Du Juan, Liu Yicheng, Sun Ming, Guan Jing, Chen Aibing, Han Buxing
College of Chemical and Pharmaceutical Engineering, Hebei University of Science and Technology, 26 Yuxiang Street, Shijiazhuang, 050018, P.R. China.
School of Environmental & Municipal Engineering, Qingdao University of Technology, Qingdao, 266033, P.R. China.
Angew Chem Int Ed Engl. 2025 Jun 10;64(24):e202503385. doi: 10.1002/anie.202503385. Epub 2025 Apr 27.
As a paradigm-shifting material platform in energy catalysis, precisely engineered ordered mesoporous carbon spheres emerge as supreme metal-free electrocatalysts, outperforming conventional carbon-based counterparts through synergistic structural and electronic innovations. Herein, we architecturally design vertically aligned cylindrical mesoporous carbon spheres with atomic-level sulfur doping (S-mC) that establish unprecedented performance benchmarks in the two-electron oxygen reduction reaction (2e-ORR) to hydrogen peroxide. Systematic comparative studies reveal that the S-mC catalysts achieve exceptional HO selectivity (>99%) and activity at current density of -3.5 mA cm, surpassing state-of-the-art metal-free catalysts in current density. Impressively, the optimized S-mC electrocatalyst in a flow cell device achieves an exceptional HO yield of 25 mol g h. The carbon matrix's unique sp/sp hybrid network coupled with S-induced charge redistribution generates electron-deficient hotspots that selectively stabilize *OOH intermediates, as evidenced by in situ spectroscopic characterization and DFT calculations. This structural-electronic synergy endows the carbon framework with metal-like catalytic efficiency while maintaining inherent advantages of chemical robustness and cost-effectiveness. The marriage of S-doping engineering with mesoscopic pore architecture control opens a new way for developing efficient carbon-based electrocatalysts for oxygen selective reduction to HO.
作为能源催化领域中一种范式转变的材料平台，精确设计的有序介孔碳球成为了卓越的无金属电催化剂，通过协同的结构和电子创新超越了传统的碳基同类材料。在此，我们通过原子级硫掺杂构建了垂直排列的圆柱形介孔碳球（S-mC），其在将两电子氧还原反应（2e-ORR）转化为过氧化氢的过程中建立了前所未有的性能基准。系统的对比研究表明，S-mC催化剂在电流密度为-3.5 mA cm时实现了卓越的HO选择性（>99%）和活性，在电流密度方面超过了现有最先进的无金属催化剂。令人印象深刻的是，流动池装置中优化后的S-mC电催化剂实现了25 mol g h的卓越HO产率。碳基质独特的sp/sp杂化网络与S诱导的电荷重新分布产生了缺电子热点，选择性地稳定了*OOH中间体，并通过原位光谱表征和DFT计算得到了证实。这种结构-电子协同作用赋予了碳骨架类似金属的催化效率，同时保持了化学稳定性和成本效益的固有优势。硫掺杂工程与介观孔结构控制的结合为开发用于将氧选择性还原为HO的高效碳基电催化剂开辟了一条新途径。
