Researchers at Rice University have discovered that graphene quantum dots (GQDs) serve as better catalysts in fuel cells than does platinum. And the quantum nanodots are made from (cover your eyes fossil fuel rejectionists) coal.

According to Rice, “The Rice lab of chemist James Tour created dots known as GQDs from coal last year and have now combined these nanoscale dots with microscopic sheets of graphene, the one-atom-thick form of carbon, to create a hybrid that could greatly cut the cost of generating energy with fuel cells …

“… The lab discovered boiling down a solution of GQDs and graphene oxide sheets (exfoliated from common graphite) combined them into self-assembling nanoscale platelets that could then be treated with nitrogen and boron. The hybrid material combined the advantages of each component: an abundance of edges where chemical reactions take place and excellent conductivity between GQDs provided by the graphene base. The boron and nitrogen collectively add more catalytically active sites to the material than either element would add alone.”

Platinum-free fuel cells are something scientists have been feverishly working on in the last 5 years. Cheaper fuel cells will mean less expensive fuel cell vehicles which in turn will mean higher buyer acceptance.

Filed under: Fuel Cells

“It’s almost impossible to do a good fuel cell without platinum as a catalyst,” Vlatko Vlatkovic, chief engineering officer of GE’s Power Conversion division, said in an interview in London. “Very little goes in, but if you scale it up, there’s not enough platinum in the world.”

GE’s comments reveal constraints that may keep fuel cells from penetrating the energy market as a mainstream technology. Fuel cells use hydrogen or natural gas to generate power through a chemical reaction, and the most common technology needs the scarce element as a catalyst.

Shares of U.S. fuel cell companies such as Plug Power Inc. and FuelCell Energy Inc. have surged in the past two months as rising sales convince investors the technology may become a viable alternative to burning fossil fuels to produce electricity.

The most common fuel-cell design uses proton-exchange technology, which requires platinum or palladium, some of the earth’s rarest elements. Platinum currently sells for about $1,400 an ounce. Palladium goes for about $760, data compiled by Bloomberg show.

That means Plug Power and its competitors have a “viable niche,” but one that would be very hard to scale-up massively, Vlatkovic said.

Scale is important to GE, and fuel cells don’t offer the potential to become an important product for a company that had revenue of $146 billion last year.

Plug Power

Plug had sales of $26.6 million in 2014. Chief Executive Officer Andy Marsh does not see the use of platinum as a deterrent to growth. The Latham, New York-based company makes fuel-cell systems for forklifts used in warehouses and factories.

Platinum’s high cost has encouraged manufacturers to find ways to use less of the metal, and the cost of the material is now a small fraction of the total price of fuel cell systems, Marsh said in an interview.

“We can reclaim about 90 percent of that after its useful life,” Marsh said March 25. “I don’t see it as a deterrent to growth.”

GE Power Conversion spent time investigating fuel cell technology and concluded it’s “very challenging,” its head engineer said. The unit is researching an alternative — solid oxide fuel cells — that don’t need noble metals. An actual product is “very far off,” he said.

Bloom Energy Corp., based in Sunnyvale,California, already sells solid oxide fuel cells. That company also has a “small” niche application, according to Vlatkovic.

GE Power Conversion develops technology for renewable energy as well as oil and gas infrastructure.

Copyright 2014 Bloomberg

Lead image: Platinum bars via Shutterstock

The Rice lab of chemist James Tour created dots known as GQDs from coal last year and have now combined these nanoscale dots with microscopic sheets of graphene, the one-atom-thick form of carbon, to create a hybrid that could greatly cut the cost of generating energy with fuel cells.

The research is the subject of a new paper in the American Chemical Society journal ACS Nano.

The lab discovered boiling down a solution of GQDs and graphene oxide sheets (exfoliated from common graphite) combined them into self-assembling nanoscale platelets that could then be treated with nitrogen and boron. The hybrid material combined the advantages of each component: an abundance of edges where chemical reactions take place and excellent conductivity between GQDs provided by the graphene base. The boron and nitrogen collectively add more catalytically active sites to the material than either element would add alone.

