Cascade Reaction Regulated Electrochemiluminescence via Dual-Atomic-Site Catalysts

Single-atom catalysts (SACs), a novelkind of electrocatalystswith full metal utilization, have been developed as unique signalamplifiers in several sensing platforms. Herein, based on theoreticalprediction of the oxygen reduction reaction (ORR) mechanism on differentatom sites, we constructed dual-atomic-site catalysts (DACs), Fe/Mn-N-C,to catalyze luminol-dissolved oxygen electrochemiluminescence (ECL).Computational simulation indicated that the weak adsorption of OH*on a single Fe site was overcome by introducing Mn as the secondarymetallic active site, resulting in a synergic dual-site cascade mechanism.The superior catalytic activity of Fe/Mn-N-C DACs forthe ORR was proven by the highly efficient cathodic luminol ECL, surpassingthe performance of single-site catalysts (SACs), Fe-N-Cand Mn-N-C. Furthermore, the ECL system, enhanced bya cascade reaction, exhibited remarkable sensitivity to ascorbic acid,with a detection limit of 0.02 nM. This research opens up opportunitiesfor enhancing both the ECL efficiency and sensing performance by employinga rational atomic-scale design for DACs.

Automated summary

Based on theoretical predictions of the oxygen reduction reaction mechanism, dual-atomic-site catalysts Fe/Mn-N-C were constructed for catalyzing oxygen electrochemiluminescence. Computational simulation showed a synergic dual-site cascade mechanism that overcame the weak adsorption of OH* on single Fe site by introducing Mn as the secondary metallic active site. Fe/Mn-N-C DACs exhibited superior catalytic activity for oxygen reduction, surpassing the performance of single-site catalysts Fe-N-C and Mn-N-C.