Design of bimetallic catalysts and electrocatalysts through the control of reactive environments

Publication date: Available online 6 January 2020Source: Nano TodayAuthor(s): Yung-Tin Pan, Hong YangAbstractBimetallic nanocatalysts often exhibit enhanced performances, which are directly related to the specific atomic arrangements of the two metal elements on and near surface. It is thus important to control not only the overall but also, perhaps more critically, near surface compositions and structures. While many approaches have been developed for making bimetallic nanostructures with predetermined overall compositions, the control of surface structures with a high degree of accuracy is still a challenge. With the recent development of in situ tools such as environmental transmission electron microscopy (ETEM), dynamic structures under variable temperatures and reactive atmospheres can be studied quantitatively, laying the foundation for improved precision design of specific surface structures for catalysis. Herewith, we provide an overview of factors governing the dynamic processes of bimetallic restructuring. We first discuss the surface energetics of shaped bimetallic nanoparticles under gaseous environments, followed by examining the transformation of alloy nanoparticles into intermetallics and the key aspects in the preparation of intermetallic surfaces. Diffusion-controlled restructuring process is then presented, including the major recent developments in controlling the surface composition and formation of hollow structure from the Kirkendall process. Finally, we...
Source: Nano Today - Category: Nanotechnology Source Type: research