Steven Torrisi, Harvard University

Photo of Steven Torrisi

Novel photo-active catalysts that can harness sunlight to power the CO2-reduction reaction are a crucial component for future carbon-neutral energy production and energy-efficient industrial processes. Scalable CO2-reduction photoelectrocatalysts must satisfy a stringent set of criteria, such as stability under operating conditions, product selectivity, low overpotential, efficient light absorption and appropriate band edges. Two-dimensional materials offer tunability, high specific surface area and potential for heterostructuring, thus providing a fresh landscape of candidate catalysts. From a set of recently identified promising bulk CO2 reduction photoelectrocatalysts, we screen for and identify candidate two-dimensional monolayers of these materials and study their stability and electronic/reactive properties. For the stable candidates, we verify that the band gaps lie in the visible light spectrum and the band edges are suitable for CO2 reduction and compute the theoretical overpotential of several representative reaction pathways. We find that the reactivity and selectivity biases towards CO production, resembling noble metal catalysts like Ag and Au, with potential applications to the production of hydrocarbons via the Fisher-Tropsch process. We thus expand the chemical space of target structures for CO2 photoreduction and identify SiAs, ZnTe and ZnSe monolayers as targets for future experimental and theoretical investigation.

Abstract Author(s): Steven B. Torrisi, Arunima K. Singh, Joseph H. Montoya, Kristin A. Persson