Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. 24/7 Space News .




ENERGY TECH
Electrochemical step towards a better hydrogen storage
by Staff Writers
Warsaw, Poland (SPX) Aug 19, 2013


New membrane with multilayer structure allows -- in combination with appropriate measurement techniques -- for electrochemical studies on hydrogen permeation rate in reactive metals, including magnesium. The picture shows Dr Arkadiusz Gajek from the Institute of Physical Chemistry of the Polish Academy of Sciences in Warsaw. Credit: IPC PAS, Grzegorz Krzyzewski.

Good metal-based systems for hydrogen storage cannot be developed without knowing how this element permeates through metals. Researchers at the Institute of Physical Chemistry of the Polish Academy of Sciences in Warsaw managed to apply a user-friendly electrochemical method to study hydrogen diffusion in highly reactive metals.

Hydrogen is seen as a versatile energy carrier for the future. Unfortunately, the element practically does not occur in the free state on Earth. Therefore, it must be first generated (e.g., by electrolysis of water), then stored, to be finally used -- ideally in fuel cells transforming chemical energy directly into electrical one. Hydrogen storage represents, however, a serious challenge.

The drawbacks of conventional storage tanks for gaseous and liquid hydrogen force us to look for other solutions. One of the promising methods for hydrogen storage makes use of the capability of some metals and alloys to easily uptake this element. The development of efficient hydrogen storage systems requires, however, a detailed knowledge on how hydrogen diffuses in metals.

Hydrogen permeation through metals can be conveniently studied with electrochemical methods. These methods fail, however, for metals where the diffusion of hydrogen is relatively slow, and also in cases where metals strongly react with aqueous electrolyte solutions. The problem relates in particular to magnesium and magnesium alloys that are considered the most attractive materials for hydrogen storage.

"We managed to overcome this obstacle", says Prof. Tadeusz Zakroczymski, whose team at the Institute of Physical Chemistry of the Polish Academy of Sciences (IPC PAS) in Warsaw has been for many years carrying out comprehensive research on hydrogen permeation, diffusion and uptake in metals.

The information on how hydrogen diffuses in metals is usually obtained from electrochemical measurements of the rate of hydrogen permeation through a sample being usually a membrane separating two independent electrolytic cells. On one side the membrane is charged with hydrogen produced cathodically in an aqueous solution.

The electrochemical charging is simple and very efficient. "A relatively low cathode current density, in the range of miliamperes per square centimeter, can correspond to a pressure of gaseous hydrogen in the range of a few tens of thousands of atmospheres", explains Dr Arkadiusz Gajek (IPC PAS).

Hydrogen atoms enter the membrane, diffuse through it and subsequently leave the membrane on the other side. Here, due to appropriate conditions, they do not recombine but are immediately electrochemically oxidised to protons. This electrochemical detection of hydrogen is extremely sensitive. An easy-to-measure current density of one microampere per square centimeter corresponds a stream of about six trillion (6+ 10^12) single hydrogen atoms per second per square centimeter.

Prof. Zakroczymski's team constructed a membrane that allows to electrochemically insert hydrogen into highly reactive metals, and -- also electrochemically -- to detect it. The membrane has a multilayer structure. The main layer, a structural basis of the membrane, is made of iron.

This metal was selected because hydrogen atoms move exceptionally fast in iron crystal lattice: their rate of diffusion at room temperature is comparable to that of hydrogen ions in aqueous solutions. Therefore, the iron layer has a relatively small effect on the hydrogen permeation rate through the entire membrane.

Both sides of the iron membrane are coated electrochemically with a thin palladium film. Then they are coated with magnesium and (for protection purposes) again with palladium using PVD methods. Both elements were deposited in cooperation with Prof. Wen-Ta Tsai's laboratory from National Cheng Kung University in Tainan, Taiwan.

"The measured rate of hydrogen permeation through a multilayer membrane depends on hydrogen diffusion in each membrane layer. Because hydrogen diffusion in iron and palladium is a well studied process, the diffusion coefficient of hydrogen in the magnesium layer can be deduced if we know the thickness of each layer", explains Prof. Zakroczymski.

.


Related Links
Institute of Physical Chemistry of the Polish Academy of Sciences
Powering The World in the 21st Century at Energy-Daily.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





ENERGY TECH
Low-temperature combustion enables cleaner, more efficient engines
Livermore CA (SPX) Aug 21, 2013
As demand climbs for more fuel-efficient vehicles, knowledge compiled over several years about diesel engines and a new strategy known as "low-temperature combustion" (LTC) might soon lead auto manufacturers and consumers to broader use of cleaner diesel engines in the United States. The journal Progress in Energy and Combustion Science published a summary of recent research on diesel LTC ... read more


ENERGY TECH
NASA Prepares for First Virginia Coast Launch to Moon

NASA Selects Launch Services Contract for OSIRIS-REx Mission

Environmental Controls Move Beyond Earth

Bad night's sleep? The moon could be to blame

ENERGY TECH
International Space Agencies Outline Steps to Take Humans to Mars

Snapping Pictures of the Martian Moons

Mars Rover Opportunity Working at Edge of 'Solander'

MRO Swapping Motion-Sensing Units

ENERGY TECH
NSBRI and NASA Reduce Space Radiation Risks by Soliciting for Center of Space Radiation Research

Next Generation of Explorers Takes the Stage

Has Voyager 1 Left The Solar System?

Groundbreaking space exploration research at UH

ENERGY TECH
China launches three experimental satellites

Medical quarantine over for Shenzhou-10 astronauts

China's astronauts ready for longer missions

Chinese probe reaches record height in space travel

ENERGY TECH
Cosmonauts Complete Spacewalk, Unfold Russian Flag in Space

Italian astronaut recounts spacewalk drowning terror

ISS Boosting Biological Research in Orbit

Japanese Cargo Craft Captured, Berthed to ISS

ENERGY TECH
NASA Explores New Uses for Historic Launch Structures

Telemetry data confirms launch of South Korean satellite

ISRO pins hopes on GSLV-D5

Lockheed Martin Selects CubeSat Integrators for Athena to Enhance Launch Systems Integration

ENERGY TECH
Study: Planets might be 'born free' without a parent star

Distant planet sets speed record by orbiting its star every 8.5 hours

Kepler planet hunter spacecraft is beyond repair: NASA

Astronomers Image Lowest-mass Exoplanet Around a Sun-like Star

ENERGY TECH
U.S. firm releases $1,400 scanner to create 3-D printing files

Boeing Communications Relay Satellites Complete Space, Earthly Testing

Mobius strip ties liquid crystal in knots to produce tomorrow's materials and photonic devices

The world's future tallest skyscrapers: who will be first to break the 1,000-meter mark?




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement