Dichao Shi , Wen Fang , Afang Zhang , Wenhua Bao , Li Zhang , Sébastien Paul
{"title":"Selective hydrodeoxygenation of furfural to 2-methylfuran over Ni-Co/SiO2 bimetallic catalysts: Synergistic effect of metal and acid sites","authors":"Dichao Shi , Wen Fang , Afang Zhang , Wenhua Bao , Li Zhang , Sébastien Paul","doi":"10.1016/j.jece.2025.116252","DOIUrl":"10.1016/j.jece.2025.116252","url":null,"abstract":"<div><div>The development of Ni-based bimetallic catalysts with optimized surface composition and optimized structural properties is crucial for the selective hydrodeoxygenation (HDO) of furfural (FF) into 2-methylfuran (2-MF) which can be used as a fuel additive. In this study, a series of Ni-Co nanoparticles with various Ni/Co molar ratios, supported on SiO<sub>2</sub> were synthesized <em>via</em> the deposition-precipitation method and applied to this HDO reaction. The Ni-Co nanoparticles were uniformly dispersed on silica and displayed a core-shell structure with a gradient of Ni concentration, transitioning from a Ni-enriched core to a Co-enriched outer shell. Optimizing the Ni/Co ratio in these nanoparticles and leveraging the acidic sites generated by CoO<sub><em>x</em></sub> species led to complete FF conversion and a 2-MF yield of up to 90 % at 170 °C, 2 MPa, after 180 min of reaction. The surface composition in Ni and Co was correlated to the catalytic performance. It was found that Co addition not only altered FF adsorption on nanoparticles from a parallel to a tilted configuration, but also transferred electrons from Co to Ni, resulting in electron-rich Ni<sup>0</sup> sites. This electron transfers enhanced H<sub>2</sub> dissociation into H<sup>+</sup> and H<sup>-</sup>, which then migrated to oxygen vacancies (O<sub>V</sub>) near Co<sup>δ+</sup> species, effectively hydrogenating the C<img>O bond adsorbed on Co<sup>δ+</sup> species and promoting the high production of 2-MF. Kinetic studies revealed that the HDO of FF follows a first-order reaction. The Ni-Co/SiO<sub>2</sub> catalyst also demonstrated excellent reusability, maintaining high activity over three cycles.</div></div>","PeriodicalId":15759,"journal":{"name":"Journal of Environmental Chemical Engineering","volume":"13 3","pages":"Article 116252"},"PeriodicalIF":7.4,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sustainable acid dye removal: A biocatalytic approach using glyoxal-immobilized oxidase enzymes","authors":"Anh T.P. Hoang, Kyoung-Woong Kim","doi":"10.1016/j.jece.2025.116236","DOIUrl":"10.1016/j.jece.2025.116236","url":null,"abstract":"<div><div>Immobilized oxidase enzymes have been widely investigated for their potential to degrade dyes, and offer a promising approach for textile wastewater treatment. However, in many immobilization methods, a major obstacle in applying immobilized enzymes to wastewater treatment is the reliance on potentially toxic chemicals, in particular, crosslinking agents for covalent immobilization, which can introduce secondary risks to the aquatic ecosystem. This study evaluates the use of glyoxal, a less toxic alternative, as a crosslinking agent for immobilizing horseradish peroxidase (HRP) and laccase onto chitosan beads. The immobilized enzymes were tested for the removal of Acid Green 25 (AG 25) and Acid Red 1 (AR 1) dyes under various pH levels, temperatures, and contact times. At 30 °C and pH 6.5, the immobilized enzymes removed (80 −84) % of Acid Green 25 dye and 71 % of Acid Red 1 dye after 4 h. Characterization of the immobilized enzymes confirmed successful crosslinking and structural stability, while metabolite analysis suggested potential dye degradation pathways. By utilizing glyoxal at a lower concentration (0.4 %) compared to traditional glutaraldehyde methods (typically 0.8 %), this approach reduces chemical input and ecotoxicity while maintaining high dye removal efficiency. These findings highlight the potential of glyoxal-crosslinked immobilized enzymes on chitosan beads as a sustainable and effective solution for textile wastewater treatment.</div></div>","PeriodicalId":15759,"journal":{"name":"Journal of Environmental Chemical Engineering","volume":"13 3","pages":"Article 116236"},"PeriodicalIF":7.4,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hao Su , Bingyan Dong , Jiaxin Luo , Cunwen Fan , Longwen Xiao , Dachao Zhang
