Resnick Institute


James Blakemore and Sam Johnson
James Blakemore & Sam Johnson

Resnick Fellows Present Research at International Solar Fuels Meeting in Sweden

Summer 2015 - Written by Resnick Prize Postdoctoral Scholar James Blakemore and Resnick Fellow Sam Johnson

In April 2015, we had the tremendous opportunity to travel to Uppsala, Sweden for the 1st International Solar Fuels Conference. This large and vibrant meeting brought together 500 researchers from around the globe in the beautiful university town of Uppsala, Sweden. As Fellows of the Resnick Institute, we travelled to the meeting to present our original research, hear the latest developments in the field, and network with other scientists that are active in the area of solar fuels. The meeting spanned a week, including both the main meeting and a satellite meeting for young researchers.

Hosted by the Swedish Consortium for Artificial Photosynthesis (SCAP), the meeting was highly interdisciplinary. SCAP researchers span natural and artificial photosynthesis, with the idea of “learning from Nature” to achieve efficient artificial processes for solar-energy conversion. The meeting was similarly organized, including topics ranging from photosynthesis in algae for biofuel production to the latest efforts to incorporate catalytic materials with solid-state semiconducting light absorbers. The colorful program was composed of more than twenty plenary talks and three thematic parallel sessions that showcased the wide variety of work centered on the goals of solar fuel production.

The wide-ranging program provided opportunities for our community to discuss current challenges in solar fuel production. For example, development of light-absorbing materials that provide the performance needed to make solar hydrogen production economically feasible are still restricted to just a few candidates. Along the same line, no new acid-stable water-oxidation catalysts have been disclosed that would be suitable for device integration. This leaves the community with only the option of using costly iridium-based catalysts for the anode of a future device.

Molecular catalysis is one rational path to overcoming this challenge, as well-defined catalysts can be more easily studied for mechanistic insights and performance optimization. However, homogeneous, molecular catalysts continue to lag behind their heterogeneous cousins in performance, leading some to dismiss them as impractical. In fact, disagreements even remain about how to properly rate the performance of molecular systems due to questions of mechanism, electrochemical cell design, and cell conditions.

Our work at Caltech is related to this area of vigorous discussion. James gave a talk on electrode-immobilized molecular catalysts to an audience of over 100 graduate students and postdoctoral scholars at the young-researchers meeting. Both of us gave posters at the main meeting, which were well received. However, Sam was selected for an extra opportunity: from among the hundreds of posters at the main meeting, hers was chosen as a special “flash” poster presentation. Sam discussed her work on modeling mechanisms of selective CO2 reduction catalysis.

For the past nine months, we have been collaborating on a new project topic that is currently of high interest in the solar fuels community due to the challenges mentioned above: how to stably immobilize selective molecular catalysts on (photo)electrode surfaces. In particular, our research focuses on the molecular catalysts that transform the CO2 to useful fuels at electrode surfaces. Immobilization brings molecular catalysts closer to device integration, and also simplifies some aspects of the electrochemistry, allowing a route to improved understanding of catalyst performance. As a Resnick Prize Postdoctoral Scholar, James’s research focuses on synthesizing and studying such catalysts on electrodes. As a Resnick Graduate Fellow, Sam models these systems, including some of James’s, to understand mechanisms and failure modes. This collaborative work, funded by the Resnick Institute, is already yielding new projects that aim to stably immobilize selective molecular catalysts on semiconductors like silicon.

Although it was James’s first time to Sweden, he was quite familiar with the work of SCAP already. For Sam, it was a chance to return to Sweden, as she spent three and a half months there in 2014, collaborating with Dr. Petter Persson at Lund University. Thus, for both of us, it was a truly excellent opportunity to learn about the latest research, as well as meet with old friends.

In addition to the academic program, we were able to explore the city and culture of Uppsala. (Of course!) We visited the local cathedral and castle, both of which have big historical significance. For example, the kings and queens of Sweden are still crowned in the cathedral to this day. The formal conference dinner was held in the halls of the Uppsala castle, and featured uniquely Swedish entertainment: a Carl von Linné (Carolus Linnaeus) impersonator cracking jokes about his accomplishments as a scientist and naturalist, sharing anecdotes from the history of Uppsala, and giving the decidedly international crowd a lesson in Swedish humor.

To summarize, we thank the Resnick Institute for their support of our recent visit to Sweden for the International Solar Fuels Meeting. The invigorating scientific and social atmosphere has left us excited to be back at Caltech, and working together to make progress in our research. Let us know if you want to hear more about the meeting!