Featured Research

from universities, journals, and other organizations

Electrochemical step towards a better hydrogen storage

Date:
August 14, 2013
Source:
Institute of Physical Chemistry of the Polish Academy of Sciences
Summary:
Good metal-based systems for hydrogen storage cannot be developed without knowing how this element permeates through metals. Researchers have managed to apply a user-friendly electrochemical method to study hydrogen diffusion in highly reactive metals.

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 Krzyżewski

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 (610^12) 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.


Story Source:

The above story is based on materials provided by Institute of Physical Chemistry of the Polish Academy of Sciences. Note: Materials may be edited for content and length.


Cite This Page:

Institute of Physical Chemistry of the Polish Academy of Sciences. "Electrochemical step towards a better hydrogen storage." ScienceDaily. ScienceDaily, 14 August 2013. <www.sciencedaily.com/releases/2013/08/130814100200.htm>.
Institute of Physical Chemistry of the Polish Academy of Sciences. (2013, August 14). Electrochemical step towards a better hydrogen storage. ScienceDaily. Retrieved July 27, 2014 from www.sciencedaily.com/releases/2013/08/130814100200.htm
Institute of Physical Chemistry of the Polish Academy of Sciences. "Electrochemical step towards a better hydrogen storage." ScienceDaily. www.sciencedaily.com/releases/2013/08/130814100200.htm (accessed July 27, 2014).

Share This




More Matter & Energy News

Sunday, July 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
Powered by NewsLook.com
Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com
Algonquin Power Goes Activist on Its Target Gas Natural

Algonquin Power Goes Activist on Its Target Gas Natural

TheStreet (July 23, 2014) When The Deal's Amanda Levin exclusively reported that Gas Natural had been talking to potential suitors, the Ohio company responded with a flat denial, claiming its board had not talked to anyone about a possible sale. Lo and behold, Canadian utility Algonquin Power and Utilities not only had approached the company, but it did it three times. Its last offer was for $13 per share as Gas Natural's was trading at a 60-day moving average of about $12.50 per share. Now Algonquin, which has a 4.9% stake in Gas Natural, has taken its case to shareholders, calling on them to back its proposals or, possibly, a change in the target's board. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins