(410e) Study of Photocatalytic Activity of Nano Organic Hybrid Materials (NOHMs) for Photoelectrochemical Reduction of CO2

A promising opportunity space for novel class of colloidal catalysts has emerged from recent advances in the synthesis of colloidal nanomaterials in which the composition of the inorganic core as well as the organic ligand shell can be precisely tuned. The prospect of tailoring the ligand shell, for optimized interaction with the surrounding fluid and the surface of the colloid, for catalytic conversion is particularly promising for photocatalytic reactions. We have investigated a new class of hybrid colloidal photocatalysts with combined functionality to capture CO₂ and convert it to liquid fuels. The photodriven CO₂-to-fuels reaction has profound technological implications as a prospect to harvest vast solar energy resources, capture CO₂ and store the energy in form of a liquid fuel. Scientifically, the photoreduction of CO₂ involves a complex interplay of coupled sub-processes including CO₂ transport to and adsorption on the catalyst surface, light absorption, proton-coupled multi-electron transfer, selectivity, and material stability.The photoelectrochemical reduction of CO₂ leads to various â??value-addedâ?? products including methane, olefins, methanol, ethanol, formaldehyde, formic acid, formate, and carbon monoxide. Whereas access to novel colloidal nanoparticle catalysts has enabled advances in fundamental understanding of and control over their catalytic properties, progress towards deploying this know-how by integration with established CO₂ capture technologies (i.e., amine scrubbing) has lagged behind. We embraced this challenge as an opportunity study basic processing-structure-performance relationships of nano organic hybrid materials (NOHMs) applied to the photoelectrochemical reduction of CO₂.We will describe the colloidal synthesis the inorganic nanoparticle core comprised of titania and metal co-catalyst and the CO2-philic ligand shell. We will discuss our recent advances in understanding and controlling the composition, morphology, ligand exchange, optical absorption, and CO₂ chemical and physisorption capacity. We will relate structure and composition of the catalyst to the photocatalytic performance and will describe reaction products and conversion probed by gas and liquid chromatography.