scholarly journals Why does the Conductivity of a Nickel Catalyst Increase during Sulfidation? An Exemplary Study Using an In Operando Sensor Device

Sensors ◽  
2015 ◽  
Vol 15 (10) ◽  
pp. 27021-27034 ◽  
Author(s):  
Peter Fremerey ◽  
Andreas Jess ◽  
Ralf Moos
2020 ◽  
Author(s):  
Xinkai Qiu ◽  
Sylvia Rousseva ◽  
Gang Ye ◽  
Jan C. Hummelen ◽  
Ryan Chiechi

This paper describes the reconfiguration of molecular tunneling junctions during operation via the self-assembly of bilayers of glycol ethers. We use well-established functional groups to modulate the magnitude and direction of rectification in assembled tunneling junctions by exposing them to solutions containing different glycol ethers. Variable-temperature measurements establish that rectification occurs by a bias-dependent tunneling-hopping mechanism and that glycol ethers, beside being an unusually efficient tunneling medium, behave identically to alkanes. We fabricated memory bits from crossbar junctions prepared by injecting eutectic Ga-In into microfluidic channels. Two 8-bit registers were able to perform logical AND operations on bit strings encoded into chemical packets as microfluidic droplets that alter the composition of the crossbar junctions through self-assembly to effect memristor-like properties. This proof of concept work demonstrates the potential for fieldable molecular-electronic devices based on tunneling junctions of self-assembled monolayers and bilayers.


1982 ◽  
Vol 47 (12) ◽  
pp. 3230-3235 ◽  
Author(s):  
Olga Marholová ◽  
Karel Smrček

A hydrophobic porous hydrogen anode was prepared whose electrochemical parameters are comparable with anodes containing a platinum catalyst. For its successful preparation, oxidation of the Raney nickel catalyst with air oxygen or with fluorine from Teflon must be prevented. The electrodes of a geometric surface area up to 450 cm2 were tested in cells and modules filled with 7M-KOH.


1998 ◽  
Vol 63 (11) ◽  
pp. 1945-1953 ◽  
Author(s):  
Jiří Hanika ◽  
Karel Sporka ◽  
Petr Macoun ◽  
Vladimír Kysilka

The activity of ruthenium, palladium, and nickel catalysts for the hydrogenation of 1,2-dihydroacenaphthylene in cyclohexane solution was studied at temperatures up to 180 °C and pressures up to 8 MPa. The GC-MS technique was used to identify most of the perhydroacenaphthylene stereoisomers, whose fractions in the product were found dependent on the nature of the active component of the catalyst. The hydrogenation was fastest on the palladium catalyst (3% Pd/C). The nickel catalyst Ni-NiO/Al2O3, which is sufficiently active also after repeated use, can be recommended for practical application. The activation energy of 1,2-dihydroacenaphthylene hydrogenation using this catalyst is 17 kJ/mol, the reaction order with respect to hydrogen is unity.


Science ◽  
2021 ◽  
Vol 372 (6538) ◽  
pp. 175-182
Author(s):  
Hairong Lyu ◽  
Ilia Kevlishvili ◽  
Xuan Yu ◽  
Peng Liu ◽  
Guangbin Dong

Mild methods to cleave the carbon-oxygen (C−O) bond in alkyl ethers could simplify chemical syntheses through the elaboration of these robust, readily available precursors. Here we report that dibromoboranes react with alkyl ethers in the presence of a nickel catalyst and zinc reductant to insert boron into the C−O bond. Subsequent reactivity can effect oxygen-to-nitrogen substitution or one-carbon homologation of cyclic ethers and more broadly streamline preparation of bioactive compounds. Mechanistic studies reveal a cleavage-then-rebound pathway via zinc/nickel tandem catalysis.


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Christoph Lenting ◽  
Thorsten Geisler

AbstractFluid-cell Raman spectroscopy is a space and time-resolving application allowing in operando studies of dynamic processes during solution–solid interactions. A currently heavily debated example is the corrosion mechanism of borosilicate glasses, which are the favoured material for the immobilization of high-level nuclear waste. With an upgraded fluid-cell lid design made entirely from the glass sample itself, we present the polymerization of the surface alteration layer over time in an initially acidic environment, including the differentiation between pore and surface-adsorbed water within it. Our results support an interface-coupled dissolution-precipitation model, which opposes traditional ion-exchange models for the corrosion mechanism. A sound description of the corrosion mechanism is essential for reliable numerical models to predict the corrosion rate of nuclear waste glasses during long-term storage in a geological repository.


Author(s):  
Yejin Yang ◽  
Jeongwon Kim ◽  
Hyoi Jo ◽  
Arim Seong ◽  
Minzae Lee ◽  
...  

Ammonia has emerged as attractive liquid fuel for hydrogen production owing to its facile transportation, high capacity of hydrogen storage, and ecofriendly environmental products (N2 and H2). Moreover, the electrolysis...


Author(s):  
Lunlun Gong ◽  
Peili Zhang ◽  
Guoquan Liu ◽  
Yu Shan ◽  
Mei Wang

Modification of the surface of semiconductor-based photoelectrodes with molecular redox catalysts gives a way to realize atom-efficient catalysis for photoelectrochemical (PEC) H2 and O2 evolution. However, the diversity of immobilized...


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