Single‐atom catalysis for carbon neutrality

Abstract

Currently, more than 86% of global energy consumption is still mainly dependent on traditional fossil fuels, which causes resource scarcity and even emission of high amounts of carbon dioxide (CO ₂), resulting in a severe “Greenhouse effect.” Considering this situation, the concept of “carbon neutrality” has been put forward by 125 countries one after another. To achieve the goals of “carbon neutrality,” two main strategies to reduce CO ₂emissions and develop sustainable clean energy can be adopted. Notably, these are crucial for the synthesis of advanced single‐atom catalysts (SACs) for energy‐related applications. In this review, we highlight unique SACs for conversion of CO ₂into high‐efficiency carbon energy, for example, through photocatalytic, electrocatalytic, and thermal catalytic hydrogenation technologies, to convert CO ₂into hydrocarbon fuels (CO, CH ₄, HCOOH, CH ₃OH, and multicarbon [C ₂₊] products). In addition, we introduce advanced energy conversion technologies and devices to replace traditional polluting fossil fuels, such as photocatalytic and electrocatalytic water splitting to produce hydrogen energy and a high‐efficiency oxygen reduction reaction (ORR) for fuel cells. Impressively, several representative examples of SACs (including d‐, ds‐, p‐, and f‐blocks) for CO ₂conversion, water splitting to H ₂, and ORR are discussed to describe synthesis methods, characterization, and corresponding catalytic activity. Finally, this review concludes with a description of the challenges and outlooks for future applications of SACs in contributing toward carbon neutrality.