氮掺杂石墨烯气凝胶锚定RuP纳米粒子用于水合肼氧化辅助产氢  

RuP Nanoparticles Anchored on N-doped Graphene Aerogels for Hydrazine Oxidation-Boosted Hydrogen Production

作　　者：王正慜 洪庆玲 王晓慧 黄昊[3] 陈煜[2] 李淑妮[1] Zheng-Min Wang;Qing-Ling Hong;Xiao-Hui Wang;Hao Huang;Yu Chen;Shu-Ni Li(Key Laboratory of Macromolecular Science of Shaanxi Province,School of Chemistry and Chemical Engineering,Shaanxi Normal University,Xi’an 710062,China;School of Materials Science and Engineering,Shaanxi Normal University,Xi’an 710062,China;Department of Microsystems,University of South-Eastern Norway,Borre 3184,Norway.)

机构地区：[1]陕西师范大学化学化工学院,陕西省大分子科学重点实验室,西安710062 [2]陕西师范大学材料科学与工程学院,西安710062 [3]挪威东南大学微系统系,博尔3184,挪威

出　　处：《物理化学学报》2023年第12期103-112,共10页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(21972089,22002083);陕西省创新能力支撑计划(2023-CX-TD-27);中央高校基本科研业务费(GK202202001)资助项目。

摘　　要：氢能是替代传统燃料的理想清洁能源。电解水析氢由于其环保和低成本的特性而受到广泛关注,然而,阳极析氧反应(OER)的缓慢动力学降低了制氢效率。因此,肼氧化反应(HzOR)以其低的理论电压电位(−0.33 V vs.RHE)成为了OER的合理替代方案。本工作中,以三维多孔的石墨烯气凝胶(GA)为导电基底,将Ru^(Ⅲ)-聚乙烯亚胺(Ru^(Ⅲ)-PEI)配合物吸附在GA表面。通过植酸(PA)和PEI之间的氢键相互作用GA进一步吸附PA,形成Ru^(Ⅲ)-PEI-GA-PA复合物。对Ru^(Ⅲ)-PEI-GAPA复合物前驱体进行磷化后,合成了锚定在N掺杂GA上的RuP纳米粒子(RuP/N-GA)。在热解过程中,在GA表面形成了超小的RuP纳米粒子。此外,PEI和PA的分解可以将丰富的N和P杂原子引入GA的结构中。因此,RuP/N-GA复合物具有高效的HzOR性能,在10 mA∙cm^(−2)时的工作电位低至−54 mV。此外,这种低Ru负载的新型RuP/N-GA复合物具有良好的析氢反应(HER)活性,电流密度为10 mA∙cm^(−2)时的HER过电势为−19.6 mV。在各种RuP/N-GA复合物中,RuP/N-GA-900具有最小的HER塔菲尔斜率(37.03 mV∙dec−1),表现出了最快的HER动力学。同时也表明RuP/N-GA-900的HER过程具有与Pt类似的Heyrovsky机制。理论计算结果表明,锚定结构和N杂原子的存在可以促进肼在RuP纳米粒子上的氧化。肼分子吸附在RuP/N-GA上的自由能为−0.68 eV,表明掺杂的N可以调节Ru活性位点的电子结构,有助于增强Ru的HzOR活性。此外,RuP/N-GA复合物对HER和HzOR均表现出优于商业Pt/C的循环稳定性和长期稳定性。基于RuP/N-GA复合物的双功能活性,所构建的双电极肼分解系统在10 mA∙cm^(−2)下表现出41 mV的极低分解电压就可以产氢,实现了低电压下节能制氢的目标。RuP/N-GA复合物优异的电催化活性归因于超小的RuP纳米粒子提供了丰富的Ru活性位点。此外,GA骨架中N的掺杂与RuP纳米颗粒之间的协同效应有助于提高RuP/N-GA复合物的�‘Green hydrogen’is a promising clean energy carrier for use instead of traditional fuels.For obtaining‘green hydrogen’,electrochemical water splitting has been receiving considerable attention due to its ecofriendly and low-cost properties.However,the sluggish kinetics of the anodic oxygen evolution reaction(OER)reduces the efficiency of hydrogen production.Accordingly,the hydrazine oxidation reaction(HzOR)with low theoretical potential(−0.33 V vs.RHE)has been proposed as a reasonable alternative for the OER.In this study,graphene aerogel(GA)was utilized as a conductive substrate with a 3D porous framework.Ru^(Ⅲ)-polyethyleneimine(Ru^(Ⅲ)-PEI)complexes were adsorbed on the GA surface.Phytic acid(PA)was further adsorbed to form Ru^(Ⅲ)-PEI-GA-PA hybrids through the hydrogen bond interaction between PA and PEI,which can serve as a precursor to synthesize RuP nanoparticles anchored on Ndoped GA(RuP/N-GA)through the phosphorization reaction.In the pyrolysis process,the ultra-small RuP was formed at the GA surface.Additionally,the decomposition of PEI and PA can introduce abundant N and P heteroatoms into the structure of GA.As a result,RuP/N-GA hybrids achieve efficient HzOR with a low working potential of−54 mV at 10 mA∙cm^(−2).Moreover,the novel RuP/N-GA hybrids with low Ru loading also exhibit a promising hydrogen evolution reaction(HER)activity with an overpotential of−19.6 mV at 10 mA∙cm^(−2).Among various RuP/N-GA hybrids,the Tafel plot of HER at RuP/N-GA-900 reveals the smallest value to be 37.03 mV∙dec−1,which affords the fastest HER kinetics.Meanwhile,the result suggests that the HER at RuP/N-GA-900 undergoes a Heyrovsky mechanism similar to that of Pt.The theoretical results revealed that the anchored structure and the presence of N heteroatoms can promote the HzOR on RuP nanoparticles.The free energy of hydrazine molecular adsorption on RuP/N-GA was−0.68 eV,indicating that N-doping in the RuP/N-GA structure can adjust the electronic structure of the Ru active site,which also

关 键 词：磷化钌 石墨烯气凝胶 锚定结构 肼氧化反应 析氢反应 

分 类 号：O646.21[理学—物理化学]