第一作者:Dongchen Yang
通讯作者:张金林 教授
通讯单位:河北农业大学植物保护学院
通讯作者:高书涛 教授
通讯单位:河北农业大学理学院
DOI:10.1016/j.apcatb.2024.124768
开发稳定高效的钴基催化剂用于降解水中的新污染物(ECs)被认为是避免高级氧化工艺(AOPs)中二次污染的实用策略。在此,我们采用 2,2'-联吡啶辅助热解方法开发了一种超稳定钴基链帆催化剂(Co-NC900)。在 Co-NC900 和过一硫酸盐(PMS)的作用下,水中超过 96.6% 的吡虫啉(IMD)可在 5 分钟内降解。令人惊讶的是,Co-NC900 在运行 15 次之后,对 IMD 的降解效率仍高达 95%。密度泛函理论(DFT)计算表明,Co-NC900 可通过独特的乒乓机制(C-N 键断裂和再形成过程)有效激活 PMS,并进一步降解 ECs。这项研究为开发高效、稳定的金属催化剂去除水中的氨基甲酸乙酯提供了一种新方法。
Scheme 1. Illustration of the catalytic degradation mechanism of Co-NC900.
Fig. 1. Synthetic strategy and characterizations. a) A schematic illustration of the preparation strategy. b,c) HRTEM images of Co-NC900. d) XRD of Co-NC900F and Co-NC900. e) XPS survey spectra of Co, O, N, and C in Co-NCx (x represents the pyrolysis temperature). f) High-resolution Co 2p XPS spectra of Co-NC900 obtained after etching depth of about 10 nm. g) High-resolution N1s XPS spectra of Co-NCx. h) Raman spectra of Co-NCx. i) N2 adsorption-desorption isotherms of Co-NC900. inset: The corresponding pore size distribution.
Fig. 2. a) Normalized Co K-edge XANES spectra of Co-NC900 with standard references. b) FT-EXAFS spectra of Co-NC900 in R-space with standard references. c-f) The wavelet transform of Co-NC900 (c) and the references of Co-foil (d), CoO (e), and Co3O4 (f).
Fig. 3. Catalytic performance of Co-NC900/PMS process. a) IMD degradation performance in different reaction systems. b-d) Effect of IMD concentration, aqueous matrix, and ions (5 min) on IMD degradation by Co-NC900-activated PMS. e) The schematic illustration of the continuous flow system. f) Continuous operation test of IMD degradation in the continuous flow system. g) IMD degradation in 15 consecutive cycles in the Co-NC900/PMS system. h) Degradation of multiple pollutants in the Co-NC900/PMS system after 5 min reactions. Reaction conditions: [catalyst] = 0.05 g L−1, [PMS] = 0.5 mM, [pollutants] = 2.5 mg L−1 (The concentration of glyphosate in Fig. 2h is 100 mg L−1), [Temp.] =25 ± 2 °C.
Fig. 4. a) ESR spectra of ROS detected in the Co-NC900/PMS system. Reaction condition: [Co-NC900] = 0.05 g L−1, [PMS] = 0.5 mM, [Temp.] =25 °C, [Time] = 2 min−1. b) The ratio of SO4•−, HO•, and 1O2 exposure to PMS exposure. c) Concentrations of PMS and ROS in the Co-NC900/PMS system. d) Comparison of experimentally measured and model-predicted of IMD degradation rates in the Co-NC900 system. e) In the Co-NC900/PMS system, the fractional contribution of SO4•− (f SO4•−), HO• (f HO•), 1O2 (f 1O2), PMS (f PMS), and adsorption (f ads) to the degradation process of selected compounds. Reaction conditions for (b-e): [catalyst] = 0.005 g L−1, [PMS] = 0.5 mM, [pollutants] = 0.2 mg L−1, [Temp.] =25 ± 2 °C.
Fig. 5. (a) Modeling of Co-NC900. (b) Charge density difference analysis of Co-NC900, Yellow and blue colors represent electron accumulation and reduction regions, respectively, with an isosurface value of 0.0025 e Å−3. (c-d) Comparison of LDOS of total carbon 2p orbitals of HC and CoC (c), HC-GrN and CoC-GrN (d), and comparison of PDOS of adsorption site C2p orbitals and N2p orbitals. The Fermi level is set as zero. (e) Comparison of adsorption energies of different models for OI and OII sites of PMS. (f) PMS bader charge increase for different adsorption models. (g-h) Charge density difference of the OI site and the OII site on PMS adsorbed by CoC-GrN model. (Isosurface value of 0.0025 e Å−3). (i) Gibbs free energy change of two pathways for SO4•− and HO• production by Co-C-GrN catalyzed PMS.
总之,我们通过热解成功合成了一种结构高度稳定的钴基链邮催化剂(Co-NC900)。内核中的钴原子和外壳层中的碳原子之间的电子传递有效地活化了 PMS,产生了多种活性氧(如 SO4--、HO--、1O2 和 O2--),能在 5 分钟内降解 96.6% 的 IMD。具体来说,SO4--和 HO--对 IMD 的降解具有重要作用。Co-NC900 具有掺氮碳壳层的保护作用,表现出很高的稳定性,这体现在它在连续使用 15 次和 7 天后,IMD 降解活性仍保持在 95% 以上,同时钴离子浸出极少(0.083 μg L-1)。Co-NC900/PMS 工艺对 32 种常见 EC 具有广泛的适用性和卓越的降解效率。同时,Co-NC900/PMS 工艺可显著降低 IMD 的环境风险。总之,Co-NC900 在未来水环境中农药和其他易溶于水物质的管理方面具有潜在的应用前景。
Dongchen Yang, Zexiu An, Jingqian Huo, Lai Chen, Haijiao Dong, Weidi Duan, Yaxin Zheng, Minghua Wang, Maoxia He, Shutao Gao, Jinlin Zhang, Ultrastable cobalt-based chainmail catalyst for degradation of emerging contaminants in water, Applied Catalysis B: Environment and Energy, 2025, https://doi.org/10.1016/j.apcatb.2024.124768
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