Prepping for a Mission to Mars

Joshua Crawford, a PhD candidate in Chemical Engineering at Columbia University, recently received a NASA Space Technology Graduate Research Fellowship. He is the first PhD student in the Department of Chemical Engineering at Columbia to win this prestigious fellowship, which is worth $336,000 over four years. This award will support Crawford’s research into the fundamental chemical processes that govern the conversion of carbon dioxide into more useful materials.

Crawford works with faculty advisor Juliana Carneiro, an assistant professor of chemical engineering whose research group focuses on creating catalytic systems to enable the valorization of readily available resources such as waste, carbon dioxide, water, and air. Her group specializes in using thermo-electrochemical reactors that operate at intermediate temperatures of 300-600 C. This work supports a circular and sustainable chemistry framework and is part of the Lenfest Center for Sustainable Energy (LCSE) and the Columbia Electrochemical Energy Center (CEEC).

At Columbia, Crawford is aiming to make a mission to Mars a reality.

The astronauts who visited the Moon took all of their supplies with them, but that's not feasible for a Mars mission. What resources will technology based on your project use as feedstocks, and what products will it provide? 

I hope to use atmospheric CO2 on Mars’ surface to make products that are essential for life, like water and molecular oxygen. I’m working to make materials like methane, carbon monoxide, and hydrogen, which can be used to make fuels and other complex hydrocarbons.

Your work centers on using solid-state protonic ceramic electrolysis cells (PCECs). What are PCEs?

PCECs are a type of electrolyzer that operate at an intermediate temperature (300-600ºC). They use an electrical current to transform materials by transferring protons from one sample to another. 

In terms of electrochemistry, this happens through the reduction of species at one electrode (e.g. CO2 at the cathode to our desired products) and oxidation of species at the opposing electrode (e.g. H2O at the anode). By applying a bias voltage in the intermediate temperature range, PCECs are able to conduct protons through their electrolyte to complete the electrochemical circuit and help drive electrolysis.

What aspect of the technology are you working on? 

I’m working to improve this process by developing methods to more precisely design the catalysts used in this process.

I’m interested in making use of different synthesis methods that can allow us to create CO2 reduction catalysts with a specified shape, size, and composition. Analyzing the effects of these parameters will allow me to build an understanding on how efficiency and selectivity can be achieved during reaction to create valuable reduced products like methane or synthesis gas.

The performance of our catalyst is closely linked to properties like its geometry, electronic structure, and support interactions, so investigating these well-defined, model nanocrystal catalysts can hopefully bring us closer to resolving the role of the catalyst active site during CO2 reduction to define the reaction mechanism of reduction. This captures my motivating question: How can we achieve tunable selectivity while maintaining catalyst activity and stability during CO2 reduction? 

What motivates you to do this work? 

I think it’s exciting that the efforts of this work probe fundamental questions associated with transforming carbon dioxide into other materials through CO2 reduction in these relatively new electrochemical systems (PCECs). 

By answering these questions we can hopefully enable more efficient conversion of CO2 not only for applications for NASA but also for various industries/sectors globally where CO2 emissions and mitigation remains a challenge. 

For this reason, I’m excited to work with NASA given its strong track record of disseminating scientific breakthroughs from space technology to everyday use-cases, such as water purification systems, wireless electronics, and even the portable computer.