Fuel for thought
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Photo by
Wendy Monk Dr. Peter Pickup |
Imagine never having to
replace or recharge the batteries in your remote control. Although total
elimination of batteries is unlikely at this point, researchers are now
looking at alternatives that could cut into the battery market. Dr. Peter
Pickup, Chemistry, is researching one probable replacement: fuel cells.
Dr. Pickup’s recent research has focused on materials to be used
in the electrolyte membrane and electrodes of the cell. Although there
are many different fuel cells, his research has concentrated on the Proton
Exchange Membrane (PEM) fuel cell.
A fuel cell is an electrochemical cell consisting primarily of a polymeric
membrane and an electrode on either side. A fuel cell converts chemical
energy from a fuel and combines it with oxygen to produce electrical energy;
“It’s like a battery except it
doesn’t discharge because fuel is supplied to it,” Dr. Pickup
explained.
The fuel predominately used is hydrogen. “Hydrogen gas reacts at
one electrode and produces a current of electrons and protons which give
electrical power when the protons combine with oxygen at the other electrode.
In addition to the electrical energy produced, the fuel cell produces
water.” According to Dr. Pickup, “the effect of the water depends
on the application — the rate of production of water is so small
that it could evaporate and not cause a problem, but it could potentially
be a problem.
“As a fuel, hydrogen is not very convenient; it is not particularly
dangerous but it is very difficult to store,” Dr. Pickup continued.
That is why part of his research is focused on finding alternative fuels.
“Methanol is viewed as one of the most promising fuels because it
is readily available and can be easily stored,” Dr. Pickup said.
Methanol is used in direct methanol fuel cells which are essentially structurally
the same as hydrogen cells. However, methanol fuel cells can produce electrical
energy using two techniques. The methanol can be reformed to hydrogen
through a chemical reaction with water, and then the cell operates as
a hydrogen cell, or the methanol can be used directly in the fuel cell.
“One of the less attractive features of the direct methanol cell
is the production of carbon dioxide as a by-product — however, this
will usually also occur in a hydrogen production. So, somewhere along
the line you are going to produce carbon dioxide. In addition, there are
two main problems with the direct methanol cell — the reactions are
slow and the membrane is permeable to methanol, so you have a loss of
power and efficiency.”
To remedy the slow reactions, a catalyst is used. In the majority of cells,
this catalyst is platinum. “However, platinum is very expensive,”
Dr. Pickup said. Finding a more effective catalyst is another aspect of
his research. Recently, most of the funding Dr. Pickup’s group has
received is directed toward the modification of the membranes to stop
the methanol from crossing. “The Genesis Group has filed a patent
application on this modified membrane which basically blocks the permeable
‘holes,’” Dr. Pickup said.
Despite the advancements with the direct methanol cells, the PEM cell
still remains the primary fuel cell in use and is the most commercialized.
“The market at the moment is fairly small, restricted primarily to
stationary power, vehicles, and consumer electronics. But that is increasing
rapidly as they (the fuel cells) become better and cheaper, ” he
said.
Over time, Dr. Pickup has had the assistance of several graduate students. Many of these students have taken positions with various companies throughout North America, continuing to work in the field of fuel cell research. With so many superior minds working in this field, it is only a matter of time before the general population comes to rely on fuel cells as a primary source of electrical energy.
