scholarly journals Bio-inspired cofacial Fe porphyrin dimers for efficient electrocatalytic CO2 to CO conversion: Overpotential tuning by substituents at the porphyrin rings

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Zaki N. Zahran ◽  
Eman A. Mohamed ◽  
Yoshinori Naruta
Keyword(s):  
Co Conversion ◽  
Porphyrin Dimers ◽  
Porphyrin Rings

Excess Polarizability Reveals Exciton Localization/Delocalization Controlled by Linking Positions on Porphyrin Rings in Butadiyne-Bridged Porphyrin Dimers

2010 ◽  
Vol 114 (10) ◽  
pp. 3384-3390 ◽  
Author(s):  
Chunxing She ◽  
Shanmugam Easwaramoorthi ◽  
Pyosang Kim ◽  
Satoru Hiroto ◽  
Ichiro Hisaki ◽  
...  
Keyword(s):  
Exciton Localization ◽  
Porphyrin Dimers ◽  
Porphyrin Rings

Highly efficient and selective photocatalytic CO2 to CO conversion in aqueous solution

2020 ◽  
Vol 56 (27) ◽  
pp. 3851-3854 ◽  
Author(s):  
Xiaomin Chai ◽  
Hai-Hua Huang ◽  
Huiping Liu ◽  
Zhuofeng Ke ◽  
Wen-Wen Yong ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Performance ◽  
Aqueous Media ◽  
Highly Efficient ◽  
Co Conversion

A Co-based complex displayed the highest photocatalytic performance for CO2 to CO conversion in aqueous media.

Biology of Heme: Drug Interactions and Adverse Drug Reactions with CYP450

2019 ◽  
Vol 18 (23) ◽  
pp. 2042-2055 ◽  
Author(s):  
Neeraj Kumar ◽  
Heerak Chugh ◽  
Damini Sood ◽  
Snigdha Singh ◽  
Aarushi Singh ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Drug Metabolism ◽  
Drug Interactions ◽  
Adverse Drug Reactions ◽  
Genetic Defects ◽  
Drug Reactions ◽  
Detailed Structure ◽  
Synthesis And Degradation ◽  
Porphyrin Rings

Heme is central to functions of many biologically important enzymes (hemoproteins). It is an assembly of four porphyrin rings joined through methylene bridges with a central Fe (II). Heme is present in all cells, and its synthesis and degradation balance its amount in the cell. The deregulations of heme networks and incorporation in hemoproteins lead to pathogenic state. This article addresses the detailed structure, biosynthesis, degradation, and transportation associated afflictions to heme. The article is followed by its roles in various diseased conditions where it is produced mainly as the cause of increased hemolysis. It manifests the symptoms in diseases as it is a pro-oxidant, pro-inflammatory and pro-hemolytic agent. We have also discussed the genetic defects that tampered with the biosynthesis, degradation, and transportation of heme. In addition, a brief about the largest hemoprotein group of enzymes- Cytochrome P450 (CYP450) has been discussed with its roles in drug metabolism.

scholarly journals Investigation of Co–Fe–Al Catalysts for High-Calorific Synthetic Natural Gas Production: Pilot-Scale Synthesis of Catalysts

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 105
Author(s):  
Tae Young Kim ◽  
Seong Bin Jo ◽  
Jin Hyeok Woo ◽  
Jong Heon Lee ◽  
Ragupathy Dhanusuraman ◽  
...  
Keyword(s):  
Natural Gas ◽  
Spinel Phase ◽  
Space Velocity ◽  
Pilot Scale ◽  
Gas Production ◽  
Laboratory Scale ◽  
Optimum Conditions ◽  
Synthetic Natural Gas ◽  
Co Conversion ◽  
Ft Ir

Co–Fe–Al catalysts prepared using coprecipitation at laboratory scale were investigated and extended to pilot scale for high-calorific synthetic natural gas. The Co–Fe–Al catalysts with different metal loadings were analyzed using BET, XRD, H2-TPR, and FT-IR. An increase in the metal loading of the Co–Fe–Al catalysts showed low spinel phase ratio, leading to an improvement in reducibility. Among the catalysts, 40CFAl catalyst prepared at laboratory scale afforded the highest C2–C4 hydrocarbon time yield, and this catalyst was successfully reproduced at the pilot scale. The pelletized catalyst prepared at pilot scale showed high CO conversion (87.6%), high light hydrocarbon selectivity (CH4 59.3% and C2–C4 18.8%), and low byproduct amounts (C5+: 4.1% and CO2: 17.8%) under optimum conditions (space velocity: 4000 mL/g/h, 350 °C, and 20 bar).

scholarly journals Preparation and High-Throughput Testing of TiO2-Supported Co Catalysts for Fischer‒Tropsch Synthesis

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 352
Author(s):  
Christian Schulz ◽  
Peter Kolb ◽  
Dennis Krupp ◽  
Lars Ritter ◽  
Alfred Haas ◽  
...  
Keyword(s):  
High Throughput ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Tropsch Synthesis ◽  
Performance Tests ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Co Catalysts ◽  
Impregnation Technique ◽  
Co Conversion