{"title":"Long-term cumulative toxicity of low-dose lanthanum on nitrifying bacteria in partial nitrification process: Mechanism of disruption of intracellular calcium homeostasis","authors":"Hao Su , Bingyan Dong , Jiaxin Luo , Cunwen Fan , Longwen Xiao , Dachao Zhang","doi":"10.1016/j.jece.2025.116225","DOIUrl":"10.1016/j.jece.2025.116225","url":null,"abstract":"<div><div>Due to differences in ion uptake, aerobic bacteria are more prone to metal accumulation toxicity than anaerobic bacteria, while the potential long-term environmental risks of lanthanum (La(III)) on aerobic ammonia oxidizing bacteria are unknown. In this study, the effects and mechanisms of long-term (Within 99 days) exposure to low-dose (0.5–5.0 mg/L) La(III) on partial nitrification (PN) process were illuminated. Firstly, after long-term exposure to La(III), the performance of PN process was decreased by 8–48 % as both <em>Nitrospira</em> and <em>Nitrosomonas</em> are enriched simultaneously when La(III) of 0.5–2.5 mg/L, and collapsed with a sharp decrease in <em>Nitrospira</em> and <em>Nitrosomonas</em> when La(III) of 5.0 mg/L. Secondly, when La(III) reaches 5 mg/L, electrostatic interactions and hydrogen bonds are enhanced through the formation of La(III)- alginate network structure, which promotes the synthesis of lanthanum nanoparticles. Finally, the formed lanthanum nanoparticles bind to calcium ion (Ca(II)) channels on the cell membrane, which disrupted intracellular calcium homeostasis and resulted in oxidative damage to functional bacteria. This study fills the knowledge gap in the long-term effects and mechanisms of low-dose lanthanum on autotrophic nitrifying bacteria.</div></div>","PeriodicalId":15759,"journal":{"name":"Journal of Environmental Chemical Engineering","volume":"13 3","pages":"Article 116225"},"PeriodicalIF":7.4,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Humidity-resistant air filtration and passive respiratory sensing by direct metal–organic framework functionalization and nanopore generation at electroactive poly(lactic acid) nanofibers","authors":"Xinjian He , Yuyang Chen , Ruizi Chen , Yifan Zhang , Shihang Li , Jiang Shao , Xiaoyu Chen , Mingming Zhang , Shenghui Zhang , Long Zhang , Jiefeng Gao , Huan Xu","doi":"10.1016/j.jece.2025.116214","DOIUrl":"10.1016/j.jece.2025.116214","url":null,"abstract":"<div><div>The development of ecofriendly poly(lactic acid) (PLA) nanofibrous membranes (NFMs) is of important significance to settle down the rapidly rising airborne PM crisis and plastic pollutions, but suffering from the bottlenecks in terms of the relatively low surface activity, poor electret properties and fiber refinement. This work unraveled an effective approach for MOF functionalization and nanopore creation at PLA nanofibers by the modified electrospinning–electrospray technique, combined with electro-induced stereocomplexation (EIS) principles to enhance surface activity, electroactivity, and electret properties of PLA NFMs. The proposed PLA NFMs presented superior PM<sub>0.3</sub> capturing efficiency (95.91 % at 30 % RH, 88.01 % at 90 % RH), humidity resistance and breathability (40.3 Pa at 32 L/min). Benefiting from the triboelectric nanogenerator mechanisms, the PLA NFMs enabled long-term efficient filtration and permitted multifunctional applications like passive respiratory monitoring and voice recognition, appealing for human-machine interactions while providing efficient healthcare.</div></div>","PeriodicalId":15759,"journal":{"name":"Journal of Environmental Chemical Engineering","volume":"13 3","pages":"Article 116214"},"PeriodicalIF":7.4,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qian Zhang , Chen-Zhi Wu , Zhi Huang , Yan-ying Liu , Jun-ming Hong
