22 Mar 2016
Groundbreaking research at Griffith University is leading the way in clean energy, with the use of carbon as a way to deliver energy using hydrogen.
Professor Xiangdong Yao and his team from Griffith’s Queensland Micro- and Nanotechnology Centre have successfully managed to use the element to produce hydrogen from water as a replacement for the much more costly platinum.
“Hydrogen production through an electrochemical process is at the heart of key renewable energy technologies including water splitting and hydrogen fuel cells,” says Professor Yao.
“Despite tremendous efforts, exploring cheap, efficient and durable electrocatalysts for hydrogen evolution still remains a great challenge.
“Platinum is the most active and stable electrocatalyst for this purpose, however its low abundance and consequent high cost severely limits its large-scale commercial applications.
“We have now developed this carbon-based catalyst, which only contains a very small amount of nickel and can completely replace the platinum for efficient and cost-effective hydrogen production from water.
“In our research, we synthesize a nickel-carbon-based catalyst, from carbonization of metal-organic frameworks, to replace currently best-known platinum-based materials for electrocatalytic hydrogen evolution.
“This nickel-carbon-based catalyst can be activated to obtain isolated nickel atoms on the graphitic carbon support when applying electrochemical potential, exhibiting highly efficient hydrogen evolution performance and impressive durability.”
Proponents of a hydrogen economy advocate hydrogen as a potential fuel for motive power including cars and boats and on-board auxiliary power, stationary power generation (e.g., for the energy needs of buildings), and as an energy storage medium (e.g., for interconversion from excess electric power generated off-peak).
Professor Yao says that this work may enable new opportunities for designing and tuning properties of electrocatalysts at atomic scale for large-scale water electrolysis.
- Lili Fan, Peng Fei Liu, Xuecheng Yan, Lin Gu, Zhen Zhong Yang, Hua Gui Yang, Shilun Qiu, Xiangdong Yao.Atomically isolated nickel species anchored on graphitized carbon for efficient hydrogen evolution electrocatalysis. Nature Communications, 2016; 7: 10667 DOI: 10.1038/ncomms10667
GoPro-Funded Startup’s Tech Turns Seawater into Hydrogen
Joi Scientific held a forum on Tuesday at its Kennedy Space Center-based headquarters in Florida to discuss its technology that can convert saltwater into a hydrogen power source.
Founder and CEO Traver Kennedy didn’t elaborate on the specific procedure his technology uses to create hydrogen,writes Fortune. He told the audience the process would be similar to something that “happens in nature,” but could potentially produce “hydrogen on demand” whenever a customer wants it.
A successful launch of Joi’s technology could create a new paradigm for energy innovation. Scientists have concluded that the extraction process of transforming hydrogen into water can be expensive and take up a considerable amount of energy, but Joi said his technology’s process would be different,reports the Orlando Sentinel.
The company recently raised a $5M investment from the Woodman Family Trust, a fund led by Dean Woodman. He’s the father of Nick Woodman, founder and CEO of popular camera provider GoPro.
Joi will use the money to kick-start the commercialization process, reports Fortune. Kennedy told the publication he started discussions with manufacturers a year ago about licensing agreements to help these partners “incorporate it into their gear to make hydrogen to power fuel cells, burners, and boilers.”
Kennedy plans on installing his technology into a few projects later this year.
22 Jan 2016
Scientists at Indiana University have created a highly efficient biomaterial that catalyzes the formation of hydrogen—one half of the “holy grail” of splitting H2O to make hydrogen and oxygen for fueling cheap and efficient cars that run on water.
A modified enzyme that gains strength from being protected within the protein shell—or “capsid”—of a bacterial virus, this new material is 150 times more efficient than the unaltered form of the enzyme.
The process of creating the material was recently reported in “Self-assembling biomolecular catalysts for hydrogen production” in the journal Nature Chemistry.
