Fang Fei, Cheng Qiyang, Wang Mengfan, He Yanzheng, Huan Yunfei, Liu Sisi, Qian Tao, Yan Chenglin, Lu Jianmei
College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215006, China.
College of Energy, Key Laboratory of Core Technology of High Specific Energy Battery and Key Materials for Petroleum and Chemical Industry, Soochow University, Suzhou 215006, China.
ACS Nano. 2025 Jan 14;19(1):1260-1270. doi: 10.1021/acsnano.4c13451. Epub 2025 Jan 3.
Low-temperature direct ammonia fuel cell (DAFC) stands out as a more secure technology than the hydrogen fuel cell system, while there is still a lack of elegant bottom-up synthesis procedures for efficient ammonia oxidation reaction (AOR) electrocatalysts. The widely accepted d-band center, even with consideration of the d-band width, usually fails to describe variations in AOR reactivity in many practical conditions, and a more accurate activity descriptor is necessary for a less empirical synthesis path. Herein, the upper d-band edge, ε, derived from the d-band model, is identified as an effective descriptor for accurately establishing the descriptor-activity relationship. Using the PtCo alloy with varying atomic composition as an example, the ε value succeeds in reflecting the corresponding trends of AOR activity, showing striking linear correlation with a coefficient of determination () as high as 0.90. The effectiveness of the established descriptor-activity relationship is verified experimentally. The optimum electrocatalyst delivers an excellent peak current density of 74.04 A g at 5 mV s, and the assembled DAFC generates a high power density, outperforming the majority of the extensively reported systems. This work brings fundamental insights into the relationship between chemical reactivity and electronic structure and benefits rational optimization of AOR electrocatalyst for next-generation low-temperature DAFC.
低温直接氨燃料电池（DAFC）作为一种比氢燃料电池系统更安全的技术脱颖而出，然而，目前仍缺乏用于高效氨氧化反应（AOR）电催化剂的优雅的自下而上合成方法。即使考虑到d带宽度，广泛接受的d带中心通常也无法描述许多实际条件下AOR反应性的变化，因此需要一个更准确的活性描述符来实现较少经验性的合成路径。在此，从d带模型导出的上d带边缘ε被确定为准确建立描述符-活性关系的有效描述符。以具有不同原子组成的PtCo合金为例，ε值成功反映了AOR活性的相应趋势，显示出高达0.90的决定系数（）的显著线性相关性。通过实验验证了所建立的描述符-活性关系的有效性。最佳电催化剂在5 mV s时提供了74.04 A g的优异峰值电流密度，并且组装的DAFC产生了高功率密度，优于大多数广泛报道的系统。这项工作为化学反应性与电子结构之间的关系带来了基本见解，并有助于下一代低温DAFC的AOR电催化剂的合理优化。
