Accenture: Australia LNG industry could become world’s largest
BMW making water pump wheel for DTM racecars and Z4 GT3s using 3D printing; ideal for small batch production

Toyota reports new real-time observation method sets stage for more efficient, durable fuel cell stacks

Toyota Motor Corporation and Japan Fine Ceramics Center (JFCC) have developed a new observation technique that allows researchers to monitor the behavior of nanometer-sized particles of platinum during chemical reactions in fuel cells, so that the processes leading to reduced catalytic reactivity can be observed in real-time.

The aim of the new technique is to identify the behavior, conditions and materials that make platinum catalyst nanoparticles critical to fuel cell efficiency and longevity prone to “coarsening”, with the accompanying degradation of capability. The new real-time observation technique could lead to a new generation of more efficient and durable fuel cell stacks, Toyota suggested. Toyota researchers will present the technique and their findings at the upcoming 2015 JSAE Annual Congress (Spring).

Top: Real-time observation of fuel cell catalyst degradation. Bottom: The dotted lines show the coarsening of platinum nanoparticles on top of a carbon carrier. The platinum particles have moved and joined together forming larger, coarser platinum nanoparticles. Click to enlarge.


Platinum is an essential catalyst for the electricity-producing chemical reactions occurring between oxygen and hydrogen in fuel cell stacks. Reduced reactivity is the result of “coarsening” of platinum nanoparticles—a process whereby the nanoparticles increase in size and decrease in surface area. Up until now, however, it has not been possible to observe the processes leading to coarsening, making it difficult to analyze the root causes.

The new observation method can enable discovery of the points on the carbon carrier where platinum coarsens, as well as level of voltage output during the coarsening process. The method can also help determine the different characteristics of various types of carrier materials. This all-aspect analysis can provide direction to R&D focused on improving the performance and durability of the platinum catalyst, and of the fuel cell stack.

The conventional method of platinum nanoparticle observation is a fixed-point comparison of pre-reaction platinum particles with post-reaction particles. Through this method, it was discovered that post-reaction platinum nanoparticles are coarser with reduced reactivity. But, the causes of this reduction can only be hypothesized due to the inability to observe the behavioral processes leading up to the coarsening.

Plane view (left) and cross-section (right) of microscopic electrochemical cells used as samples. The engineers use silicon nitride (SiN) film to confine electrolytes within a thickness of several 100 nm. Click to enlarge.

In contrast, the new observation technique uses micro-electromechanical systems technology to create millimeter-sized microscopic electrochemical cells that can simulate the exact environment and conditions occurring in fuel cells. This, in addition to a newly developed method of applying voltage—and voltage changes—to samples mounted inside a transmission electron microscope, allows the coarsening process to be observed in real-time at all stages as electricity is generated.

Schematic diagram showing the broad finding that platinum nanoparticles migrate over carbon and coarsen. Click to enlarge.

The technique can be used to analyze the relationship between voltage changes during driving—e.g., the voltage changes between start, idling, high load, acceleration and deceleration—and platinum nanoparticle behavior changes.

Background. Fuel cells generate electricity through the chemical reaction of onboard hydrogen gas with airborne oxygen. More specifically, each individual cell generates electricity through the chemical reaction between each oxygen cathode and hydrogen anode, with water produced as a byproduct.

During the chemical reaction, hydrogen molecules are separated into electrons and hydrogen ions at the hydrogen anode, where the platinum catalyst strips away the electrons from the hydrogen molecule. The electrons travel to the oxygen cathode, generating electricity to power the motor. Meanwhile, the hydrogen ions cross a polymer membrane to reach the oxygen cathode, where water is produced as a byproduct of hydrogen ions and electrons being exposed to airborne oxygen. Platinum also functions as the catalyst for this reaction.

Anodes and cathodes are primarily composed of platinum nanoparticles and carbon. Platinum nanoparticles are complex bodies of platinum atoms (hundreds of thousands to millions of atoms). Click to enlarge.

Platinum is essential for electricity generation in fuel cells, playing a vital role in increasing fuel cell electricity generation efficiency.

Catalytic role of platinum nanoparticles. Click to enlarge.

However, platinum is scarce and costly. Furthermore, as electricity is generated, platinum nanoparticles coarsen, thereby decreasing fuel cell output. In order to prevent coarsening and maintain catalytic performance, the behavior underlying the coarsening process must be identified. However, the minute scale of the platinum nanoparticles renders observation via conventional means difficult.



Further research will/could lead to lower cost, more efficient, longer lasting catalists for future FCs and electrolizers.

If so, FCs currently with 2X the efficiency of average ICEs could become 3X as efficient as ICEs, probably cheaper to mass produce and certainly cleaner to operate.

PHEVs with a small FC range extender may become an interesting option, especailly for cold weather areas.


The levelised cost of producing electricity from fuel cells seems to be much closer to being competitive than I had realised:

'Electricity produced from fuel cells costs about US$0.09 to US$0.12 a kilowatt-hour, depending on factors including gas prices, according to manufacturers. That compares with about US$0.09 for coal and US$0.06 for power plants that burn gas.'

I'd like to see how they arrived at those figures, but on the face of it it is hopeful as in addition to being clean running their almost NOx free emissions mean that it is possible to be much more nearly economic in financial and monetary terms for carbon capture as the stream is nearly pure and does not require energy intensive scrubbing.

And as the cherry on top:

'For each megawatt-hour of power the fuel cell system generates, CO2 emissions will be reduced by 18 to 25%. Over a project life of ten years, the system will reduce Honda’s carbon dioxide emissions by approximately 16 million pounds. Fuel cells convert fuels – in this case, natural gas – into electricity through an electrochemical process that is much more efficient than combustion, thereby reducing CO2 emissions of fossil fuels. Additionally, fuel cell technology delivers extraordinary water savings as it requires no water beyond an injection of 240 gallons at start-up. Compared to the average water demands of California power plants, it is estimated that Honda will save more than 3.25 million gallons of equivalent water used per year.'

This tiny water usage is invaluable in water-stressed areas ( California, I am looking at you! )


I forgot to mention that the modularity of fuel cells means that they are great for combined heat and power, so raising the thermal plus electrical efficiency to 85-90%.


I found some levelised costs, and Doosan seem to be in the right area, although understandably coming in at the low end of the range for cost:

Note that these costs do not include any allowance for intermittency, back up and reliability.

Fuel cells score heavily in all these areas, being despatchable and having very good reliability, much better than diesel generators.

Here is a study not based on current costs, but all technologies projected to 2020:

Note the lower costs for micro FC systems compared to residential PV, and for medium FC as against commercial and industrial PV.

And that is before intermittency and its consequences are considered.


Tks DM for the added info on FCs economics.

We have huge (20,000 mega-watts) surpluses of clean Hydro/Wind energy about 16 hours/day. Most of the unused excess surpluses could be used, at very low cost, to produce clean H2.

The clean H2 produced could be enough for 2 FCEVs per family and to produce XXX mega-watt of clean electricity for peak demand hours.

It could a win-win solution.

Some of the CAN $3.5B/year profit from our Hydro energy generation/distribution network could be used to install and operate the H2/FC network on an as required basis. Gasoline and diesel fuels ICEVs could be progressively replaced with BEVs and FCEVs over 20 years or so.

The comments to this entry are closed.