(ECS Carl Wagner Memorial Award) Free Electrons to Molecular Bonds and Back - The Dark Side of Solar Fuels and Chemicals

Abstract

The rising share of renewable electricity in power generation is testament to the increasing importance of solar/wind-electric routes to harvest sun light in form of free electrons. While some electricity will always be used directly or stored short-term in batteries, an increasing portion of it calls for direct conversion into valuable molecular solar e-fuels and e-chemicals, possibly followed by a later re-conversion into power. These “dark” e-conversion processes are made possible by electrocatalysis at electrified solid-liquid interfaces, coupled to mass and charge transport in the electrolyte bulk. New catalyst and ion conducting materials along with an understanding of the origin of reaction kinetic and transport barriers are needed for the design of ever more efficient, electrochemical interfaces in galvanic and electrolytic devices for the production and use of fuels and chemicals.This presentation reports on a few examples of advances in our design and understanding of electrocatalytic materials, interfaces and mechanisms relevant to the conversion of electricity into energy or value-added molecular compounds. Experimental approaches covered range from in-situ/operando spectroscopic, microscopic, scattering and spectrometric techniques at the microscale to new diagnostic tools and analyses of mass transport at the macroscopic device level. Examples include generation and use of green hydrogen and the conversion of CO2. Figure 1