【摘要】 Fe-N-C催化剂长期受限于氧还原反应动力学迟缓的问题,这源于其对氧中间体的过度吸附强度及较低的活性位点利用率。杂原子掺杂通过调节金属位点的电子结构优化中间体吸附,有效加速氧还原反应动力学,而化学气相沉积技术可以提升活性位点的周转频率。本文采用双前驱体的化学气相沉积策略,开发出富含FeS₁N₄位点的FeSNC催化剂。实验与理论分析表明,硫元素的引入打破了活性位点的对称配位,将OH^*吸附能从0.212 e V优化至1.194 e V。此外,活性位点的周转频率从1.98 e^–1·site^–1·s^–1提升至6.32 e^–1·site^–1·s^–1,显著增强了催化剂的本征活性。更值得注意的是,含硫物种的亲水性显著提高了掺硫催化剂的亲水性,从而促进了氧气和质子传输。因此,Fe SNC催化剂在0.1 mol·L^–1 HClO₄中表现出极高的0.863 V半波电位,并在H₂-O₂质子交换膜燃料电池中达到1.2 W·cm^–2的峰值功率密度。这项工作突出了配位工程的关键作用。更多还原

【Abstract】 Fe-N-C catalysts have long suffered from kinetically sluggish oxygen reduction reaction（ORR） due to excessive adsorption strength toward oxygen intermediates and low site utilization. Heteroatom doping effectively accelerates ORR reaction kinetics through electronic structure modulation of metal sites for optimal intermediate adsorption, while chemical vapor deposition（CVD） enhances the turnover frequency（TOF） of active sites. Herein, we developed an FeSNC catalyst featuring abundant FeS₁N₄ sites via a dual-precursor CVD strategy. Experimental and theoretical analyses revealed that S incorporation disrupts the symmetric coordination of active sites, which optimizes OH* adsorption energies from 0.212 eV to 1.194 eV. Moreover, the TOF increased from 1.98 e^–1·site^–1·s^–1 to 6.32 e^–1·site^–1·s^–1, significantly enhancing the intrinsic activity of the catalyst. More notably, the hydrophilic character of S-containing species substantially improved hydrophilicity in the S-doped catalyst, thereby promoting mass transport of oxygen and proton delivery. As a result, the FeSNC catalyst exhibited an extremely high half-wave potential of 0.863 V in 0.1 mol·L^–1 HClO₄ and achieved a peak power density of 1.2 W·cm^–2 in H₂-O₂ PEMFCs. This work highlights the critical role of coordination engineering.更多还原