(677d) The Water Splitting Kinetics of Two-Step Solar Thermochemical Process With CeO2

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

Projected growth in global population and continued industrialization of developing countries will increase total world energy consumption by 50% in the next three decades. This increased demand for energy will be largely met by increased fossil fuel consumption, thereby increasing anthropogenic carbon in the atmosphere and further fuelling geopolitical conflicts over control of dwindling energy resources. Producing H2 renewably by splitting H2O in a solar-based thermochemical process is an attractive solution to both of these 21st century problems.

Due to the high thermal stability and fast kinetics, ceria is a favored material for the solar thermochemical process.  In order to maximize the solar-to-hydrogen conversion efficiency, an understanding of the mechanistic pathway and a detailed engineering model of the water splitting process is necessary.

In this work, we report the results of a numerical analysis that separates experimental artifacts from material-specific H2 production behavior yielding high quality fits to experimentally determined H2 production rates over the entire reaction time domain. The results of this study show that the water splitting process is a surface mediated process analogous to a homogenous reaction, with low apparent activation energy.