NANOSTRUCTURED METALS FOR ELECTROCHEMICAL CARBON DIOXIDE REDUCTION

摘要

Due to rising energy demand and evidence of the environmentalrneffects of CO_2 emissions, much research has focused on producing andrnstoring energy from renewable sources. An efficient and selectivernprocess for the conversion of CO_2 to CO or other reduced productsrncould allow for the widespread production of liquid fuels. Coupledrnwith renewable energy sources, these processes could help solve thernlarge scale storage issue of renewable energies while creating a carbonrnneutral energy source easily integrated into the current energyrninfrastructure.To date, researchers have identified several bulkrnmetal catalysts such as Cu, Ag, Au, and Zn that are able to reduce CO_2rnelectrochemically in aqueous electrolytes albeit requiring significantrnenergy from an external source (i.e. overpotential) to drive the reactionrnNanostructured catalysts are of great interest for CO_2 to COrnconversion due to their high catalytic surface area and uniquernproperties relative to their polycrystalline counterparts. In thisrnpresentation, we will discuss our recent discovery of a highly activernnanoporous Ag electrocatalyst, which is able to reduce CO_2rnelectrochemically to CO in a highly efficient and selective way. Notrnonly the porous structure creates an extremely large surface area forrncatalytic reaction, but also the curved internal surface generates a largernnumber of highly active step sites for CO_2 conversion, resulting in anrnexceptional activity that is over three orders of magnitude higher thanrnthat of the polycrystalline counterpart at a moderate overpotential of