Defect engineering of nonprecious metal based catalysts for oxygen evolution reaction

Abstract

As a branch of catalysis, electrocatalytic energy conversion reactions have been extensively studied and widely applied in industry. Hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are the most common electrocatalytic reactions, which have been utilized in water splitting, fuel cells, and zinc-air batteries, and so on. The ideal benchmark catalysts for these reactions are noble metal based catalysts, like platinum (Pt), ruthenium (Ru) and iridium (Ir). However, their high cost and instable catalytic performance during long-term usage make it impractical to use them on a massive scale. To develop a commercially affordable electrocatalyst with a promising activity, a series of catalysts originated from the defective two-dimensional (2D) nanomaterials emerged, such as carbon, transition metal oxides and transition metal dichalcogenides. Their atomic thickness, large lateral size, high surface-to-volume atom ratio and large specific surface area render them promising for numerous applications, such as (electro)catalysis, electronics, sensors, energy storage and conversion, and so on. Meanwhile, the defects existed on these 2D materials can significantly tailor their intrinsic physical properties even in an extremely low concentration, and thus great efforts have been devoted into the artificially surface defect engineering. But there are three major challenges that need to be