Atomic Confinement Empowered CoZn Dual‐Single‐Atom Nanotubes for H <sub>2</sub> O <sub>2</sub> Production in Sequential Dual‐Cathode Electro‐Fenton Process
Lijun Yang, Huimin Cheng, Hui Li, Ga Sun, Sitong Liu, Tianyi Ma, Lei Zhang
Abstract
Abstract Single‐atom catalysts (SACs) are flourishing in various fields because of their 100% atomic utilization. However, their uncontrollable selectivity, poor stability and vulnerable inactivation remain critical challenges. According to theoretical predictions and experiments, a heteronuclear CoZn dual‐single‐atom confined in N/O‐doped hollow carbon nanotube reactors (CoZn SA @CNTs) is synthesized via spatial confinement growth. CoZn SA @CNTs exhibit superior performance for H 2 O 2 electrosynthesis over the entire pH range due to dual‐confinement of atomic sites and O 2 molecule. CoZn SA @CNTs is favorable for H 2 O 2 production mainly because the synergy of adjacent atomic sites, defect‐rich feature and nanotube reactor promoted O 2 enrichment and enhanced H 2 O 2 reactivity/selectivity. The H 2 O 2 selectivity reaches ∼100% in a range of 0.2–0.65 V versus RHE and the yield achieves 7.50 M g cat −1 with CoZn SA @CNTs/carbon fiber felt, exceeding most of the reported SACs in H‐type cells. The obtained H 2 O 2 is converted directly to sodium percarbonate and sodium perborate in a safe way for H 2 O 2 storage/transportation. The sequential dual‐cathode electron‐Fenton process promotes the formation of reactive oxygen species (•OH, 1 O 2 and •O 2 − ) by activating the generated H 2 O 2 , enabling accelerated degradation of various pollutants and Cr(VI) detoxification in actual wastewater. This work proposes a promising confinement strategy for catalyst design and selectivity regulation of complex reactions.