At present, renewable energy technologies are developed to solve the current energy and environmental crisis. Electrocatalysts play a crucial role in key energy conversion reactions, such as oxygen reduction for fuel cells and metal-air cells, hydrogen evolution and oxygen evolution for electrolysis of water. Although great progress has been made in the last decade due to the rational design of electrocatalysts at nanoscale, further development in this field requires the precise regulation their electronic/atomic structure, which is a huge challenge.<br/>Cation exchange reaction involves replacing cations in a host lattice of nanocrystals with desired cations. Using nanomaterials with well-tuned size and morphology as templates, cation exchange conversion can overcome the difficulties of controlling the composition, size and shape of final products in traditional synthesis methods. These characteristics make cation exchange a very attractive synthetic tool for the manufacture of high-quality electrocatalysts.<br/>We use the ion-exchange strategy as a particularly powerful tool for fine-tuning the atomic/electronic structure of electrocatalysts. Specifically, preservation or reorganization of the shape/facets in parent nanocrystals via cation exchange allows for achievement of favourable atomic arrangement, which provides a great opportunity for tuning adsorption/desorption of intermediates during electrocatalytic reactions. Moreover, the in-situ incorporation of dopants and the formation of defects during cation exchange ensures the precise control of doping stoichiometry and defect formation without damaging the host crystals, which is very effective for improving the conductivity and intrinsic activity of electrocatalysts. In addition, cation exchange allows for lattice strain modulation, which adds a new degree of freedom to manipulate the properties of electrocatalysts. Cation exchange adds flexibility to the atomic/electronic structure engineering of electrocatalysts. Through this strategy, the intrinsic and surface activity of electrocatalysts can be enhanced and show great potential in the design of new energy conversion devices, such as water decomposition devices and metal-air batteries. We believe that cation exchange reactions provide new insights and opportunities for the rational design of new generation of electrocatalysts.

Engineering atomic/electronic structure of transition metal oxide by cation exchange: Application in elecrocatalysis

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.