Hydrogen fuel cells hold promise for commercially viable, zero-emission electric vehicles. Proton exchange membrane fuel cells (PEMFCs) are the technology of choice to reach this goal but face significant challenges for widespread adoption.
One of the hurdles is the cost of the cathode catalyst layer, the part of the fuel cell that enables the electro-chemical reaction leading to energy generation. Platinum is the most effective material for catalyzing this reaction—but it is also extremely expensive.
Byron Gates and his team at Simon Fraser University (SFU) set out to find a way to use the least amount of this precious metal possible without sacrificing performance. At the same time, their solution would need to be compatible with existing manufacturing processes.
“Theirs is the first study to show the use of cathode catalyst layers containing electrodeposited, high surface area, mesoporous platinum in PEMFCs’’
“There are already PEMFC products being produced, so we were trying to come up with commercially available materials and scalable processes that could be transferred to industry,” explains Dr. Gates, Associate Professor and Canada Research Chair, Tier II in Surface Chemistry, and Head, Centre for Soft Materials in 4D LABS at SFU.
“The nanoparticles of platinum catalysts are ideally supported on pre-prepared inks that have both electrically and ionically conductive pathways,” Gates explains. “But in existing catalyst products widely used by industry, many of the particles are inactive because they’re not within a conductive pathway so you’ve got an expensive catalyst that is not helping you achieve your goal of obtaining more power out of the fuel cell.”
Dr. Gates’ then-doctoral student, Michael Paul, took a different approach to preparing his catalyst ink that included using electroplating, a long-established industrial process, to deposit platinum onto catalyst support layers. “We put the catalyst right where it needs to be with electrodeposition, at the same time, creating a really porous structure,” says Dr. Paul. “It created a surface where the catalyst would have the most efficient utilization possible.”
Their study showed that the catalyst layers were about twice as efficient as conventional platinum catalysts, with a higher utilization of the precious metal. But this work did not stop with just preparing the catalyst layer. “Mike paid attention to how to translate this technology to industry,” Dr. Gates says. “He took the electroplated layers and transferred them into a fuel cell. It was quite remarkable – he was able to not only make the catalyst, but to characterize it, put it into a fuel cell, and test it within a relatively short period of time at minimal cost. All this was only possible with help from CMC.”
“That was one of the key things,” Dr. Paul says. “CMC’s support through their micro-nanotechnology (MNT) program and MNT Award gave us access to training and a wide range of tools such as a cleanroom, characterization facilities, and testing facilities throughout the study.” The entire workflow of fabrication, characterization, and testing was made possible under one roof at 4D LABS at SFU. “We would not have been able to access these state-of-the-art facilities without CMC support.”
As far as the researchers know, theirs is the first study to show the use of cathode catalyst layers containing electrodeposited, high surface area mesoporous platinum in PEMFCs. This was reinforced earlier this year when their publication in Nature Scientific Reports was ranked among the prestigious journal’s Top 100 downloaded chemistry papers for 2019.
Their groundbreaking research has also led to a commercial partner interested in their approach. But equally important, Dr. Gates says, is the experience and expertise gained by his former student. Now a PEMFC component R&D engineer with one of the world’s few PEMFC manufacturers, Dr. Paul will be applying his knowledge in a manufacturing setting. Fittingly, his job is to facilitate the interface of advanced research and materials with industrial development.
“Fuel cells combine aspects of engineering, chemistry, materials science, and sustainable development that are exciting to work on,” he says. “It offers opportunities for outside-of-the-box thinking and research, which interests me the most.”
Photo Credit: Byron Gates