«The GQDs add to the system an enormous amount of edge, which permits the chemistry of oxygen reduction, one of the two needed reactions for operation in a fuel cell,» Tour said. «The graphene provides the conductive matrix required. So it’s a superb hybridization.»

The Tour lab’s material outperformed commercial platinum/carbon hybrids commonly found in fuel cells. The material showed an oxygen reduction reaction of about 15 millivolts more in positive onset potential — the start of the reaction — and 70 percent larger current density than platinum-based catalysts.

The materials required to make the flake-like hybrids are much cheaper, too, Tour said. «The efficiency is better than platinum in terms of oxygen reduction, permitting one to sidestep the most prohibitive hurdle in fuel-cell generation — the cost of the precious metal,» he said.

Rice graduate student Huilong Fei is the paper’s lead author. Co-authors are graduate students Ruquan Ye, Gonglan Ye, Yongji Gong, Zhiwei Peng and Errol Samuel; research technician Xiujun Fan; and Pulickel Ajayan, the Benjamin M. and Mary Greenwood Anderson Professor in Mechanical Engineering and Materials Science and of chemistry and chair of the Department of Materials Science and NanoEngineering, all of Rice.

Tour is the T.T. and W.F. Chao Chair in Chemistry as well as a professor of materials science and nanoengineering and of computer science.

Michigan Technological University researcher Reza Shahbazian-Yassar has made it his business to better map the ion’s long, strange trip — and perhaps make it smoother and easier. His ultimate aim: to make better batteries, with more power and a longer life.

Using transmission electron microscopy, Anmin Nie, a senior postdoctoral researcher in Shahbazian-Yassar’s research group, has recently documented what can happen to anodes as lithium ions work their way into them, and it’s not especially good. The research was recently published in the journal Nano Letters.

«We call it atomic shuffling,» says Shahbazian-Yassar, the Richard and Elizabeth Henes Associate Professor in Nanotechnology. «The layered structure of the electrode changes as the lithium goes inside, creating a sandwich structure: there is lots of localized expansion and contraction in the electrode crystals, which helps the lithium blaze a trail through the electrode.»

The atomic shuffling not only helps explain how lithium ions move through the anode, in this case a promising new material called zinc antimonide. It also provides a clue as to why most anodes made of layered materials eventually fail. «We showed that the ions cause a lot of local stress and phase transitions,» Anmin said.

The paper, «Lithiation-Induced Shuffling of Atomic Stacks,» is coauthored by Shahbazian-Yassar, Nie and graduate student Hasti Asayesh-Ardakani of Michigan Tech’s Department of Mechanical Engineering-Engineering Mechanics; Yingchun Cheng, Yun Han and Udo Schwingenschlogl of King Abdulla University of Science and Technology, in Saudi Arabia; Runzhe Tao, Farzad Mashayet and Robert Klie of the University if Illinois at Chicago; and Sreeram Vaddiraju of Texas AM University.

The microscopy was conducted at the University of Illinois at Chicago.

«Toxicity is probably the single most important problem in cost-effective biofuels production,» says Gregory Stephanopoulos, the Willard Henry Dow Professor of Chemical Engineering at MIT.

Now Stephanopoulos and colleagues at MIT and the Whitehead Institute for Biomedical Research have identified a new way to boost yeast tolerance to ethanol by simply altering the composition of the medium in which the yeast are grown. They report the findings, which they believe could have a significant impact on industrial biofuel production, in today’s issue of the journal Science.

Ethanol and other alcohols can disrupt yeast cell membranes, eventually killing the cells. The MIT team found that adding potassium and hydroxide ions to the medium in which yeast grow can help cells compensate for that membrane damage. By making these changes, the researchers were able to boost yeast’s ethanol production by about 80 percent. They also showed that this approach works with commercial yeast strains and other types of alcohols, including propanol and butanol, which are even more toxic to yeast.

«The more we understand about why a molecule is toxic, and methods that will make these organisms more tolerant, the more people will get ideas about how to attack other, more severe problems of toxicity,» says Stephanopoulos, one of the senior authors of the Science paper.

