POM‐based Electrocatalysts for Oxygen Evolution Reaction

Chapter 7 explores the significant impact of polyoxometalates (POMs) on the dynamic field of water oxidation electrocatalysis, also known as the oxygen evolution reaction (OER). POMs exhibit fascinating redox properties, diverse compositions and structures and remarkable versatility, making them pivotal players in the advancement of efficient OER electrocatalysts and a key element in the shift towards green energy conversion. This chapter serves as a valuable resource, offering insights into the application of POMs in OER, ranging from mechanistic studies using water-soluble POM platforms to investigations focused on the electrochemical characterization of POM-based nanostructured materials. To facilitate understanding, Chapter 7 is intuitively divided into five main sections. The first section provides an introduction to the fundamental aspects of the OER process, including the description of standard performance indicators. The second section delves into research on pure POMs, exploring their roles in both homogeneous and heterogeneous catalytic systems and paying particular attention to mechanistic aspects. Moving forward, the third section examines the OER electrocatalytic behaviour of various POM-based nanocomposites. These composites involve the integration of diverse POM clusters with other materials, such as nanocarbons, metals, metal (hydro)oxides and metal–organic frameworks (MOFs), in search of synergistic enhancements. In Section 7.4, we showcase highly promising OER electrocatalysts derived from POM-containing precursors. In these cases, the original POM structure is sacrificed to achieve improved dispersion of metals while still maintaining high catalytic activity. Lastly, the concluding remarks summarize the most significant findings and provide an overview of the most effective approaches for synthesizing efficient noble-metal-free electrocatalysts for water oxidation.