【作者】 李丹；

【导师】 徐轶；

【作者基本信息】 西南交通大学 ， 材料科学与工程， 2021， 硕士

【摘要】 随着未来社会对新能源的需求日益增加,清洁高燃烧值的氢能源成为大家关注的重点。现有制氢方式主要存在污染环境和产物纯度较低的问题,这就需要采用环保高效的电解水制氢技术。但是,催化剂的高成本和稀缺性是电解水制氢目前面临的关键问题。因此,开发和制备一种储量丰富、成本低廉的非贵金属催化剂,以取代贵金属催化剂用于电解水析氢反应（HER）具有重要的研究意义。过渡金属磷化物（TMP）在缓解能源危机的催化应用方面具有很大的潜力。研究表明,基于多孔材料的催化剂具有比表面积大、活性高的优点,而材料元素组成形成的协同效应也有利于增强电子传输从而加快析氢效率。基于此,本研究主要制备了Ni-P/CNTs和Mn-NiP两种电催化剂材料,其主要研究内容如下:（1）采用气雾化和碱溶液浸出法从镍铝合金（Ni-Al）中制备了多孔骨架镍粉,并探讨了浸出反应温度、时间以及不同粒径下制备的粉末的孔结构差异性,得出该方法制备的骨架镍粉具有一定的催化活性,可作为催化剂的有效前驱体材料。（2）采用多孔镍粉作为基体并负载碳纳米管,利用简单、有效的高温磷化方法在多孔镍粉表面生长了一种磷化镍阵列片（Ni-P/CNTs）催化剂材料。在酸性条件下,700℃下磷化60分钟制备的Ni-P/CNTs催化剂比该实验其他工艺条件下制备的催化剂具有更好的催化活性,这可能与催化剂的阵列片状形貌、电化学活性表面积和P含量有关。此外,该条件下制备的催化剂还表现出优异的析氢稳定性。这项工作将为设计各种过渡金属化合物以及探索多孔金属材料在能源相关催化过程中的催化剂性能提供一条有前景的途径。（3）采用上述方法,将第二种金属锰粉掺杂到多孔镍粉与红磷粉末中,经过高温磷化,构建了一种具有双金属成分的多相磷化镍(Ni₃P、Ni₂P、Ni₁₂P₅)催化剂材料（Mn-NiP）。得益于掺杂的Mn对Ni的电子结构的调控作用以及Ni与P的相互电子作用,适量Mn掺杂的催化剂的析氢活性有所增加。主要探究了3Mn-NiP在全p H范围的析氢活性,结果表明,3Mn-NiP在0.5 M H₂SO₄和1.0 M KOH中产生10 m A?cm^-2电流密度所需的过电位值分别为164和77 m V,在碱性环境中表现出更加优异的HER活性,同时,3Mn-NiP在碱性环境中具有优异的电化学耐久性,在持续24小时测试后也未出现明显的活性减弱。更多还原

【Abstract】 With the increasing demand for new energy in the future,clean hydrogen energy with high combustion valued has become the focus of attention.The existing hydrogen production methods mainly suffer from environmental pollution and low product purity,which requires the use of environmentally friendly and efficient hydrogen production technology by electrolysis of water.However,the high cost and scarcity of catalysts are the key problems in the electrolysis of water for hydrogen production.Therefore,it is of great significance to develop and prepare an abundant and low-cost non-noble metal catalyst to replace noble metal catalyst for the hydrogen evolution reaction（HER）.Transition metal phosphides（TMPs）have great potential in catalytic applications to alleviate the energy crisis.The studies have shown that catalysts based on porous materials have the advantages of the large specific surface area and good activity.The synergistic effect formed by the elemental composition of the material is also conducive to enhancing electron transport and accelerating the efficiency of hydrogen evolution.Therefore,this study mainly prepared Ni-P/CNTs and Mn-NiP electrocatalyst materials.The main research contents are as follows.（1）The porous skeleton nickel powder was prepared from Ni-Al alloy by gas atomization and alkaline solution leaching method.The temperature and time of leaching reaction as well as the difference in the pore structure of the powders prepared under different particle sizes were discussed.It is concluded that the skeleton nickel powder prepared by this method has certain catalytic activity and can be used as an effective precursor material of the catalyst.（2）The Nickel phosphide arrays（Ni-P/CNTs）catalysts were prepared on the surface of porous nickel powders supported by carbon nanotubes by a simple and effective high-temperature phosphating method.Under acidic conditions,the Ni-P/CNTs catalyst prepared at 700℃for 60 min showed better catalytic activity than the catalysts prepared under other process conditions in this experiment.This may be related to the array morphology,electrochemically active surface area and P content of the catalyst.Also,the catalyst prepared under this condition also showed excellent stability of hydrogen evolution.This work will provide a promising pathway for designing various transition metal compounds and exploring the performance in catalysts for energy-related catalysis processes using porous metal materials.（3）Using the above method,the second metal manganese powder was doped into porous nickel powder and red phosphorus powder.After high-temperature phosphating,a kind of multiphase nickel phosphide(Ni₃P,Ni₂P,Ni₁₂P₅)catalyst material（Mn-NiP）with bimetallic composition was constructed.Benefiting from the regulation effect of doped Mn on the electronic structure of Ni and the mutual electronic interaction between Ni and P,the hydrogen evolution activity of the catalyst doped with an appropriate amount of Mn has increased.The hydrogen evolution activity of 3Mn-NiP in the full p H range was mainly explored.The results showed that the overpotentials required for 3Mn-NiP to generate 10 m A?cm^-2 current density in 0.5 M H₂SO₄ and 1.0 M KOH were 164 and 77 m V,respectively.It showed more excellent HER activity in an alkaline environment.At the same time,3Mn-NiP exhibited excellent electrochemical durability in an alkaline environment and showed no significant decrease in activity after the continuous test for 24 hours.更多还原