Devine ◽  
M. Frederickson ◽  
M. Hartshorn ◽  
I. Tickle ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
X Ray ◽  
X Ray Crystallography

scholarly journals Assessing the stability of Pd-exchanged sites in zeolites with the aid of a high throughput quantum chemistry workflow

2021 ◽  
Author(s):  
Hassan Aljama ◽  
Martin Head-Gordon ◽  
Alexis Bell
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Active Sites ◽  
Density Functional ◽  
Functional Materials ◽  
No Adsorption ◽  
Functional Theory ◽  
Wide Range ◽  
The Stability ◽  
Shed Light

Abstract Cation exchanged-zeolites are functional materials with a wide range of applications from catalysis to sorbents. They present a challenge for computational studies using density functional theory due to the numerous possible active sites. From Al configuration, to placement of extra framework cation(s), to potentially different oxidation states of the cation, accounting for all these possibilities is not trivial. To make the number of calculations more tractable, most studies focus on a few active sites. We attempt to go beyond these limitations by implementing a workflow for a high throughput screening, designed to systematize the problem and exhaustively search for feasible active sites. We use Pd-exchanged CHA and BEA to illustrate the approach. After conducting thousands of individual calculations, we identify the sites most favorable for the Pd cation and discuss the results in detail. The high throughput screening identifies many energetically favorable sites that are non-trivial. Lastly, we employ these results to examine NO adsorption in Pd-exchanged CHA, which is a promising passive NOx adsorbent (PNA) during the cold start of automobiles. The results shed light on critical active sites for NOx capture that were not previously studied.

Machine learning-based high throughput screening for nitrogen fixation on boron-doped single atom catalysts

2020 ◽  
Vol 8 (10) ◽  
pp. 5209-5216 ◽  
Author(s):  
Mohammad Zafari ◽  
Deepak Kumar ◽  
Muhammad Umer ◽  
Kwang S. Kim
Keyword(s):  
Machine Learning ◽  
Nitrogen Fixation ◽  
High Throughput ◽  
High Throughput Screening ◽  
Reduction Reaction ◽  
Single Atom ◽  
Nitrogen Reduction ◽  
Computational Burden ◽  
Boron Doped

Machine learning (ML) methods would significantly reduce the computational burden of catalysts screening for nitrogen reduction reaction (NRR).

scholarly journals Preparation of Metal Oxides Containing ppm Levels of Pd as Catalysts for the Reduction of Nitroarene and Evaluation of Their Catalytic Activity by the Fluorescence-Based High-Throughput Screening Method

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 542
Author(s):  
Taeho Lim ◽  
Min Su Han
Keyword(s):  
Catalytic Activity ◽  
Metal Oxides ◽  
High Throughput ◽  
High Throughput Screening ◽  
Screening Method ◽  
Reduction Reaction ◽  
Precipitation Method ◽  
Reaction Conditions ◽  
One Pot ◽  
Co Precipitation

Herein, an easily accessible and efficient green method for the reduction of nitroarene compounds was developed using metal oxide catalysts. Heterogeneous metal oxides with or without Pd were prepared by a simple and scalable co-precipitation method and used for the reduction of nitroarenes. A fluorescence-based high-throughput screening (HTS) method was also developed for the rapid analysis of the reaction conditions. The catalytic activity of the metal oxides and reaction conditions were rapidly screened by the fluorescence-based HTS method, and Pd/CuO showed the highest catalytic activity under mild reaction conditions. After identifying the optimal reaction conditions, various nitroarenes were reduced to the corresponding aniline derivatives by Pd/CuO (0.005 mol% of Pd) under these conditions. Furthermore, the Pd/CuO catalyst was used for the one-pot Suzuki–Miyaura cross-coupling/reduction reaction. A gram-scale reaction (20 mmol) was successfully performed using the present method, and Pd/CuO showed high reusability without a loss of catalytic activity for five cycles.

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