Atomically Dispersed Iron Regulating Electronic Structure of Iron Atom Clusters for Electrocatalytic H<sub>2</sub>O<sub>2</sub> Production and Biomass Upgrading
Hui Xu, Shengbo Zhang, Xinyuan Zhang, Min Xu, Miaomiao Han, Lirong Zheng, Yunxia Zhang, Guozhong Wang, Haimin Zhang, Huijun Zhao
Abstract
Abstract The integration of highly active single atoms (SAs) and atom clusters (ACs) into an electrocatalyst is critically important for high‐efficiency two‐electron oxygen reduction reaction (2e − ORR) to hydrogen peroxide (H 2 O 2 ). Here we report a tandem impregnation‐pyrolysis‐etching strategy to fabricate the oxygen‐coordinated Fe SAs and ACs anchored on bacterial cellulose‐derived carbon (BCC) (FeSAs/ACs‐BCC). As the electrocatalyst, FeSAs/ACs‐BCC exhibits superior electrocatalytic activity and selectivity toward 2e − ORR, affording an onset potential of 0.78 V (vs. RHE) and a high H 2 O 2 selectivity of 96.5 % in 0.1 M KOH. In a flow cell reactor, the FeSAs/ACs‐BCC also achieves high‐efficiency H 2 O 2 production with a yield rate of 12.51±0.18 mol g cat −1 h −1 and a faradaic efficiency of 89.4 %±1.3 % at 150 mA cm −2 . Additionally, the feasibility of coupling the produced H 2 O 2 and electro‐Fenton process for the valorization of ethylene glycol was explored in detail. The theoretical calculations uncover that the oxygen‐coordinated Fe SAs effectively regulate the electronic structure of Fe ACs which are the 2e − ORR active sites, resulting in the optimal binding strength of *OOH intermediate for high‐efficiency H 2 O 2 production.