Gao Li, Xie Junfeng, Liu Shanshan, Lou Shanshan, Wei Zimeng, Zhu Xiaojiao, Tang Bo
College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes (Ministry of Education), Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Institute of Molecular and Nano Science, Shandong Normal University, Jinan, Shandong 250014, P. R. China.
College of Chemical Engineering and Safety, Binzhou University, Binzhou, Shandong 256603, P. R. China.
ACS Appl Mater Interfaces. 2020 Jun 3;12(22):24701-24709. doi: 10.1021/acsami.0c02124. Epub 2020 May 20.
Hydrazine electro-oxidation has received substantial attention owing to its high energy density, low onset potential, and wide applications in hydrazine-assisted hydrogen production and direct hydrazine fuel cells. In this work, crystalline cobalt/amorphous LaCoO hybrid nanoparticles embedded in porous nitrogen-doped carbon (N-C) were fabricated via pyrolytic decomposition of the dual-metal lanthanum-incorporated zeolitic imidazolate framework (La/ZIF-67), which exhibit high activity and stability toward the electrocatalytic hydrazine oxidation reaction (HzOR). The hybrid nanoparticles based on metallic cobalt and amorphous LaCoO could provide abundant active sites for HzOR catalysis, while the highly conductive and porous N-C could act as both robust skeleton for anchoring the active hybrid nanoparticles and facile charge transport pathway for the HzOR process, thereby resulting in enhanced HzOR activity. With the synergistic merits of enriched active sites, a large surface area, enhanced charge-transfer ability, and intimate catalyst anchoring, promoted HzOR performance with high activity and stability was achieved for the optimized catalyst, which shows an ultralow onset potential of -0.17 V versus reversible hydrogen electrode (RHE), high HzOR current density of 69.2 mA cm at 0.3 V versus RHE, and superior stability for 20 h continuous catalysis, making the catalyst a promising electrode material for hydrazine-assisted hydrogen production.
肼的电氧化因其高能量密度、低起始电位以及在肼辅助制氢和直接肼燃料电池中的广泛应用而受到了广泛关注。在这项工作中，通过热解含镧双金属沸石咪唑酯骨架（La/ZIF-67）制备了嵌入多孔氮掺杂碳（N-C）中的结晶钴/非晶LaCoO混合纳米颗粒，其对电催化肼氧化反应（HzOR）表现出高活性和稳定性。基于金属钴和非晶LaCoO的混合纳米颗粒可为HzOR催化提供丰富的活性位点，而高导电性和多孔性的N-C既可以作为锚定活性混合纳米颗粒的坚固骨架，又可以作为HzOR过程中便捷的电荷传输途径，从而提高HzOR活性。凭借丰富的活性位点、大表面积、增强的电荷转移能力和紧密的催化剂锚定等协同优势，优化后的催化剂实现了具有高活性和稳定性的促进HzOR性能，其相对于可逆氢电极（RHE）的起始电位低至-0.17 V，在0.3 V相对于RHE时HzOR电流密度高达69.2 mA cm，并且具有20小时连续催化的优异稳定性，使该催化剂成为肼辅助制氢的有前景的电极材料。
