Artificial Photosynthesis: Improving the electrocatalyst for proton reduction in water

Hello, my name is Trevor Chang, and I am a rising senior chemistry major. I have done research with Dr. McNamara beginning this year, and am excited to continue it this summer.

According to the U.S. Energy Information Administration, in 2011, 79.8% of the United States’ energy production was composed of fossil fuels. This is a major issue that needs to be addressed because global warming and rising sea levels are two consequences of increased pollution from fossil fuel energy production. Energy production from fossil fuels on this magnitude will only result in more severe climate changes. In addition to increased pollution, the rate of consumption of current energy sources is expected to increase. Finding an alternative renewable energy solution has never been more urgent because based on 1998 consumption rates, the global oil resources will be exhausted within the next century. The growing need for energy will only exhaust these resources faster.

This summer I will be working with Dr. McNamara to develop an effective electrocatalyst, composed of a metal center and redox active ligands, for operation in water to reduce protons in a system called Artificial Photosynthesis, or AP for short. The goal of AP is to generate hydrogen gas from sunlight because enough sunlight hits the Earth in one hour to power the Earth for an entire year. As a sustainable, renewable energy source, hydrogen gas has the potential to change pollution trends. The role of the catalyst is to accept electrons excited by the sunlight and use them to reduce protons from water to hydrogen gas. However, current metal catalysts used in AP contain rare earth metals such as platinum and palladium. While these are the best catalyst available, they are very expensive. Specifically, my goal will be to develop an electrocatalyst with an iron center, the most abundant (cheap) earth metal. The major step in developing this catalyst is finding the appropriate redox active ligands that improve the efficiency of reduction, and one way Dr. McNamara and I propose to do that is to add electron withdrawing groups to the ligands. If they are added, electron density is pulled away from the metal center, causing the center to have a greater affinity for electrons, which should improve its efficiency.

Testing for successful synthesis of the metal electrocatalyst and effectiveness is done using various techniques and instruments that include NMR, electrochemistry, recrystallization, and x-ray diffraction. At the conclusion of the research, I hope to gain more knowledge in these techniques, as well as improvement in chemical synthesis and creative problem solving. Unfortunately during the school year, there is not much time to be in lab working on improving these skills, but I am glad for the chance to do much more this coming summer. If you are interested in hearing more, follow me this summer or email me at tychang@email.wm.edu!

Comments

  1. Wow, it is amazing that research is being conducted that has the potential to profoundly affect how the world uses its energy here at W&M! I hope that your work in artificial photosynthesis grows to the point where, and I am of course being hopeful, humans might be able to utilize photosynthesis within our bodies!