The synergism between atomic clusters (ACs)/nanoparticles (NPs) and single atoms has recently become a research focus. However, previous works often focus on the simple interaction between pure NPs and SAs ( partial view ), instead of attention on how can we modify NPs or ACs to strengthen the intrinsic activity of whole metal NPs/ACs@M-N-C entity ( integral perspective ). Therefore, the strategies over the precise construction and performance optimization of entire metal NPs/ACs@M-N-C entity remained to be investigated.
In this study, Co-Cu alloy NPs@Co-N-C (CC@CNC) was constructed using Co/Cu-modified zeolitic imidazolate framework-8 (ZIF-8) as precursor, followed by the pyrolysis and acid etching. The incorporation of Cu induced formation of Co-Cu alloy NPs, originating from the low Tammann temperature of Cu, which was verified by the negative cohesive energy of Co 10 Cu 3 (−0.06454, intending to aggregation) compared to that of Co 13 (+1.690995, intending to dispersion). The Co-Cu alloy NPs-supported Co SAs showed superior PMS activation efficiency compared to Co NPs-supported Co SAs (Co NPs@Co-N-C, C@CNC), evidenced by the decreased energy barriers of PMS adsorption (increased Co–O bond length)/PMS oxidation (increased O-H bond length and decreased O-O bond length) and SO 5 ·- desorption (increased Co-O bond length), through optimizing dz 2 -O (PMS) and dxz -O (SO 5 ·- ) interaction. Therefore, the CC@CNC highly efficiently removed 80.67% of 20 mg/L carbamazepine (CBZ) within 5 min, which was superior to the C@CNC counterpart (58.99% within 5 min). The serial quasi in situ techniques indicated the occurred PMS oxidation reaction on Co SAs, which can selectively generate 1 O 2 to effectively eliminate CBZ. This study can lay solid foundation for the performance optimization strategy and underlying mechanism revelation in metal multiple-atom assembly@metal SAs catalysts at atomic orbital level.
Science Bulletin