Non-bonding modulations between single atomic cerium and monodispersed selenium sites towards efficient oxygen reduction
Currently, dual atomic catalysts (DACs) with neighboring active sites for oxygen reduction reaction (ORR) still meet lots of challenges in the synthesis, especially the construction of atomic pairs of elements from different blocks of the periodic table. Herein, a “rare earth (Ce)-metalloid (Se)” non-bonding heteronuclear diatomic electrocatalyst has been constructed for ORR by rational coordination and carbon support defect engineering. Encouraging, the optimized Ce−Se diatomic catalysts (Ce−Se DAs/NC) displayed a half-wave potential of 0.886 V vs. reversible hydrogen electrode (RHE) and excellent stability, which surpass those of separate Ce or Se single atoms and most single/dual atomic catalysts ever reported. In addition, a primary zinc-air battery constructed using Ce−Se DAs/NC delivers a higher peak power density (209.2 mW·cm −2 ) and specific capacity (786.4 mAh·g Zn −1 ) than state-of-the-art noble metal catalysts Pt/C. Theoretical calculations reveal that the Ce−Se DAs/NC has improved the electroactivity of the Ce−N 4 region due to the electron transfer towards the nearby Se specific activity (SA) sites. Meanwhile, the more electron-rich Se sites promote the adsorptions of key intermediates, which results in the optimal performances of ORR on Ce−Se DAs/NC. This work provides new perspectives on electronic structure modulations via non-bonded long-range coordination micro-environment engineering in DACs for efficient electrocatalysis.
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