Single-atom catalysis for carbon neutrality

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_(2) emissions and develop sustainable clean energy can be adopted.Notably,these are crucial for the synthesis of advanced single-atom catalysts(SACs)for energyrelated applications.In this review,we highlight unique SACs for conversion of CO_(2) into high-efficiency carbon energy,for example,through photocatalytic,electrocatalytic,and thermal catalytic hydrogenation technologies,to convert CO_(2) into hydrocarbon fuels(CO,CH_(4),HCOOH,CH_(3)OH,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_(2) conversion,water splitting to H2,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.