August 21, 2013
The EDX tests showed that I succeeded in synthesizing two new catalysts. Running out of time left in my internship, I decided to only test these two new samples, as they had the best XRD patterns. I created two solutions from each catalyst – one to be applied to electrodes for single cell tests and one for oxygen reduction reaction (ORR) testing. A single cell test involves constructing a fuel cell with two electrodes, each with the catalyst applied, and one stock membrane. The fuel cell performance can then be monitored to produce an array of data, including a maximum power density. I began single cell tests by attempting to test a standard cell with a generic platinum catalyst. When I began my project, the postdoc helping me warned that high temperature fuel cells can be difficult to work with. True enough, two attempts at running a standard and a test of the first catalyst showed poor results.
Inspecting the membrane electrode assembly after the tests, I found that the high temperature (160° C) burned holes through the membrane in all three cases. After these failed tests I was running out of time, so I turned to ORR tests. I performed ORR on the first catalyst, but had no time to finish with the second catalyst or a standard. The postdoc working with me will complete the last two ORR tests himself and send me the results.
These nine weeks were a great experience for me. As it was my first time in a research lab, I learned the research process, from setting up project proposals to presenting research. I really enjoyed the work I did and it has made me interested in pursuing further research. I’m looking forward to next summer already.
July 16, 2013
James in the process of putting a sample into a tube furnace.
Since my last post, I have become much busier in the lab and chosen to test a platinum-iron nanoparticle alloy catalyst on carbon black in high temperature fuel cells. I will be testing different molar ratios of platinum to iron and comparing the performance to that of a pure platinum catalyst. I began by using a solution method to synthesize the alloy in three different ratios. Following synthesis, a postdoc helped me use a scanning electron microscope (SEM) to produce images of my sample on a micrometer scale. This allowed me to check the dispersion and homogeneity of my catalyst on the carbon. Next, I performed energy-dispersive x-ray (EDX) spectroscopy to analyze the elemental components of my three samples. Each sample had a lower platinum to iron ratio than I was going for, but can still produce meaningful performance test results.
Taipei 101 viewed from a market Jamese visited last weekend. Taipei 101, formerly known as the Taipei World Financial Center, is a landmark skyscraper located in Xinyi District, Taipei, Taiwan.
Following SEM imaging, I synthesized two new samples with the goal of increasing the platinum to iron ratio. I will run SEM/EDX imaging later this week to confirm the higher platinum content. Yesterday, I took x-ray diffraction (XRD) spectra of my samples. This was done to check if my synthesis method produced an actual alloy, or simply led to individual platinum and iron particles. Of my five samples, the last three I synthesized show good alloy formation. My next step is to perform oxygen reduction reaction (ORR) tests on my five samples. I will then take the sample with the best results and use it to assemble a fuel cell for performance testing.
Last weekend Heather and I rented bikes through Taipei’s bikeshare system and met with the Tapei Fixie Bike Club. We rode to an outdoor bike track and watched a skidding competition. Afterwards, we rode with the bike club to a night market, and around Taipei until the sky started to brighten. The next day, we went to a pool party, where we made some new friends, both local and international.
July 1, 2013
The Taroko Gorge National Park.
Last weekend, a postdoc from Heather’s lab took us to Hualien County, on the East Coat of Taiwan. There, we visited the Taroko Gorge National Park, and went on a short hike to a river. That night, we visited a night market in Hualien known for making mixed fruit juice smoothies. Apparently Hualien is the only area in Taiwan where these are sold, as other juicers don’t mix fruits. That Sunday, we visited a rocky beach, but couldn’t go in the water because the East Coast has dangerous rip currents.
This past weekend, our fellow Cal Energy Corps participant, Sofia, came to visit Heather and I from Hong Kong. We were all planning on going paragliding, but there were only two open spots so I went to visit Guandu Temple instead. After taking the MRT, I had to transfer to a bus, but I didn’t know which stop I had to get off at for the temple. I asked a man on the bus, and he told me in broken English that he would show me. He must have misunderstood me, because when he told me we were at my stop, I found out that I was at a water park, and had gone far past the temple! It was a hot day, so I decided to make the best of it and spent the afternoon exploring the Formosa Fun Coast water park, home of the largest water slide in Asia.
James standing next to the mass damper in Taipei 101.
On Sunday, we took Sofia up Taipei 101. We took a high speed elevator (it only took 37 seconds!) from the 5th to 89th floor, where we observed the city, saw the huge mass damper, and learned some of Taipei City’s history.
For the past two weeks in the lab, I have been practicing the methods for creating fuel cell electrodes. At the same time, I have been researching catalysts for oxygen reduction that could potentially replace platinum in high temperature proton exchange membrane fuel cells (PEMFCs). Once I decide on a catalyst, I will synthesize and apply it to an electrode using the techniques I’ve learned. Hopefully I will be able to get started on my project this week!
June 17, 2013
The station where James’ runs performance tests for fuel cells.
I am working in the Advanced Materials Laboratory at the National Taiwan University under Dr. Kuei-Hsien Chen and Dr. Li-Chyong Chen. The lab is affiliated with both the Center for Condensed Matter Sciences at the National Taiwan University and Institute of Atomic and Molecular Science at Academia Sinica. It’s a large lab group, with around forty to fifty members working in four main subgroups: nitride materials, novel materials and graphene, solar energy, and hydrogen energy. Every Thursday the entire lab meets and a few people present progress reports. Additionally, subgroup meetings are held every other week.
Within the hydrogen energy subgroup, lab members conduct research on hydrogen production, hydrogen reforming, and fuel cells. I have been working with the fuel cell team, where I have spent the majority of these first two weeks reading articles and familiarizing myself with the concepts and methods employed in the lab. My objective is to learn enough about current fuel cell research to be able to design my own project for the summer.
The Dragon Boat Festival.
So far I have been learning some of the methods of creating electrodes for use in the fuel cell. It’s very interesting and exciting because I’m using state-of-the-art technology. Electrode synthesis begins with a small square of carbon-fiber cloth. A metal catalyst, such as cobalt, can be applied to the cloth by sputter deposition, a type of physical vapor deposition (PVD) that can deposit a thin film onto a substrate (the carbon cloth). Following that, carbon nanotubes (CNTs) can be grown on the carbon cloth by the microwave plasma enhanced chemical vapor deposition method (MPECVD). This machine takes the metal-coated carbon cloth and grows CNTs vertically up from the cloth surface. This could be imagined as growing grass on a square dirt lot, where each blade of grass represents a carbon nanotube. These CNTs increase the surface area of the electrode. Sputtering can then be used again to apply a catalyst, such as platinum, which will drive the redox reactions that occur on the electrodes when the fuel cell is in use. Finally, I have learned how to assemble a fuel cell and run performance tests.
The Maokong Gondolas.
Outside of the lab, Heather (the other Cal Energy Corps intern at Academia Sinica) and I have been exploring Taipei. Last weekend, we tried our hand at rowing on a dragon boat team and visited Fulong Beach to check out the sand-sculpting competition. That Wednesday, we had the day off work to celebrate the Dragon Boat Festival by eating zongzi, rice dumplings wrapped in leaves, and watching dragon boat races. The following weekend, we took the MRT (the Taipei equivalent of BART) to the Taipei Zoo, and then took a gondola up to Maokong, a town well-known for it’s tea. So far I’ve really enjoyed my time in Taipei, and I’m getting better with chopsticks every day.