Single-atom electrocatalysts forwater splitting

Abstract

The amount of energy that has being required to keep the well-being of our society is increasing continuously imposing an urgent need for renewable and less pollutant alternative energy sources to fossil fuels, whose consumption in internal combustion engines and electric power plants are responsible for unprecedented atmospheric pollution, particularly concentrated in large cities. Another consequence seems to be the general increase of temperature of the planet leading to climate changes and catastrophic extreme events. Thus, the possibility of reserves depletion and global environmental issues associated with its use are prompting the search for clean renewable energy sources, as well as the development of efficient and more robust energy storage systems. The most promising one for such a purpose is based on the splitting of water in a photosynthetic system to store the energy of Sun as hydrogen and oxygen. In order to realize such a technology, new more efficient electrocatalysts for oxygen and hydrogen evolution reaction based on single-atom catalysts, especially designed to exploit the maximum potentiality of the elements, are being developed, fueled by increasingly powerful theoretical modelling and characterization tools, thus paving broad roads towards a bright and sustainable society. The main advancements for preparation and characterization of such novel strategic materials are considered in this account. Furthermore, atomic scale modelling based on density functional theory is also discussed in the context of the unique electronic structure that leads to superior catalytic activity, highlighting its potential to advance this important scientific field.