Song Xiaoyun, Ke Shaojie, Ye Qing, Kang Wei, Guan Qingxin, Deng Zhanfeng
Beijing Institute of Smart Energy, Beijing 102209, China.
College of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University, Tianjin 300071, China.
ACS Appl Mater Interfaces. 2024 Oct 2;16(39):52529-52538. doi: 10.1021/acsami.4c12573. Epub 2024 Sep 18.
Proton exchange membrane fuel cells have strict requirements for the CO concentration in H-rich fuel gas. Here, from the perspective of industrial practicability, a highly dispersed Pt catalyst (2-4 nm) supported on activated carbon (AC), which was modified by electronic promoters (K) and structural promoters (isopropanol), is studied in detail. Compared with traditional metal oxide supports, the K-Pt/AC catalysts, which benefit from the tuned charge distribution, achieve a significant reduction of CO (from 1% to <0.1 ppb) under H-rich conditions and show potential for used in large-scale industrial hydrogen purification. Experimental results and theoretical calculations reveal that the K atom, with its lower electronegativity, contributes to the shift of surface Pt to a lower binding energy due to the presence of oxygen species on the AC surface. This facilitates oxygen activation and accelerates desorption of the CO product, thereby accelerating the reaction process and enabling the deep removal of CO in a hydrogen-rich atmosphere.
质子交换膜燃料电池对富氢燃料气中的一氧化碳浓度有严格要求。在此，从工业实用性的角度出发，详细研究了一种负载在活性炭（AC）上的高度分散的铂催化剂（2 - 4纳米），该催化剂通过电子促进剂（K）和结构促进剂（异丙醇）进行了改性。与传统金属氧化物载体相比，得益于电荷分布的调整，K - Pt/AC催化剂在富氢条件下实现了一氧化碳的显著降低（从1%降至<0.1 ppb），并显示出用于大规模工业氢气净化的潜力。实验结果和理论计算表明，由于AC表面存在氧物种，电负性较低的K原子有助于表面铂的结合能向更低值移动。这促进了氧的活化并加速了一氧化碳产物的脱附，从而加速了反应过程，并能够在富氢气氛中深度去除一氧化碳。
