Charge regulation through rare earth metal oxides for single-atomic/cluster Co-based electrocatalysts towards boosting oxygen reduction reaction

Single-atomic/cluster metal-based electrocatalysts (M-N-C) is one of the most promising non-noble metal catalysts for the oxygen reduction reaction (ORR), but their practical application is severely hindered by insufficient activity and durability. Herein, charge regulation through rare earth metal oxides (REMOs) for single-atomic/cluster metal based electrocatalysts is proposed for boosting ORR, in which the Co-based catalyst is taken as a representative considering its typicality and universality, and CeO 2 is selected as representative after systematic computational screening from more than 10 types of REMOs. As a result, a novel REMO-tailored M-N-C electrocatalyst (REMO-Co-N-C) has been successfully achieved, which demonstrates a remarkably increased activity and superior durability, namely a half-wave potential (E₁/₂) of 0.90 V and only a loss of 8 mV (E₁/₂) after 10,000 cycles. Moreover, in-situ experiments and matched theoretical simulations come together organically to clearly and directly reveal the origin and catalytic behavior of the proposed electrocatalysts. Namely the charge regulation through REMO for M-N-C can effectively modify the electronic structure of the M sites, accelerate the reaction rate, and enhance OH* desorption. This work offers a new insight for promoting M-N-C catalysts through REMO tailoring, that beyond the conventional use of d-block and p-block elements.