“Essentially, we’ve taken a virus’s ability to self-assemble myriad genetic building blocks and incorporated a very fragile and sensitive enzyme with the remarkable property of taking in protons and spitting out hydrogen gas,” said Trevor Douglas, the Earl Blough Professor of Chemistry in the IU Bloomington College of Arts and Sciences’ Department of Chemistry, who led the study. “The end result is a virus-like particle that behaves the same as a highly sophisticated material that catalyzes the production of hydrogen.”
Other IU scientists who contributed to the research were Megan C. Thielges, an assistant professor of chemistry; Ethan J. Edwards, a Ph.D. student; and Paul C. Jordan, a postdoctoral researcher at Alios BioPharma, who was an IU Ph.D. student at the time of the study.
The genetic material used to create the enzyme, hydrogenase, is produced by two genes from the common bacteria Escherichia coli, inserted inside the protective capsid using methods previously developed by these IU scientists. The genes, hyaA and hyaB, are two genes in E. coli that encode key subunits of the hydrogenase enzyme. The capsid comes from the bacterial virus known as bacteriophage P22.
The resulting biomaterial, called “P22-Hyd,” is not only more efficient than the unaltered enzyme but also is produced through a simple fermentation process at room temperature.
The material is potentially far less expensive and more environmentally friendly to produce than other materials currently used to create fuel cells. The costly and rare metal platinum, for example, is commonly used to catalyze hydrogen as fuel in products such as high-end concept cars.
“This material is comparable to platinum, except it’s truly renewable,” Douglas said. “You don’t need to mine it; you can create it at room temperature on a massive scale using fermentation technology; it’s biodegradable. It’s a very green process to make a very high-end sustainable material.”
In addition, P22-Hyd both breaks the chemical bonds of water to create hydrogen and also works in reverse to recombine hydrogen and oxygen to generate power. “The reaction runs both ways—it can be used either as a hydrogen production catalyst or as a fuel cell catalyst,” Douglas said.
The form of hydrogenase is one of three occurring in nature: di-iron (FeFe)-, iron-only (Fe-only)- and nickel-iron (NiFe)-hydrogenase. The third form was selected for the new material due to its ability to easily integrate into biomaterials and tolerate exposure to oxygen.
NiFe-hydrogenase also gains significantly greater resistance upon encapsulation to breakdown from chemicals in the environment, and it retains the ability to catalyze at room temperature. Unaltered NiFe-hydrogenase, by contrast, is highly susceptible to destruction from chemicals in the environment and breaks down at temperatures above room temperature—both of which make the unprotected enzyme a poor choice for use in manufacturing and commercial products such as cars.
These sensitivities are “some of the key reasons enzymes haven’t previously lived up to their promise in technology,” Douglas said. Another is their difficulty to produce.
“No one’s ever had a way to create a large enough amount of this hydrogenase despite its incredible potential for biofuel production. But now we’ve got a method to stabilize and produce high quantities of the material—and enormous increases in efficiency,” he said.
The development is highly significant according to Seung-Wuk Lee, professor of bioengineering at the University of California-Berkeley, who was not a part of the study.
“Douglas’ group has been leading protein- or virus-based nanomaterial development for the last two decades. This is a new pioneering work to produce green and clean fuels to tackle the real-world energy problem that we face today and make an immediate impact in our life in the near future,” said Lee, whose work has been cited in a U.S. Congressional report on the use of viruses in manufacturing.
Beyond the new study, Douglas and his colleagues continue to craft P22-Hyd into an ideal ingredient for hydrogen power by investigating ways to activate a catalytic reaction with sunlight, as opposed to introducing elections using laboratory methods.
“Incorporating this material into a solar-powered system is the next step,” Douglas said.
More information: Paul C. Jordan et al. Self-assembling biomolecular catalysts for hydrogen production, Nature Chemistry (2015). DOI: 10.1038/nchem.2416
Mimicking photosynthesis is not easy. The bottleneck of artificial photosynthesis is visible light, because converting it into other forms of energy is not efficient. Researchers at Michigan Technological Univ. have found a way to solve this issue, leading to an efficient technique to produce hydrogen fuel. Their work was published in the Journal of Physical Chemistry.
