设计廉价高效的过渡金属/氮共掺杂碳材料并作为铂基材料的替代物应用于电催化氧还原反应(ORR),是目前加速燃料电池技术大规模商业化的有效途径之一,也是当前研究的焦点和难点. 本文通过表面活性剂的辅助在氧化石墨烯(GO)表面原位生长钴掺杂的ZIF-8 (Co-ZIF-8),以此为前驱体经过一步碳化得到二维5% Co/N-GO碳纳米材料,实现了钴/氮活性位点和介孔结构的同步构筑. 5% Co/N-GO在碱性条件下具有非常优异的ORR催化性能,其起始电位、半波电位、极限电流密度和稳定性都优于商业Pt/C,同时表现出极优的四电子选择性. 这些优异的性能主要得益于二维超薄的介孔结构大大促进了反应过程的物料传输和活性位点的暴露率;同时,高度分散的CoNx活性位点与氮掺杂位点产生高效的协同催化作用,显著增强了该材料的电催化氧还原性能.%Designing a low-cost and efficient transition metalitrogen co-doped carbon materials as the alternative of platinum-based materials applied to electrocatalytic oxygen reduction reaction is one of the effective methods to accelerate the large-scale commercialization of fuel cell technology. In this paper, co-balt doped ZIF-8 (Co-ZIF-8) was in-situ grown on the surface of graphene oxide (GO) with the assist of surfactant, and then was carbonized in one step to get two-dimensional carbon nanomaterials 5%Co/N-GO. The 5%Co/N-GO realized simultaneous building of Co/N active sites and the mesoporous structure. The 5% Co/N-GO showed excellent ORR catalytic performance under alkaline condition, its onset potential,half potential, ultimate current density and stability were all superior to commercial Pt/C, and showed extremely excellent four electron selectivity.This excellent performance mainly profited from that the two-dimensional ultrathin mesoporous structure greatly facilitated the material transfer and the exposure rate of the active sites.Simultaneously, the synergistic catalysis between the highly dispersed CoNxactive sites and nitrogen doping sites significantly enhance the catalytic performance of 5%Co/N-GO.
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