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

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 21^st 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 21^st 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.