The Functional Role of Disordered Metal Oxides from Active Catalysis to Biological Metabolism

Abstract

It has been observed by many authors that highly active electrocatalysts are frequently “disordered” or “amorphous” in nature. The correlation between this lack of order and functionality is highly debated, with researchers still questioning if this structural property is a simple coincidence of the material preparation method, or if this lack of order has an important functional role for these catalysts. Using metal oxides as an example, how amorphous and disordered metal oxides can react by fundamentally different pathways are explored from more ordered forms with very similar bonding and redox states. The distinction between amorphous, disordered, and crystalline materials is reviewed in different characterization methods and suggests how these material characteristics fundamentally change the reactivity of these materials beyond surface area effects. How disorder can change the underlying thermodynamic stability of a material is explored, which in turn impacts redox potential, proton‐transfer, and electron‐transfer properties. It is these fundamental properties that govern the electrocatalytic activity and microbial metabolism of these materials. It is further argued that understanding the amorphous and disordered state of materials may be key to understanding a range of catalytic reactions; from clean energy reactions to the biological systems that underpin life's existence.