«This work goes a long way to squeezing the last drop of ethanol from sugar,» adds Gerald Fink, an MIT professor of biology, member of the Whitehead Institute, and the paper’s other senior author. Postdoc Felix Lam is the paper’s lead author, and graduate student Adel Ghaderi also contributed to the study.

Reinforcing cell defenses

The research team began this project searching for a gene or group of genes that could be manipulated to make yeast more tolerant to ethanol, but this approach did not yield much success. However, when the researchers began to experiment with altering the medium in which yeast grow, they found some dramatic results.

By augmenting the yeast’s environment with potassium chloride, and increasing the pH with potassium hydroxide, the researchers were able to dramatically boost ethanol production. They also found that these changes did not affect the biochemical pathway used by the yeast to produce ethanol: Yeast continued to produce ethanol at the same per-cell rate as long as they remained viable. Instead, the changes influenced their electrochemical membrane gradients — differences in ion concentrations inside and outside the membrane, which produce energy that the cell can harness to control the flow of various molecules into and out of the cell.

Ethanol increases the porosity of the cell membrane, making it very difficult for cells to maintain their electrochemical gradients. Increasing the potassium concentration and pH outside the cells helps them to strengthen the gradients and survive longer; the longer they survive, the more ethanol they make.

«By reinforcing these gradients, we’re energizing yeast to allow them to withstand harsher conditions and continue production. What’s also exciting to us is that this could apply beyond ethanol to more advanced biofuel alcohols that upset cell membranes in the same way,» Lam says.

The researchers found that they could also prolong survival, but not as much, by engineering the yeast cells to express more potassium and proton pumps, which are located in the cell membrane and pump potassium in and protons out.

Industrial relevance

Before yeast begin their work producing ethanol, the starting material, usually corn, must be broken down into glucose. A significant feature of the new MIT study is that the researchers did their experiments at very high concentrations of glucose. While many studies have examined ways to boost ethanol tolerance at low glucose levels, the MIT team used concentrations of about 300 grams per liter, similar to what would be found in an industrial biofuel fermenter.

«If you really want to be relevant, you’ve got to go to these levels. Otherwise, what you learn at low ethanol levels is not likely to translate to industrial production,» Stephanopoulos says.

In more recent experiments, the MIT researchers have used this method to bump ethanol productivity even higher than reported in the Science paper. They are also working on using this approach to boost the ethanol yield from various industrial feedstocks that, because of starting compounds inherently toxic to yeast, now have low yields.

Consisting of a grouping of Solar Decathlon houses that students at MST built for competitions between 2002 and 2009, the solar village is a project created in collaboration with Missouri ST students, faculty and staff, along with members of the university’s microgrid advisory board (Investor-owned utility Ameren, City Utilities of Springfield, Rolla Municipal Utilities and Electric Power Research Institute), several Missouri manufacturers (Milbank and Ford Motor Company) and the Army Corps of Engineers. The engineer-of-record and installer for the project was Microgrid Solar, a U.S. and Caribbean solar developer, installer, and engineering company based in St. Louis, MO.

The project has been in the works for two years and is expected to be complete by the end of next month.  A utility grant and the DOE Sunshot Initiative contributed funding for the project.

Project Specs

There are four former Solar Decathlon houses in the microgrid. The buildings each have 5- to 10-kW PV systems and there is a mix of crystalline silicon PV and thin film.  The buildings also have solar thermal systems for hot water.  The energy storage components consist of two 100 kW / 100 kWh lithium-ion iron nano-phosphate battery racks that were donated by A123 Systems. There is also a fuel cell and a heat recovery unit as part of the microgrid.

Graduate students currently live and work in the houses, which also include electric vehicle charging stations. The microgrid is built so that it can island from the utility grid indefinitely.

Even though the military has been designing microgrids for ten years now, the project is a first “from the perspective of testing new designs and new equipment in a very closely monitored research setting,” according to Marc Lopata, PE, the Principal Engineer on this project and President of Microgrid Solar.  “We have the capability to power any of the houses independently from the grid or the central plant,” he said. “And we have the capability to plug in new equipment for testing and do graduate level experimentation.”

