(583ak) The Mechanism of Solar Thermochemical CO2 Splitting On CeO2

Authors: 
Arifin, D., University of Colorado Boulder
McDaniel, A. H., Sandia National Laboratories
Weimer, A. W., University of Colorado Boulder



Building a sustainable energy-economy that can ensure our energy security and mitigation of anthropogenic climate change are two of the most important issues that challenge us in the 21st century. Our over reliance on fossil fuels, a non-renewable energy source that is geographically distributed inhomogenously, often fuel geopolitical conflicts. Producing CO renewably as feedstock for synthetic fuel production by splitting CO2 in a solar-based thermochemical process is an attractive solution to these 21st century challenges

Due to the high thermal stability and rapid exchange kinetics, ceria is a favored material for the solar thermochemical carbon dioxide splitting process.  In order to maximize the solar-to-CO conversion efficiency, an understanding of the mechanistic pathway and a detailed engineering model of the surface mediated CO2 splitting process is necessary.

In this work, we report the results of a numerical and micro-kinetic analysis that separates experimental artifacts from material-specific CO production behavior yielding high quality fits to experimentally determined CO production rates over the entire reaction time domain. The results of this study show that a complex surface phenomenon where temperature-dependent site blocking and mechanism transition occurs at the different oxidation temperatures.

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