Effect of Iterative Use of Methylcyclohexane as a Hydrogen Carrier on Catalytic Activity and By-product Formation

Hydrous hydrazine (N2H4∙H2O) is a candidate for a hydrogen carrier for storage and transportation due to low material cost, high hydrogen content of 8.0%, and liquid stability at room temperature. Pt and Pt nanoalloy catalysts have been welcomed by researchers for the dehydrogenation of hydrous hydrazine recently. Therefore, in this review, we give a summary of Pt nanoalloy catalysts for the dehydrogenation of hydrous hydrazine and briefly introduce the decomposition mechanism of hydrous hydrazine to prove the design principle of the catalyst. The chemical characteristics of hydrous hydrazine and the mechanism of dehydrogenation reaction are briefly introduced. The catalytic activity of hydrous hydrazine on different supports and the factors affecting the selectivity of hydrogen catalyzed by Ni-Pt are analyzed. It is expected to provide a new way for the development of high-activity catalysts for the dehydrogenation of hydrous hydrazine to produce hydrogen.

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Influence of the nanoparticle size on hydrogen release and side product formation in liquid organic hydrogen carrier systems with supported platinum catalysts

Catalysis Science & Technology ◽

10.1039/d0cy01173h ◽

2020 ◽

Vol 10 (19) ◽

pp. 6669-6678

Author(s):

Franziska Auer ◽

Alexander Hupfer ◽

Andreas Bösmann ◽

Normen Szesni ◽

Peter Wasserscheidpeter

Keyword(s):

Product Formation ◽

Hydrogen Release ◽

Nanoparticle Size ◽

Pt Catalyst ◽

Supported Platinum ◽

Supported Platinum Catalysts ◽

Hydrogen Carrier ◽

The Mean ◽

Carrier Systems ◽

Supported Pt Catalyst

The performance of an alumina supported Pt catalyst in the hydrogen release from perhydro-dibenzyltoluene is strongly depending on the mean Pt nanoparticle size.

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Engineering of a fungal nitrilase for improving catalytic activity and reducing by-product formation in the absence of structural information

Catalysis Science & Technology ◽

10.1039/c5cy01535a ◽

2016 ◽

Vol 6 (12) ◽

pp. 4134-4141 ◽

Cited By ~ 5

Author(s):

Jin-Song Gong ◽

Heng Li ◽

Zhen-Ming Lu ◽

Xiao-Juan Zhang ◽

Qiang Zhang ◽

...

Keyword(s):

Catalytic Activity ◽

Structural Information ◽

Product Formation ◽

Rational Engineering ◽

Engineering Approach

Semi-rational engineering approach was employed to improve the catalytic activity and reduce the by-product formation of fungal nitrilase.

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Investigation of axial ligand effects on catalytic activity of manganese porphyrin, evidence for the importance of hydrogen bonding in cytochrome-P450 model reactions

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424614500102 ◽

2014 ◽

Vol 18 (05) ◽

pp. 354-365 ◽

Cited By ~ 10

Author(s):

Elnaz Mesbahi ◽

Nasser Safari ◽

Mahin Gheidi

Keyword(s):

Hydrogen Bonding ◽

Catalytic Activity ◽

Product Formation ◽

Axial Ligand ◽

Active Species ◽

Manganese Porphyrin ◽

Axial Ligands ◽

Epoxidation Reaction ◽

Phenyl Rings ◽

Hydroxy Groups

Various nitrogenous bases, such as imidazoles, pyridines and amines were employed as axial ligands in epoxidation reaction of cyclooctene bytetra-n-butylammonium hydrogen monopersulfate (n- Bu 4 NHSO 5), in the presence of Mn ( III )-tetrakis(2,3-dimethoxyphenyl)porphyrin-acetate ( T (2,3- OMeP ) PorMnOAc ). T (2,3- OMeP ) PorMnOAc is a fairly stable catalyst, with the ability of producing hydrogen bonding. High epoxidation yield of 85 ± 6% was obtained in the presence of imidazole axial ligand with 100% selectivity in 30 min. Higher conversion of around 100% was obtained by pyridine axial base, while selectivity was reduced to 69%. Further epoxidation reactions were also performed using Mn ( III )-Tetrakis(2,3-dihydroxyphenyl)porphyrin-acetate ( T (2,3- OHP ) PorMnOAc ) as catalyst. In addition to the usual electronic and steric effects, it is proposed that the catalytic activity depends on the existence and kind of hydrogen bonding between the axial base and the ortho-methoxy or hydroxy groups on the phenyl rings of manganese porphyrin. The cis to trans ratio of cis-stilbene oxide formed by imidazole and pyridine axial bases were obtained as 7.5 and 2.5 respectively. In addition GC-Ms and UV-vis studies were employed to find the nature of active species and product formation. Our DFT calculations disclosed that pyridine hydrogen bonding with moiety of the macrocycle rings strongly affects the relative energies of S/Q spin states in [ T (2,3- OMeP ) PorMn V ( O )( Py )]+, in that it results in the longer Mn – O bond and reactivity toward substrates.