Tony Arnold, Assistant Director of the Office of Sustainable Energy and Environmental Engagement at MST said in a statement that the solar village will be used “as a research tool and testing center for microgrid technology, battery technology and system communications.”  He believes that projects like the solar village need to be “scalable, replicable and flexible, so that we have the opportunity to test as many different scenarios as possible.”  According to Arnold, major utilities, companies and the U.S. Army’s Prime Power School have expressed interest in the project.

Advancing the New Energy Paradigm

Microgrids are of growing importance across the globe.  Last month, Renewable Energy World visited the Nice Grid in Carros, France. The Nice Grid uses solar PV, demand response and three different levels of energy storage in order to achieve a smarter grid that is able to “island” for up to four hours. 

The Missouri project, although much smaller in scale, will be used to test new equipment, software and firmware, as well as procedures for controlling the loads and supplies and procedures for how they communicate with utilities, according to Lopata. “Plus, I’m sure, a plethora of as-yet-to-be-imagined research topics,” he said adding that Microgrid Solar installed extra conduits in all the houses for potential future use.

Microgrid Solar installs microgrids in remote places such as the Caribbean and Lopata emphatically stated that microgrids “are not for everyone.”  Today, the cost of installing a microgrid that includes energy storage (a must in order to firm the power supply and dispatchability) is at least twice that of a normal utility grid connection and could be as high as five times that cost.  Lopata said microgrids only make sense in places where there is no existing grid, no utility, no local distribution or the power is unreliable or too expensive.  But all of that said, in locations where those conditions do apply, installing a microgrid could cut the levelized cost of energy (LCOE) significantly and improve the power supply, according to Lopata.

by Guest Blogger Stan Thompson

For three days this December, the 8th, 9th and 10th, the University of Birmingham UK will host the 50th anniversary celebration of the birth of High Speed Rail. The blessed event occurred in Japan in 1964 with the opening of Tokyo’s Shinkansen line.

Many of the top experts in this most fascinating (and literally “dashing”) element of world railway resurgence will be on hand in Birmingham to present—from Japan and elsewhere.

 www.birmingham.ac.uk/high-speed-rail

The motto  of the University of Birmingham is “Circles of Influence”.  In December, one big Circle will enfold Japan’s game-changing innovation.

High Speed Rail is a sort of shining city on the hill of railway resurgence. Hydrail (until Northern Germany’s announcement last week of 40 Alstom hydrail passenger consists by 2020) has been an obscure pilgrim struggling toward the distant summit.

But in Germany this year, Ing. Herbert Warcura of Austria gave the pilgrim a quick lift to the top with his presentation at the Neumünster, Schleswig-Holstein, Germany, Ninth International Hydrail Conference.

 (http://hydrail.org/sites/hydrail.org/files/9_Wancura.pdf)

A flare for the dramatic may be excused if I observe that Wancura’s 9IHC presentation—linking hydrail to High Speed Rail at last—recalls Michelangelo’s reaching hands on the Sistine Chapel!  Wancura’s speech described the first clear and feasible contact between these two paradigm-shifting railway technologies.

As one whose work has been greatly influenced by UB’s vision and action in the world of hydrail, I can speak with enthusiasm to the appropriateness of the “Circles of Influence” motto.

In 2010 in Istanbul, Turkey, North Carolina’s Sixth International Hydrail Conference had the honor of introducing Dr. Andreas Hoffrichter, who received Birmingham’s first hydrail Ph.D.  The following year, (now Dr.) Hoffrichter organized the Seventh International Hydrail Conference at the Birmingham Campus. As of 7IHC, UB’s “Circles of Influence” have been augmented by the international circles that the International Hydrail Conferences have been creating since 2005.

A year ago I spent a week in Shanghai advocating hydrail as a guest of Southwest Jiaotong University, China’s oldest and most prominent railway engineering school. That happened courtesy of an introduction by UK’s Centre for Railway Research and Education. In Shanghai, I had the honor of introducing Birmingham’s Professor Kevin Kendall, a Fellow of the Royal Society and a featured presenter U. Birmingham’s Hydrail Conference.

This week I had the pleasure of attending a hydrail masters thesis dissertation defense at the University of North Carolina at Charlotte—one of many that should flow from the emerging UNCC/UB affiliation springing from Birmingham’s outreach to North Carolina.