{"title":"Electrochemical treatment of bisphenol a facilitated by a dual-ligand copper metal-organic framework/graphene oxide hybrid catalyst","authors":"Qian Zhang , Chen-Zhi Wu , Zhi Huang , Yan-ying Liu , Jun-ming Hong","doi":"10.1016/j.jece.2025.116243","DOIUrl":"10.1016/j.jece.2025.116243","url":null,"abstract":"<div><div>Electrochemical degradation via metal-organic framework/graphene oxide catalyst (MOF/G) is an emerging hot topic for pollutants removing under marine wastewater conditions. In this research, dual-ligand MOF/G with Cu center (Cu-IH/G) were prepared to trigger electrocatalysis. As characterization results, and synergetic effect of dual ligand was conducive to adjusting the electronic distribution of Cu-IH/G and enhancing its electrocatalytic performance. The use of Cu-IH/GO enables the rapid removal of bisphenol A (BPA) at 100 % efficiency in less than 10 min. The dual-ligand catalyst demonstrated superior degradation rates compared to electrocatalysts utilizing a single ligand (Cu-I/G and Cu-I/G). Besides, Cu-IH/G maintained stable efficiency under various conditions of pH, temperature, current and even co-existence of complex microflora. According to radical quantitative detection and electron paramagnetic resonance (EPR), singlet oxygen, O<sup>2-</sup>, and active chlorine as primary active substances involved in the reaction was successfully identified. Subsequently, plausible pathways for the degradation of BPA were proposed. This research developed an effective strategy for electrocatalysts design to achieve high salt-resistance and pH-resistance MOF/G materials.</div></div>","PeriodicalId":15759,"journal":{"name":"Journal of Environmental Chemical Engineering","volume":"13 3","pages":"Article 116243"},"PeriodicalIF":7.4,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jingke Song , Xin Zhao , Ruirui Liu , Songsong Zhi , Ruixue Han , Jiangzhou Xie , Jianhui Sun , Kai Jiang , Dapeng Wu
{"title":"Layered double hydroxides-engineered biochar for selective phosphate recovery by flow-electrode capacitive deionization","authors":"Jingke Song , Xin Zhao , Ruirui Liu , Songsong Zhi , Ruixue Han , Jiangzhou Xie , Jianhui Sun , Kai Jiang , Dapeng Wu","doi":"10.1016/j.jece.2025.116245","DOIUrl":"10.1016/j.jece.2025.116245","url":null,"abstract":"<div><div>Flow-electrode capacitive deionization (FCDI) shows great potential for efficient phosphorus (P) extraction from wastewater. In this study, we introduce Mg-Al layered double hydroxides-engineered biochar (Mg-Al LDHs/BC) as flow electrodes in FCDI systems, demonstrating enhanced selective P removal and recovery. A higher Mg/Al ratio (4:1) increased the interlayer spacing of Mg-Al LDHs, enhanced the specific surface area, and improved the P static adsorption capacity (132.32 mg P g<sup>−1</sup>) of the electrode materials. Under various operating conditions, FCDI with Mg-Al LDHs/BC as flow electrodes exhibited superior selectivity for phosphate ions compared to BC flow electrodes. In a 20-hour continuous treatment of artificial wastewaters, FCDI removed 52.3 % of the P in the influent, with 96.6 % adsorbed onto Mg-Al LDHs/BC electrodes while maintaining a low energy consumption (15.4–18.5 kWh kg<sup>−1</sup> P). This shows that the energy consumption, P removal efficiency and selectivity in our system are comparable to those reported in earlier studies. The strong affinity of Mg-Al LDHs/BC for HPO<sub>4</sub><sup>2-</sup> enhanced selective adsorption of P in FCDI, driven by electrostatic adsorption and ligand exchange mechanisms. Our study demonstrates that Mg-Al LDHs/BC, with its high selectivity for P, enhances the selective removal of P in the FCDI system and is effectively immobilized on the electrode material for P recovery.</div></div>","PeriodicalId":15759,"journal":{"name":"Journal of Environmental Chemical Engineering","volume":"13 3","pages":"Article 116245"},"PeriodicalIF":7.4,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shaobin Mei, Pengpeng He , Jinhe Li, Lijuan Sun , Wei Ren, Chunxia Wu, Weikang Wang , Qinqin Liu