A series of Co/TiO2 catalysts was tested in a parameters field study for Fischer‒Tropsch synthesis (FTS). All catalysts were prepared by the conventional impregnation technique to obtain an industrially relevant Co content of 10 wt % or 20 wt %, respectively. In summary, 10 different TiO2 of pure anatase phase, pure rutile phase, as well as mixed rutile and anatase phase were used as supports. Performance tests were conducted with a 32-fold high-throughput setup for accelerated catalyst benchmarking; thus, 48 experiments were completed within five weeks in a relevant operation parameters field (170 °C to 233.5 °C, H2/CO ratio 1 to 2.5, and 20 bar(g)). The most promising catalyst showed a CH4 selectivity of 5.3% at a relevant CO conversion of 60% and a C5+ productivity of 2.1 gC5+/(gCo h) at 207.5 °C. These TiO2-based materials were clearly differentiated with respect to the application as supports in Co-catalyzed FTS catalysis. The most prospective candidates are available for further FTS optimization at a commercial scale.

scholarly journals Facile Preparation of Mesoporous MCM-48 Containing Silver Nanoparticles with Fly Ash as Raw Materials for CO Catalytic Oxidation

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 841
Author(s):  
Dong Tian ◽  
Yonghong Chen ◽  
Xiaoyong Lu ◽  
Yihan Ling ◽  
Bin Lin
Keyword(s):  
Silver Nanoparticles ◽  
Fly Ash ◽  
Co Oxidation ◽  
Surface Composition ◽  
Raw Materials ◽  
Silica Source ◽  
Co Conversion ◽  
Co Catalytic Oxidation ◽  
Adsorption Desorption

An environmentally friendly method was proposed to prepare mesoporous Mobil Composition of Matter No.48 (MCM-48) using fly ash as the silica source. Silver nanoparticles were infiltrated on MCM-48 facilely by an in situ post-reduction method and evaluated as an effective catalyst for CO oxidation. The as-prepared MCM-48 and Ag/MCM-48 nanoparticles were characterized by XRD, N2 adsorption/desorption, and TEM. Investigations by means of XPS for Ag/MCM-48 were performed in order to illuminate the surface composition of the samples. Studies revealed the strong influence of the loading of Ag nanoparticles on catalysts in the oxidation of CO. CO conversion values for Ag/MCM-48 of 10% and 100% were achieved at temperatures of 220 °C and 270 °C, respectively, indicating that the Ag-decorated MCM-48 catalyst is extremely active for CO oxidation.

Synergistic co-conversion of pentane and methanol to aromatics over bifunctional metal/ZSM-5 zeolite catalysts

2021 ◽  
pp. 111107
Author(s):  
Xiaolin Zhu ◽  
Yue Wang ◽  
Guowei Wang ◽  
Yangfei Hou ◽  
Mingxuan Yu ◽  
...  
Keyword(s):  
Zeolite Catalysts ◽  
Co Conversion

scholarly journals Adventures in molecular recognition. The ins and outs of templating

2000 ◽  
Vol 72 (12) ◽  
pp. 2265-2274 ◽  
Author(s):  
Jeremy K. M. Sanders
Keyword(s):  
Molecular Recognition ◽  
Combinatorial Chemistry ◽  
Biological Systems ◽  
Design Approach ◽  
Supramolecular Systems ◽  
Disulfide Exchange ◽  
Dynamic Combinatorial Chemistry ◽  
Evolutionary Features ◽  
Selection Approach ◽  
Porphyrin Dimers

Two different approaches are described for the creation of supramolecular systems potentially capable of recognition and catalysis. Using the design approach, we have been able to accelerate and influence two different Diels­Alder reactions within the cavities of porphyrin dimers and trimers; this is templating from the outside inwards. The selection approach is a synthetic chemical attempt to capture some of the key evolutionary features of biological systems: dynamic combinatorial chemistry is used to create equilibrating mixtures of potential receptors, and then a template is used to select and amplify the desired system. Five potential reactions for such dynamic chemistry are discussed: base-catalyzed transesterification, hydrazone exchange, disulfide exchange, alkene metathesis, and Pd-catalyzed allyl exchange, and preliminary templating results (inside outwards) are presented.

scholarly journals Passivation of Co/Al2O3 Catalyst by Atomic Layer Deposition to Reduce Deactivation in the Fischer–Tropsch Synthesis

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 732
Author(s):  
José Antonio Díaz-López ◽  
Jordi Guilera ◽  
Martí Biset-Peiró ◽  
Dan Enache ◽  
Gordon Kelly ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Tropsch Synthesis ◽  
Catalyst Stability ◽  
Fischer Tropsch ◽  
Technical Feasibility ◽  
Fischer Tropsch Synthesis ◽  
Layer Deposition ◽  
Co Conversion ◽  
Al2o3 Catalyst

The present work explores the technical feasibility of passivating a Co/γ-Al2O3 catalyst by atomic layer deposition (ALD) to reduce deactivation rate during Fischer–Tropsch synthesis (FTS). Three samples of the reference catalyst were passivated using different numbers of ALD cycles (3, 6 and 10). Characterization results revealed that a shell of the passivating agent (Al2O3) grew around catalyst particles. This shell did not affect the properties of passivated samples below 10 cycles, in which catalyst reduction was hindered. Catalytic tests at 50% CO conversion evidenced that 3 and 6 ALD cycles increased catalyst stability without significantly affecting the catalytic performance, whereas 10 cycles caused blockage of the active phase that led to a strong decrease of catalytic activity. Catalyst deactivation modelling and tests at 60% CO conversion served to conclude that 3 to 6 ALD cycles reduced Co/γ-Al2O3 deactivation, so that the technical feasibility of this technique was proven in FTS.

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