Developing sustainable, fossil-free pathways to produce fuels and chemicals of global importance play a major role in reducing carbon dioxide emissions while providing the feedstocks needed to make the products we use on a daily basis.
“Electrocatalysis plays a central role in clean energy conversion, enabling a number of sustainable processes for future technologies. As electricity from renewable energy becomes cheaper and cheaper, it increases the motivation to use it for much more than we do today,” explains Professor Ib Chorkendorff, Director of V-SUSTAIN (the VILLUM Center for the Science for Sustainable Fuels and Chemicals), who will be a speaker at the upcoming Catsense Summer School on “Catalysis and Nanoparticles”, 11 - 14 September 2017 in Leuven Belgium. “Earth’s atmosphere provides a universal feedstock of water, carbon dioxide, and nitrogen, which can potentially be converted into important fuels and chemicals via electrochemical processes coupled to renewable energy if electrocatalysts with the required properties can be developed.”
Schematic of a sustainable energy landscape based on electrocatalysis, © Seh et al., Science 355, eaad4998 (2017)
This review in Science Magazine (http://science.sciencemag.org/content/355/6321/eaad4998 ), discusses design strategies for state-of-the-art heterogeneous electrocatalysts and associated materials for several different electrochemical transformations involving water, hydrogen, and oxygen. It clarifies the trends, serving as a guide to new catalyst development while highlighting key gaps that need to be addressed. It offers a framework to emerging clean energy reactions such as hydrogen peroxide production, carbon dioxide reduction, and nitrogen reduction, where the development of improved catalysts could allow for the sustainable production of a broad range of fuels and chemicals.
Electrochemical energy conversion. Schematic showing electrochemical conversion of water, carbon dioxide, and nitrogen into value-added products (e.g., hydrogen, hydrocarbons, oxygenates, and ammonia), using energy from renewable sources. The combination of theoretical and experimental studies working in concert provides us with insight into these electrochemical transformations and guides the development of the high-performance electrocatalysts needed to enable these technologies. © Seh et al., Science 355, eaad4998 (2017)
Crucial to enabling this vision is the development of improved electrocatalysts with the appropriate efficiency and selectivity for the chemical transformations involved.
There are generally two strategies to improve the activity (or reaction rate) of an electrocatalyst system:
- increasing the number of active sites on a given electrode (e.g., through increased loading or improved catalyst structuring to expose more active sites per gram) or,
- increasing the intrinsic activity of each active site.
These strategies are not mutually exclusive and can ideally be addressed simultaneously, leading to the greatest improvements in activity.
Schematic of various catalyst development strategies, which aim to increase the number of active sites and/or increase the intrinsic activity of each active site., © Seh et al., Science 355, eaad4998 (2017)
Read the full article at http://science.sciencemag.org/content/355/6321/eaad4998