Fe/Co/Ni基催化剂制备及氨分解制氢性能  

Synthesis of Fe/Co/Ni based catalysts and NH 3 cracking performance for H_(2)production

作　　者：胡利华 陈境烨 童金明 何勇[2] 许岩韦 翁武斌[2] 王智化[2] HU Lihua;CHEN Jingye;TONG Jinming;HE Yong;XU Yanwei;WENG Wubin;WANG Zhihua(Everbright Environmental Technology Research Institute(Shenzhen)Ltd.,Shenzhen 518000,China;State Key Laboratory of Clean Energy Utilization,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]光大环保技术研究院(深圳)有限公司,广东深圳518000 [2]浙江大学能源清洁利用国家重点实验室,浙江杭州310027

出　　处：《洁净煤技术》2024年第8期1-10,共10页Clean Coal Technology

基　　金：国家自然科学基金资助项目(52125605)。

摘　　要：氢能因具有高效、清洁、可持续等优点,被认为是最具发展潜力的化石燃料替代能源。氨气作为一种储氢材料,具有高储氢密度、易液化等优点,因此氨分解制氢是一种理想的氢气制备方法。开发中低温下高选择性、高活性、廉价的氨分解催化剂具有重要意义。Ru基催化剂是氨分解活性最高的单金属催化剂,但成本较高,Fe、Co、Ni等过渡金属是Ru的合适替代品。与此同时,催化剂载体的选择是制备高效催化剂的关键因素。采用浸渍法制备了以γ-Al_(2)O_(3)、SiO_(2)、MgO、TiO_(2)为载体,Fe、Co、Ni为活性组分的系列氨分解催化剂,在氨催化裂解反应平台开展了反应温度400~700℃、空速比18000 h^(-1)条件下的催化剂活性评估试验,并在此基础上对合成的催化剂进行了XRD、BET、SEM、TEM等表征分析,探究不同活性组合、载体种类、反应温度等因素对氨催化裂解的影响。结果表明,Ni/Al_(2)O_(3)催化剂活性最高,空速为18000 h^(-1)、600℃时的氨分解率达91.67%,650℃时可基本实现氨的完全分解。除SiO_(2)载体外,Ni基催化剂的活性整体高于Fe和Co基催化剂。表征发现在Ni/γ-Al_(2)O_(3)催化剂存在NiO与γ-Al_(2)O_(3)形成的复合氧化物结构,同时γ-Al_(2)O_(3)载体更大的比表面积和孔体积有利于提高氨分解转化率。Hydrogen energy is considered to be the most promising alternative energy source to fossil fuels due to its advantages of efficient,clean and sustainable.As a kind of hydrogen storage material,ammonia has many advantages such as high hydrogen storage density and easy liquefaction,so hydrogen production by ammonia decomposition is an ideal method for hydrogen preparation.The development of highly selective,active and inexpensive catalysts for ammonia decomposition at low and medium temperatures is of great significance for the development and utilization of hydrogen energy.Ru-based catalysts are the most active single-metal catalysts for ammonia decomposition,but their costs are high,and transition metals such as Fe,Co and Ni are suitable substitutes for Ru.Meanwhile,the choice of catalyst carrier is a key factor in the preparation of efficient catalysts.A series of ammonia decomposition catalysts withγ-Al 2O 3,SiO_(2),MgO and TiO_(2)as the carriers and Fe,Co and Ni as the active components were prepared by the impregnation method,and the catalyst activity evaluation test was carried out in the ammonia catalytic cracking reaction platform at 400℃to 700℃and the air-velocity ratios of 18000 h^(-1).On the basis of this,the synthesized catalysts were characterized by XRD,BET,SEM and TEM to investigate the effects of different activity combinations,carrier types,reaction temperatures and other factors on the ammonia catalytic cracking.The results show that the Ni/Al_(2)O_(3)catalyst has the highest activity,and the ammonia decomposition rate reaches 91.67%at 18000 h^(-1)and 600℃,and the complete decomposition of ammonia could be basically achieved at 650℃.The activities of Ni-based catalysts are overall higher than those of Fe-and Co-based catalysts,except for SiO_(2)carrier.Characterisation reveales that a composite oxide structure formed by NiO andγ-Al_(2)O_(3)existed in the Ni/γ-Al_(2)O_(3)catalysts,while the larger specific surface area and pore volume of theγ-Al_(2)O_(3)carriers are conducive to the im

关 键 词：氨 氢 氨分解 过渡金属催化剂 载体 

分 类 号：O643[理学—物理化学]