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Boosting the activity of hydrogen release from liquid organic hydrogen carrier systems by sulfur-additives to Pt on alumina catalysts

Catalysis Science & Technology ◽

10.1039/c9cy00817a ◽

2019 ◽

Vol 9 (13) ◽

pp. 3537-3547 ◽

Cited By ~ 12

Author(s):

Franziska Auer ◽

Dominik Blaumeiser ◽

Tanja Bauer ◽

Andreas Bösmann ◽

Normen Szesni ◽

...

Keyword(s):

Hydrogen Storage ◽

Product Formation ◽

Side Product ◽

Hydrogen Release ◽

Hydrogen Carrier ◽

Carrier Systems ◽

Interesting Alternative ◽

Alumina Catalysts

Liquid organic hydrogen carriers represent an interesting alternative for hydrogen storage and transport. We demonstrate a method to simultaneously increase the activity of LOHC dehydrogenation catalysts and reduce side product formation.

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The Role of Support in Formic Acid Decomposition on Gold Catalysts

Energies ◽

10.3390/en12214198 ◽

2019 ◽

Vol 12 (21) ◽

pp. 4198 ◽

Cited By ~ 2

Author(s):

Vladimir Sobolev ◽

Igor Asanov ◽

Konstantin Koltunov

Keyword(s):

Gold Nanoparticles ◽

Catalytic Activity ◽

Formic Acid ◽

Gas Flow ◽

Catalyst Support ◽

Gold Catalysts ◽

Packed Bed ◽

Packed Bed Reactor ◽

Hydrogen Carrier ◽

Supported Gold Nanoparticles

Formic acid (FA) can easily be decomposed, affording molecular hydrogen through a controllable catalytic process, thus attaining great importance as a convenient hydrogen carrier for hydrogen energetics. Supported gold nanoparticles are considered to be among the most promising catalysts for such applications. However, questions remain regarding the influence of the catalyst support on the reaction selectivity. In this study, we have examined the catalytic activity of typical gold catalysts, such as Au/TiO2, Au/SiO2, and Au/Al2O3 in decomposition of FA, and then compared it with the catalytic activity of corresponding supports. The performance of each catalyst and support was evaluated using a gas-flow packed-bed reactor. It is shown that the target reaction, FA → H2 + CO2, is provided by the presence of gold nanoparticles, whereas the concurrent, undesirable pathway, such as FA → H2O + CO, results exclusively from the acid-base behavior of supports.

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A Combined Spectroscopic and Molecular Modeling Study on Structure-Function-Dynamics under Chemical Modification: Alpha-Chymotrypsin with Formalin Preservative

10.1101/2021.07.24.453635 ◽

2021 ◽

Author(s):

Pritam Biswas ◽

Aniruddha Adhikari ◽

Uttam Pal ◽

Susmita Mondal ◽

Dipanjan Mukherjee ◽

...

Keyword(s):

Catalytic Activity ◽

Molecular Docking ◽

Amino Acid ◽

Large Scale ◽

Docking Study ◽

Product Formation ◽

Amino Acid Residues ◽

Acid Modification ◽

Molecular Docking Study ◽

Ans Binding

Enzyme conformations can be altered via modification of its amino acid residues, side chains and large-scale domain modifications, which are closely linked to its function. Herein, we have addressed the role of residue modification in catalytic activity and molecular recognition of an enzyme alpha-chymotrypsin (CHT) in presence of covalent cross-linker formalin. Optical spectroscopy studies exhibit reduced catalytic activity of the enzyme with increased formalin concentration. Polarization gated anisotropy studies of a fluorophore 8-anilino-1-napthelenesulfonic acid (ANS) in CHT show a dip rise pattern in presence of formalin which is consistent with the generation of multiple ANS binding sites in the enzyme owing to modifications of its local amino acid residues. Molecular docking study on minimal local residue modifications in CHT reveals formation of a stable enzyme-substrate complex even with the serine-histidine cross-linked enzyme which prohibits product formation giving rise to reduced catalytic activity. Keywords: amino acid modification; chymotrypsin; formalin; cross-linking; spectroscopy; molecular docking

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High resolution electron microscopy of lanthanum phosphate crystals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100108519 ◽

1978 ◽

Vol 36 (1) ◽

pp. 274-275

Author(s):

J. C. Wheatley ◽

J. M. Cowley

Keyword(s):

Electron Microscopy ◽

Catalytic Activity ◽

High Resolution ◽

Petroleum Industry ◽

High Resolution Electron Microscopy ◽

Lanthanum Phosphate ◽

Good Catalyst ◽

Resolution Electron ◽

Good Catalytic Activity ◽

Physical And Chemical

Rare-earth phosphates are of particular interest because of their catalytic properties associated with the hydrolysis of many aromatic chlorides in the petroleum industry. Lanthanum phosphates (LaPO4) which have been doped with small amounts of copper have shown increased catalytic activity (1). However the physical and chemical characteristics of the samples leading to good catalytic activity are not known.Many catalysts are amorphous and thus do not easily lend themselves to methods of investigation which would include electron microscopy. However, the LaPO4, crystals are quite suitable samples for high resolution techniques.The samples used were obtained from William L. Kehl of Gulf Research and Development Company. The electron microscopy was carried out on a JEOL JEM-100B which had been modified for high resolution microscopy (2). Standard high resolution techniques were employed. Three different sample types were observed: 669A-1-5-7 (poor catalyst), H-L-2 (good catalyst) and 27-011 (good catalyst).

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