{"title":"ZnIn2S4 synergized with BiVO4 to construct S-scheme heterojunction photocatalysts for highly efficient production of oxygen and benzaldehyde","authors":"Shaobin Mei, Pengpeng He , Jinhe Li, Lijuan Sun , Wei Ren, Chunxia Wu, Weikang Wang , Qinqin Liu","doi":"10.1016/j.jece.2025.116191","DOIUrl":"10.1016/j.jece.2025.116191","url":null,"abstract":"<div><div>BiVO<sub>4</sub> is a typical oxidative semiconductor, characterized by strong oxidation capability, visible-light response and high activity. Nevertheless, its application is hindered by the rapid recombination of photogenerated carriers, and insufficient reduction capability. To address this issue, ZnIn<sub>2</sub>S<sub>4</sub>, an efficient reducing semiconductor, was coupled with BiVO<sub>4</sub> to form an S-scheme heterojunction (BVZS) enriched with surface oxygen vacancies. Driven by the S-scheme charge transfer mechanism, the BVZS possesses improved visible-light harvesting, robust redox capability and rapid separation of photogenerated carriers, enabling bi-functional applications in O<sub>2</sub> generation from water splitting, and aerobic benzyl alcohol conversion to produce benzaldehyde (BAD). Under Xenon lamp, the O<sub>2</sub> evolution and BAD yield of the ZnIn<sub>2</sub>S<sub>4</sub>/BiVO<sub>4</sub> reached 2208.49 µmol g<sup>−1</sup> h<sup>−1</sup> and 7.40 mmol g<sup>−1</sup> h<sup>−1</sup>, outperforming most of reported ZnIn<sub>2</sub>S<sub>4</sub> or BiVO<sub>4</sub>-based systems. This work presents a promising strategy for designing bi-functional heterojunction catalysts to achieve water splitting and organic synthesis.</div></div>","PeriodicalId":15759,"journal":{"name":"Journal of Environmental Chemical Engineering","volume":"13 3","pages":"Article 116191"},"PeriodicalIF":7.4,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Enhancing SO2 emission concentration prediction in ammonia flue gas desulfurization systems through continual learning","authors":"Baochang Xu , Peng Chen","doi":"10.1016/j.jece.2025.116248","DOIUrl":"10.1016/j.jece.2025.116248","url":null,"abstract":"<div><div>Accurately predicting SO<sub>2</sub> concentration at the outlet of ammonia flue gas desulfurization (FGD) systems is crucial for optimizing process parameters in power plants, thereby improving desulfurization efficiency and reducing SO<sub>2</sub> emissions. However, modeling the mechanism of the ammonia FGD system is challenging due to the large number of interacting components. Additionally, existing data-driven deep learning models often struggle with long-term online predictions as the forecasting horizon extends and new data is introduced. To address these challenges, we propose a novel continual learning approach, termed Experience and Model Parameters Replay (EMPR). By integrating EMPR with the iTransformer model, an online prediction model called iTransformer-EMPR is developed to predict SO<sub>2</sub> emission dynamics in ammonia FGD systems. This model utilizes variate tokens to capture correlations among multiple feature variables within the desulfurization system and applies the EMPR algorithm for dynamic model updates. Using actual data from the combustion boiler at the Karamay Petrochemical Co. thermal power plant in Xinjiang, a case study demonstrates the model’s effectiveness in predicting SO₂ emissions 10 minutes in advance. The experiment results show that the iTransformer-EMPR model significantly outperforms existing approaches, reducing RMSE (Root Mean Square Error) by 69.0 %, 63.1 %, and 10.2 % compared to LSTM, Informer, and iTransformer models, respectively. Furthermore, compared to continual learning algorithms MAS and DER+ +, RMSE reductions of 7.8 % and 5.9 % are achieved. Additionally, the EMPR algorithm demonstrates strong generalization capability, reducing RMSE by 6.8 % and 8.4 % when applied to LSTM and Informer models, respectively.</div></div>","PeriodicalId":15759,"journal":{"name":"Journal of Environmental Chemical Engineering","volume":"13 3","pages":"Article 116248"},"PeriodicalIF":7.4,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nwaokoma Chigozie Junior , Yuxuan Du , Yating Wang , Guisheng Zhao , Jiuyu Li , Aqsa Riaz , Jianping Du
