Single-atom catalysts:The role of intrinsic intermediate

摘要

MetalN-C single-atom catalysts(SACs)have emerged as alternatives to platinum for catalyzing the otherwise sluggish oxygen reduction reaction(ORR)[1].Fe-N-CSACs rank among the most promising candidates[2],of which the active center is proposed as a carbon-hosted FeN4 moiety with the Fe atombeing single-atom(SA)state(Fig.1a).Such a well-defined configuration renders Fe-N-C a model catalyst to study ORR in an atomistic way.The catalytic process on SA Fe of the FeN4 center has been elucidated by using the modern in silico modeling and structural characterizations.Despite the agreement of the key role ofSAFe in the literature,it is still controversial howSAFe boosts ORRgiven that the predicted potentials calculated using the FeN4 moiety deviate from experimental ones,hampering further development of ideal SACs.Therefore,it is imperative to get deeper understanding of the reaction pathway while considering the dynamic ORR process.