The technique was developed by Yun Hang Hu, the Charles and Carroll McArthur professor of Materials Science and Engineer, and his PhD student, Bing Han, at Michigan Tech.
“Hydrogen is the future of cars,” says Hu. “And if you want to power hydrogen cars, you have to make hydrogen fuels.”
In this new hydrogen production process, the key is the interactions of a catalyst, light and a sacrificial molecule.
Playbook of black titanium dioxide, methanol and light
As if in a complex sports game, the exchanges and counters between the materials used to split water look like a chemistry playbook. The players are black titanium dioxide (TiO2) and methanol (CH3OH) pitted against electron-hole recombination.
The goal of the game is to produce hydrogen molecules. Basically, that’s done by moving an electron from one place to another, like kicking a football to get a field goal. To make that score, a water molecule captures an electron excited within a material. When excited, electrons move up and down in different bands; the lower one here is the valence band and the higher one is the conduction band. The valence band and the conduction band are like goal posts, and between them is the band gap, which is like the playing field. The excited electron is the ball being passed around.
Solar energy, with both ultraviolet (UV) and visible light energy, is what gets this ball rolling. Light energy bounces off the first player, titanium dioxide, which is the material where the valence band and conduction band are in play. That excites an electron, making it a photo-excited charge that shoots up towards the conduction band. For UV light, the playing field is pretty big, and the band gap stretches 3.2 electron volts wide.
Here’s where the game gets more complicated, Harry Potter Quidditch-style, with balls that move quickly on their own. Electrons tend to zip like a golden snitch, and they sometimes misbehave, scurrying back to their starting place in the valence band, which negates the goal score and H2 production.
Enter player two: methanol. When the photo-excited electron shoots toward the conduction band, the methanol donates an electron via an oxidation reaction to swoop in and block the open spot left in the valence band. This sacrificial agent acts as a defense against the photo-excited electron snitching and scurrying its way back.
Playing in the visible light spectrum
The play between titanium dioxide, methanol and UV light serves up hydrogen (H2) molecules, However, UV is only a very small part (4%) of solar energy. It is important to use visible light, since it constitutes about 45% of solar energy. Hu’s team has been able to increase the yield and energy efficiency up to two magnitudes greater than previously reported results using visible light instead of UV. But they had to change the playing field to do so.
“It’s a two-part process,” Hu says, explaining that the catalyst is black titanium dioxide (with 1 percent platinum), which attaches to a silicon dioxide substrate in their set-up. Hu’s team first generated a “light-diffuse-reflected surface” for the silicon dioxide, making it bumpy, which traps light waves and bounces them around. “We put the catalyst on the scattered surface, and it can increase the light absorption by one hundred times,” he explains.
Light absorption is an important step that generates photo-excited electrons, but it’s only part of what’s needed. Using visible light shortens the playing field, altering the band gap to only 1.3 electron volts in black titanium oxide. Specifically, that’s because an electron is excited to conduction band from Ti3+ energy level instead of the valence band, which is like starting at the 10-yard line instead of the 50-yard line.
The photo-excited electron has less distance to travel to the conduction band, but methanol doesn’t like to play along. The shortened distance from methanol to Ti3+ energy level greatly reduces methanol’s oxidation reaction, giving it less motivation to fill the leftover hole in the Ti3+ energy level. So, it needed a little heat in the second step of the process to get that reaction going again.
“We used temperature to increase the energy for methanol oxidation to donate electrons,” Hu says, adding that in the experiment they found 280 degrees Celsius to be the sweet spot.
With the modified silicon dioxide substrate and heat, Hu’s team also had to design a different set-up for the experiment. The water they used was steam, pushed into a chamber where it collided with a disk of roughened silicon dioxide studded with black titanium dioxide-platinum catalyst. Visible light then excited the electrons, and the hydrogen could then be syphoned off.
“The set-up is not complicated,” Hu says. “It’s actually convenient for scaling up commercially.”
Furthermore, this work created a hybrid process using both light and heat, which has opened a new door for visible light photosynthesis. The method is a big step closer to mimicking photosynthesis.
Source: Michigan Technological Univ.