CO2-based hydrogen storage: CO2 hydrogenation to formic acid, formaldehyde and methanol

2018 ◽  
Vol 3 (3) ◽  
Author(s):  
Thomas Schaub
Keyword(s):  
Hydrogen Storage ◽  
Formic Acid ◽  
Mobile Applications ◽  
Organic Molecules ◽  
State Of The Art ◽  
Co2 Hydrogenation ◽  
The State ◽  
Reverse Reaction ◽  
Small Organic Molecules ◽  
Hydrogenation Of Co

AbstractThe storage of hydrogen via hydrogenation of CO2to small organic molecules can be attractive for mobile applications. In this article, the state of the art regarding hydrogen storage in Methanol, Formic Acid as well as Formaldehyde and derivates based on CO2hydrogenation is summarized. The reverse reaction, the release of hydrogen from these molecules is also crucial and described in the articles together with possible concepts for the use of hydrogen storage by CO2hydrogenation.

Usability Heuristics for Mobile Phone Applications

2015 ◽  
pp. 143-157 ◽  
Author(s):  
Thaísa C. Lacerda ◽  
Juliane V. Nunes ◽  
Christiane Gresse von Wangenheim
Keyword(s):  
Literature Review ◽  
Mobile Phone ◽  
Mobile Phones ◽  
Systematic Literature Review ◽  
Mobile Applications ◽  
State Of The Art ◽  
The State ◽  
Computer Applications ◽  
Starting Point ◽  
Mobile Phone Applications

In this chapter, we discuss the importance of evaluating the usability of mobile applications using tools and technics that consider their specific characteristics. One common way to evaluate usability is using heuristics. However, since many assumptions regarding usability of computer applications are not true for mobile applications, a question arises: does there exist usability heuristics specific for this type of device? To answer this question, we conducted a systematic literature review. We mapped the encountered sets of heuristics to Nielsen's ten heuristics and identified additional ones specifically proposed for this kind of device. Our review indicates that research with respect to usability heuristics for mobile phones are still sparse. Nevertheless, this chapter provides an overview on the state of the art that can guide the design and evaluation of interfaces for mobile applications as well as provide a starting point for the evolution of such customized heuristics.

scholarly journals Energy storage applications of activated carbons: supercapacitors and hydrogen storage

2014 ◽  
Vol 7 (4) ◽  
pp. 1250-1280 ◽  
Author(s):  
Marta Sevilla ◽  
Robert Mokaya
Keyword(s):  
Energy Storage ◽  
Hydrogen Storage ◽  
Electrode Materials ◽  
Activated Carbons ◽  
State Of The Art ◽  
The State ◽  
Hydrogen Storage Materials ◽  
Storage Materials ◽  
Energy Storage Applications

This review presents the state-of-the-art with respect to synthesis of activated carbons, and their use as electrode materials in supercapacitors and as hydrogen storage materials.

scholarly journals Electrocatalytic Efficiency of the Oxidation of Ethylene glycol, Glycerol, and Glucose under Oscillatory Regime

2021 ◽  
Author(s):  
Gabriel Melle ◽  
Thiago Altair ◽  
Rafael Romano ◽  
Hamilton Varela
Keyword(s):  
Ethylene Glycol ◽  
Formic Acid ◽  
Organic Molecules ◽  
Electrical Energy ◽  
Oscillatory Regime ◽  
Experimental Conditions ◽  
Small Organic Molecules ◽  
Self Organized ◽  
Polycrystalline Platinum ◽  
Surface Poisoning

There is an increasingly interest in the use of small organic molecules in the interconversion between chemical and electrical energies. Among the strategies to improve the processes of yielding electrical energy in fuel cells and the production of clear hydrogen in electrochemical reform is the use of kinetic instabilities to improve the conversion and selectivity. Herein we report on the electrocatalytic efficiency of the oxidation of ethylene glycol, glycerol, and glucose, under regular and oscillatory regimes, on polycrystalline platinum, in sulfuric acid aqueous solution, and at 25 oC. Despite the high overpotentials for the electro-oxidation of these molecules, the electrochemical activity along quasi-stationary potentio/gavanostatic experiments evidenced that, in all cases, relatively lower potential values, and thus higher activity, are reached during oscillations. Noticeably higher power densities for the electrooxidation of ethylene glycol and glycerol under oscillatory regime in a hypothetical direct liquid fuel cell. The use of identical experimental conditions of that of our previous study[J. Phys. Chem. C 120 (2016) 22365] allowed at discussing some universal trends for seven small organic molecules. We compile the results in terms of the peak current, the maximum poisoning rate found along the oscillations, and the oscillation frequency. The three parameters were found to decrease in the order: formaldehyde > formic acid > methanol > ethanol > ethylene glycol > glycerol > glucose. In addition, we discussed the increase of the voltammetric current with the self-organized poisoning rate and reinforce the trend that high electrocatalytic activity implies high susceptibility to surface poisoning for this set of species. Finally, the analysis done for all species (formic acid, formaldehyde, methanol, ethylene glycol, ethanol, glycerol, and glucose) adds to the available thermodynamic data and is a benchmark against which the activities under oscillatory regime at 25 oC may be compared or assessed. This point of reference permits to explore further experimental conditions that are relevant for energy-related devices, including the conversion of chemical into electrical energy and the electrochemical reform to produce clean hydrogen in electrolyzers.

scholarly journals On the electro-oxidation of small organic molecules: towards a fuel cell catalyst testing platform