{"title":"Self-assembled aggregates of SnO2/Bi2O3 heterojunction for electrochemical H2O2 detection","authors":"Nwaokoma Chigozie Junior , Yuxuan Du , Yating Wang , Guisheng Zhao , Jiuyu Li , Aqsa Riaz , Jianping Du","doi":"10.1016/j.jece.2025.116260","DOIUrl":"10.1016/j.jece.2025.116260","url":null,"abstract":"<div><div>A novel electrochemical sensor was created for the rapid and effective detection of hydrogen peroxide, employing a SnO<sub>2</sub>/Bi<sub>2</sub>O<sub>3</sub>-modified electrode. SnO<sub>2</sub>/Bi<sub>2</sub>O<sub>3</sub> with heterostructure was prepared using a simple hydrothermal approach, followed by the comprehensive characterization of structure, morphology and properties. Optimal SnO<sub>2</sub>/Bi<sub>2</sub>O<sub>3</sub> material exposed (101) crystal planes of SnO<sub>2</sub> and (-122) crystal planes of Bi<sub>2</sub>O<sub>3</sub>. The sensor's performance for detecting hydrogen peroxide was evaluated, revealing a significant sensing capability, with a high sensitivity of 318.45 μA mM<sup>−1</sup>cm<sup>−2</sup> and a low detection limit (LOD) of 0.29 μM, and as-prepared SnO<sub>2</sub>/Bi<sub>2</sub>O<sub>3</sub> is far superior to some reported materials. Additionally, the sensor's response to H<sub>2</sub>O<sub>2</sub> was examined in the presence of different potential interfering species. The findings confirm that the designed sensor exhibits high selectivity, reproducibility and stability for the detection of H<sub>2</sub>O<sub>2</sub>, and notably SnO<sub>2</sub>/Bi<sub>2</sub>O<sub>3</sub> was used to construct chip paper electrodes, and achieve portable and highly-sensitive detection of H<sub>2</sub>O<sub>2</sub>. These findings highlight the potential of the as-synthesized SnO<sub>2</sub>/Bi<sub>2</sub>O<sub>3</sub> as a promising material for hydrogen peroxide detection in the environment and health fields.</div></div>","PeriodicalId":15759,"journal":{"name":"Journal of Environmental Chemical Engineering","volume":"13 3","pages":"Article 116260"},"PeriodicalIF":7.4,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yingxuan Wu , Tong Wang , Dongnian Zhang , Mengmeng Wang , Wenhan Yang , Chuncai Kong , Zhimao Yang , Shengchun Yang , Hao Zhu
{"title":"High-spin atomically dispersed Mn(II)N4 site: Unraveling the catalytic activity and selectivity of oxygen reduction reaction in microbial fuel cell","authors":"Yingxuan Wu , Tong Wang , Dongnian Zhang , Mengmeng Wang , Wenhan Yang , Chuncai Kong , Zhimao Yang , Shengchun Yang , Hao Zhu","doi":"10.1016/j.jece.2025.116232","DOIUrl":"10.1016/j.jece.2025.116232","url":null,"abstract":"<div><div>Microbial fuel cell (MFC) presents an innovative eco-friendly technology, but its development is greatly hindered by expensive and inefficient cathodic oxygen reduction reaction (ORR) catalysts. Currently, CN-coordinated single-atom Fe-based or Co-based materials report have been widely recognized as a promising ORR catalyst. However, this application is constrained by the Fenton reaction. Consequently, it is particularly necessary to further advance innovative non-precious metal ORR catalysts. Herein, atomically dispersed Mn-N-C catalysts with a precise Mn(II)N<sub>4</sub> structure are developed using a one-step calcination method, which is served as MFC cathodes for the ORR. The optimized Mn-N-C catalyst demonstrates a half-wave potential (E<sub>1/2</sub>) of 0.864 V, surpassing that of commercial Pt/C (0.855 V). Specifically, the catalyst exhibits outstanding four-electron ORR selectivity with H<sub>2</sub>O<sub>2</sub> yields below 4 %. Theoretical calculations indicate that the generation of H<sub>2</sub>O<sub>2</sub> by *OOH protonation at the Mn(II)N<sub>4</sub> site is a non-spontaneous process. The high-spin Mn(II)N<sub>4</sub> site greatly enhances catalytic activity through increased electron delocalization and effective interaction between σ and π orbitals near the Fermi energy level. Accordingly, Mn-N-C present excellent power density and high chemical oxygen demand (COD) removal in MFC. This study provides new insight about the metal valence state at the center of Mn single-atom materials in relation to ORR activity and selectivity.</div></div>","PeriodicalId":15759,"journal":{"name":"Journal of Environmental Chemical Engineering","volume":"13 3","pages":"Article 116232"},"PeriodicalIF":7.4,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}