Facet Strain Strategy of Atomically Dispersed FeNC Catalyst for Efficient Oxygen Electrocatalysis
Yang Yuan, Qing Zhang, Lin Yang, Liguang Wang, Wenbo Shi, Pengfei Liu, Rui Gao, Lirong Zheng, Zhongwei Chen, Zhengyu Bai
Abstract
Abstract Increasing the portion of highly active metal centers in atomically dispersed MNC catalysts is significant for the overall oxygen reduction reaction (ORR) performance. A “facet strain strategy” is designed by using a trans‐layer compressive strain of the {110} facet of FeCo nanoparticles encapsulated in graphitic FeNC layers to further activate the primitive FeN 4 catalytic centers on the graphitic sub‐layer that are omitted in commonly direct access activation strategies. Using X‐ray absorption near‐edge spectroscopy and extended X‐ray absorption fine structure, the highly active FeN 4 type is detected with compressed FeN bonds. Density functional theory calculation discloses that, in virtue of lattice mismatch, FeCo {110} facets transmit a trans‐layer compressive strain to reconstruct the FeN 4 sites on surrounding graphitic sub‐layers to optimize the Fe‐OH* adsorption energy in the rate‐determining step. The redesigned catalyst exhibits enhanced ORR activity, outperforming the primitive FeNC and commercial Pt/C benchmarks. This study will enrich insights toward developing MN 4 and nanoparticle composite electrocatalysts.