2021 ◽  
Author(s):  
Damin Zhang ◽  
Jia Du ◽  
Jonathan Quinson ◽  
Matthias Arenz
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Formic Acid ◽  
Organic Molecules ◽  
Gas Diffusion ◽  
Gas Diffusion Electrode ◽  
Proton Exchange ◽  
Electrochemical Cells ◽  
Small Organic Molecules ◽  
Electro Oxidation

The electrocatalytic oxidation of small organic compounds such as methanol or formic acid has been the subject of numerous investigations in the last decades. The motivation for these studies is often their use as fuel in so-called direct methanol or direct formic acid fuel cells, promising alternatives to hydrogen-fueled proton exchange membrane fuel cells. The fundamental research spans from screening studies to identify the best performing catalyst materials to detailed mechanistic investigations of the reaction pathway. These investigations are commonly performed in standard three electrode electrochemical cells with a liquid supporting electrolyte to which the methanol or formic acid is added. In fuel cell devices, however, no liquid electrolyte will be present, instead membrane electrolytes are used. The question therefore arises, to which extend results from conventional electrochemical cells can be extrapolated to conditions found in fuel cells. We previously developed a gas diffusion electrode setup to mimic “real-life” reaction conditions and study electrocatalysts for oxygen gas reduction or water splitting. It is here demonstrated that the setup is also suitable to investigate the properties of catalysts for the electro-oxidation of small organic molecules. Using the gas diffusion electrode setup, it is seen that employing a catalyst - membrane electrolyte interface as compared to conventional electrochemical cells can lead to significantly different catalyst performances. Therefore, it is recommended to implement gas diffusion electrode setups for the investigation of the electro-oxidation of small organic molecules.

scholarly journals Ferroelectric columnar assemblies from the bowl-to-bowl inversion of aromatic cores

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shunsuke Furukawa ◽  
Jianyun Wu ◽  
Masaya Koyama ◽  
Keisuke Hayashi ◽  
Norihisa Hoshino ◽  
...  
Keyword(s):  
Organic Compounds ◽  
Organic Molecule ◽  
Remanent Polarization ◽  
Organic Molecules ◽  
Materials Science ◽  
State Of The Art ◽  
Condensed Matter ◽  
Small Organic Molecules ◽  
Organic Ferroelectrics ◽  
Potential Use

AbstractOrganic ferroelectrics, in which the constituent molecules retain remanent polarization, represent an important topic in condensed-matter science, and their attractive properties, which include lightness, flexibility, and non-toxicity, are of potential use in state-of-the-art ferroelectric devices. However, the mechanisms for the generation of ferroelectricity in such organic compounds remain limited to a few representative concepts, which has hitherto severely hampered progress in this area. Here, we demonstrate that a bowl-to-bowl inversion of a relatively small organic molecule with a bowl-shaped π-aromatic core generates ferroelectric dipole relaxation. The present results thus reveal an unprecedented concept to produce ferroelectricity in small organic molecules, which can be expected to strongly impact materials science.

scholarly journals Electrocatalytic Efficiency of the Oxidation of Ethylene glycol, Glycerol, and Glucose under Oscillatory Regime

2021 ◽  
Author(s):  
Gabriel Melle ◽  
Thiago Altair ◽  
Rafael Romano ◽  
Hamilton Varela
Keyword(s):  
Ethylene Glycol ◽  
Formic Acid ◽  
Organic Molecules ◽  
Electrical Energy ◽  
Oscillatory Regime ◽  
Experimental Conditions ◽  
Small Organic Molecules ◽  
Self Organized ◽  
Polycrystalline Platinum ◽  
Surface Poisoning

There is an increasingly interest in the use of small organic molecules in the interconversion between chemical and electrical energies. Among the strategies to improve the processes of yielding electrical energy in fuel cells and the production of clear hydrogen in electrochemical reform is the use of kinetic instabilities to improve the conversion and selectivity. Herein we report on the electrocatalytic efficiency of the oxidation of ethylene glycol, glycerol, and glucose, under regular and oscillatory regimes, on polycrystalline platinum, in sulfuric acid aqueous solution, and at 25 oC. Despite the high overpotentials for the electro-oxidation of these molecules, the electrochemical activity along quasi-stationary potentio/gavanostatic experiments evidenced that, in all cases, relatively lower potential values, and thus higher activity, are reached during oscillations. Noticeably higher power densities for the electrooxidation of ethylene glycol and glycerol under oscillatory regime in a hypothetical direct liquid fuel cell. The use of identical experimental conditions of that of our previous study[J. Phys. Chem. C 120 (2016) 22365] allowed at discussing some universal trends for seven small organic molecules. We compile the results in terms of the peak current, the maximum poisoning rate found along the oscillations, and the oscillation frequency. The three parameters were found to decrease in the order: formaldehyde > formic acid > methanol > ethanol > ethylene glycol > glycerol > glucose. In addition, we discussed the increase of the voltammetric current with the self-organized poisoning rate and reinforce the trend that high electrocatalytic activity implies high susceptibility to surface poisoning for this set of species. Finally, the analysis done for all species (formic acid, formaldehyde, methanol, ethylene glycol, ethanol, glycerol, and glucose) adds to the available thermodynamic data and is a benchmark against which the activities under oscillatory regime at 25 oC may be compared or assessed. This point of reference permits to explore further experimental conditions that are relevant for energy-related devices, including the conversion of chemical into electrical energy and the electrochemical reform to produce clean hydrogen in electrolyzers.

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