When the University at Charlotte, as part of its Birmingham affiliation, inaugurated a series of advanced railway technology lectures, the first speaker invited was Ing. Herbert Wancura.

It’s not surprising that the celebration of the Shinkansen High Speed Rail Line should have been organized by the Birmingham Centre for Railway Research and Education. Neither is it surprising that UNC-Charlotte also hosted a Shinkansen lecture in April, 2014, as part of the growing hydrail cooperation among universities.

Thanks go to Dr. Andreas Hoffrichter for sharing the news of the Shinkansen anniversary event!

To keep up with hydrail emergence around the world, visit Appalachian State University’s web site, http://www.hydrail.org .

Filed under: Conferences, Hydrail, Hydrogen Education

Researchers in the renewable energy sector are working hard in this respect. In this context, researchers in the UPV/EHU’s Department of Applied Chemistry are exploring possible solutions to improve the efficiency of mobile devices like, for example, mobile phones, laptop computers and vehicles. In other words, they are designing new ways of obtaining energy in a cleaner, safer and more affordable way.

Fuel cells are totally appropriate systems for substituting the batteries of mobile phones, laptop computers and vehicles. They turn the energy resulting from the combining of hydrogen and oxygen into electrical power, with water vapour being the only waste product. In other words, they generate energy in the same way that batteries do, but they do not contaminate.

However, if these fuel cells are to produce energy, they need an external supply of hydrogen, and right now storing hydrogen safely poses difficulties. That is why what could be a good option is to use a piece of infrastructure that produces gaseous hydrogen inside the cell itself. In these cases methanol is normally used as the raw material. And methanol is in fact one of the most important fuels used to produce hydrogen. For example, instead of powering mobile phones, laptop computers and vehicles with hydrogen, methanol can be added to them so that the methanol is turned into hydrogen depending on the needs of the device. In the end, the process is the same even though it takes place in two phases.

A special piece of infrastructure has been designed in the course of this research work: a reactor comprising micro-channels. And a micro-reactor a hundred times smaller than a conventional reactor system has been developed. And the size of the reactor is in fact crucial in the case of all these mobile devices. «It is no easy task developing a reactor comprising micro-channels,» explained Oihane Sanz, a researcher at the UPV/EHU’s Department of Applied Chemistry. «The choice of materials, the machining of the micro-channels, the assembly of the system and the catalytic coating, among other things, have to be carried out with the utmost care.»

They have seen that these reactors comprising micro-channels contribute towards improving the heat transfer to convert the methanol into hydrogen. Thanks to this, the reaction temperature is properly controlled and, therefore, the hot spots in which the carbon monoxide (CO) arises are minimized. If CO is produced together with the hydrogen, the fuel cell can in fact become contaminated. As a result of this contamination, the cell will not function properly and, therefore, the production of energy is halted.

A stable catalyst

Likewise, choosing a catalyst and using a suitable method of depositing it are indispensable conditions for the reaction to take place as efficiently as possible. «One of the biggest difficulties of these reactors made up of micro-channels is inserting the catalyst into these channels that are so small. That is why the aim of this research has been to design a stable catalyst and insert it into the system in the best way possible. In the processes to obtain hydrogen from methanol, palladium (Pd) catalysts are used, and this is precisely what the researchers have done in this case. Specifically, they used PdZnO. Often, «when incorporating the catalysts into reactors made up of micro-channels, the characteristics of the catalysts are lost. However, with the catalysts used in this study, we have managed not only to maintain their characteristics but also carry out the process easily.»

With the right infrastructure and catalyst, the micro-reactor designed by the UPV/EHU researchers produces 30 LH₂/h.g; the conversion of methanol is 95%, and that of carbon monoxide (CO) less than 1%. «It is very important to control the production of carbon monoxide as it could contaminate the fuel cell,» stressed Sanz. «Systems that produce a bigger quantity of hydrogen (12-50 LH₂/h.g) have been documented, but the conversion of the methanol is lower (80 %, and, in some cases, 4 %), and, what is more, marginal products are generated,» added Sanz. In the end, this design «enables us to develop a cleaner, safer and less costly process,» concluded Sanz.