Concordia Journal Home > Archives > November 8, 2007 issue >

Potential of particles 

By Dawn Wiseman

In engineering, innovation requires combining pure science with real world application. Rolf Wüthrich (Mechanical and Industrial Engineering) is looking to do just that. His research into the effective production of nanoparticles may one day have us driving more energy- efficient, cleaner-fuel-burning cars. It has already won him a 2007-2008 Petro-Canada Young Innovator Award.

Nanoresearchers work in the world of the incredibly tiny. The particles and structures they study are measured in billionths of meters. As Wüthrich pointed out, “On this level the physical properties of materials — things like melting point and chemical properties — can change drastically.”

These changes in what were once thought to be constants provide a number of challenges for researchers. For one thing, nanoparticles are quite difficult to consistently produce.

“It’s a bit like gourmet cooking,” said Wüthrich. “ If you don’t get everything just right, you’re not sure what the end result will be.” Particles can vary widely in size or chemical structure, not the kind of adequate control needed for high-level experimentation.

While still at the Swiss Federal Institute of Technology in Lausanne, however, Wüthrich invented a much simpler method for producing metal alloy nanoparticles. “We are using a physical as opposed to a chemical process,” he explained; not so much cooking, as constructing.

The new method can be used to consistently produce nanoparticles of a desired size. He is collaborating with Christina Bock at the National Research Council in Ottawa to determine their chemical structure. “We are very grateful for this collaboration because it give us access to crucial equipment and expertise.”

For the Petro-Canada research, Wüthrich is testing his method for potential use in fuel cells.

Like batteries, fuel cells convert chemical energy into electrical energy. Unlike batteries, which eventually die, fuel cells can be replenished indefinitely.

In recent years, the media has provided a good amount of coverage to hydrogen fuel cells, because the only by-product of the energy they produce is water.

Unfortunately, hydrogen has a few drawbacks as a fuel, at least for motor vehicles. Its production actually requires the burning of carbon-based fuel (so there is ultimately no net gain in carbon emissions), and, as Wüthrich added, “It has some safety issues.” In fact it explodes (violently), and (in sufficient quantity) with enough energy to lift the space shuttle into orbit.

Until production and safety issues of hydrogen can be addressed, Wüthrich and others are looking at alternative fuel cell technologies which use carbon-based fuels such as methanol.

His research begins by creating platinum-ruthenium alloy cores using the recently invented nanoparticle technology.

“By covering the surface of the core with millions of these nanoparticles, we significantly increase its surface area and, we hope, the efficiency of the process in the fuel cell.” More surface area means more contact between the methanol and the nanoparticles, and theoretically more energy production. Ruthenium is key to the process.

“The chemical reaction which occurs between platinum and methanol is well known,” Wüthrich explained. “It’s very good at producing energy, too good in fact.” One of the by-products of the reaction is pure carbon, which ends up quickly coating the platinum core and stopping the reaction all together.

By adding ruthenium to the platinum, the resulting alloy becomes a catalyst for a secondary reaction that keeps the carbon from settling on the core. “The drawback is that the fuel cell ends up giving off carbon emissions.”

However, Wüthrich underlined, “Methanol is much cleaner-burning than our current gasoline. And in the longer term, we hope to use the process with ethanol, which burns even cleaner again. We are pretty sure it will work.”

Wüthrich is using the $10,000 Petro-Canada award to hire a PhD student and to purchase the metals required for core production, “These materials are not cheap,” he said with a smile.