Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Keeping the hydrogen coming

07.06.2017

A novel molybdenum-coated catalyst that can efficiently split water in acidic electrolytes is developed by researchers at KAUST and could help with efficient production of hydrogen.

When burned, hydrogen is converted into water and heat to make an entirely clean power source. Thus, in the quest for greener power, there is an urgent need for a sustainable and efficient means of producing it. One way is to split water using a process known as photocatalytic hydrogen evolution: water molecules are split into hydrogen and oxygen using only sunlight to provide the necessary energy. In this sense, hydrogen acts as a means of storing solar energy.


A high-resolution electron microscope image (right) of the platinum electrocatalytic layer coated with molybdenum. The platinum catalyzes the hydrogen-evolution reaction (left) in acidic medium from protons in the electrolyte while the molybdenum layer inhibits water-forming reactions.

Credit: © 2017 KAUST

Scientists are searching for ways of improving this water-splitting reaction by developing an optimal catalyst. While many different materials have been tried, they are usually adversely affected by the oxygen that is also created alongside the hydrogen during the process. The two gaseous products can easily recombine back to water due to reverse water-forming reactions, hindering the production of hydrogen.

Angel Garcia-Esparza and Tatsuya Shinagawa--two former KAUST Ph.D. students as leading researchers supervised by Associate Professor of Chemical Science Kazuhiro Takanabe--collaborated with other colleagues from the Catalysis Center and other specialists in the University to create a hydrogen-evolution reaction catalyst that is both acid-tolerant and selectively prevents the water-reforming reaction1.

"The development of acid-tolerant catalysts is an important challenge because most materials are not stable and quickly degrade in the acidic conditions that are favorable for hydrogen generation," says Garcia-Esparza.

Because the acidity of the solution was crucial for the stability of the material, the team took the time to establish the optimal pH level between 1.1 and 4.9. They then electro-coated molybdenum onto a standard platinum electrode catalyst in a mildly acidic solution.

Comparing the performance of the photocatalyst with and without the molybdenum coating, the team showed that without molybdenum the rate of hydrogen production eventually plateaued after 10 hours of operation under illumination by ultraviolet light. However, the introduction of molybdenum prevented this fall in performance. The researchers believe that this is because the molybdenum acts as a gas membrane, preventing oxygen from reaching the platinum and disrupting its catalytic performance.

"The main challenge for most catalysts is the long-term stability of the materials" explained Garcia-Esparza. "So it is an important step to have an acid-tolerant material capable of preventing the water-forming back reaction that slows down water splitting."

"Nevertheless, we are still far from a commercial device and more work needs to be done," said Garcia-Esparza.

Media Contact

Michelle D'Antoni
michelle.dantoni@kaust.edu.sa

http://kaust.edu.sa/ 

Michelle D'Antoni | EurekAlert!

More articles from Power and Electrical Engineering:

nachricht Researchers take next step toward fusion energy
16.11.2017 | Texas A&M University

nachricht Desert solar to fuel centuries of air travel
16.11.2017 | SolarPACES

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>