A Review on Solid-Solid Heterogeneous Interfacial Interaction in Electrocatalytic Conversion of Inorganic Molecules

In electro-catalytical conversion of inorganic molecules, solid-solid interfaces universally form during the synthesis of electrocatalysts and the preparation of electrodes; they can also form during the electrochemical process of charging or discharging. In this feature article, the various solid-solid interfaces in porous electrodes are covered. In particular, by referring to studies in our group, a concept of specific interfacial area is proposed, which provides an index to evaluate the solid-solid interfacial interaction at meso-scale; furthermore, two types of solid-solid interfacial interactions at micro-scale, namely the Van der Waals interface and the covalent interface, are discussed and compared in terms of their efficiency in electrocatalysis; empirical yet general guidelines for construction of solid-solid heterogeneous interfaces which support efficient interfacial electron transfer and electrocatalytic stability are provided accordingly. Last but not least, the role of interfacial electron delocalization behaviors in modulating the local electronic structure of the active sites and catalytic activity is emphasized. With this, this feature article aims to showcase the importance and charm of solid-solid heterogeneous interface in regulating the efficiency of electrocatalysis.