不同前体制备Ni催化剂及其在硫碘制氢中催化分解HI的性能  

Ni impregnated catalyst in HI decomposition in sulfur-iodine thermochemical cycle for hydrogen production

作　　者：傅广实 钱燕[1] 王智化[1] 王丽建 张彦威[1] 刘建忠[1] 岑可法[1] FU Guangshi;QIAN Yan;WANG Zhihua;WANG Lijian;ZHANG Yanwei;LIU Jianzhong;CEN Kefa(State Key Laboratory of Clean Energy Utilization,Zhejiang University,Hangzhou 310027,Zhejiang,China)

机构地区：[1]浙江大学能源清洁利用国家重点实验室,浙江杭州310027

出　　处：《化工进展》2018年第11期4308-4314,共7页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金优秀青年科学基金(51422605);高等学校学科创新引智计划(B08026)项目

摘　　要：硫碘制氢是目前最有潜力的大规模低成本制氢方法之一。HI催化分解是硫碘制氢的关键步骤。本文采用4种具有代表性的镍盐前体——硝酸镍[Ni(NO_3)_2]、乙酸镍[Ni(CH_3COO)_2]和两种有机金属络合镍(乙酰丙酮镍[Ni(acac)_2]和亚硝酸三乙二胺合镍[Ni(en_3)](NO_2)_2)制备Ni催化剂,考察了不同镍盐前体对制备的Ni催化剂特性的影响规律以及Ni催化剂在HI催化分解中的性能。采用了BET、XRD和TEM等分析测试技术对制备的Ni催化剂进行了表征。研究结果表明,镍盐前体对制备的Ni催化剂的分散度、催化活性以及催化稳定性有重要的影响。以Ni(NO_3)_2和[Ni(en_3)](NO_2)_2为前体制备的Ni催化剂具有良好的Ni金属分散度,Ni颗粒分散均匀且尺寸较小。由于高温和强腐蚀的反应环境(HI-I_2-H_2O体系),Ni催化剂经过反应都会出现不同程度的失活。以[Ni(en_3)](NO_2)_2为前体制备的Ni催化剂表现出最好的催化活性和稳定性,有望成为未来大规模硫碘制氢系统中HI分解的催化剂。HI decomposition reaction is a key step in the sulfur-iodine thermochemical water splitting cycle for hydrogen production,which is considered as one of the most promising thermochemical cycles for hydrogen production driven by solar or nuclear energy.The low reaction rate of the HI decomposition shows the necessity of using catalyst.In order to develop high active and reliable catalyst for the HI decomposition,four Ni impregnated on activated carbon catalysts were prepared by using different precursors(e.g.nickel nitrate,nickel acetate tetrahydrate,nickel(Ⅱ)acetylacetonate,and[Ni(en3)](NO2)2(en,ethylenediamine))in this study to investigate the effect of the precursor on the properties of the catalyst and the reactivity in HI decomposition.All the catalysts were prepared by an incipient-wetness impregnation method and calcined at 823K in the presence of hydrogen atmosphere for 3h with a heating rate of 5K/min.The theoretical content of the nickel in the prepared catalysts was 12%.Their catalytic performance was measured for HI decomposition at 673K and 773K,respectively.Nitrogen phsisorption,X-ray diffraction,and transmission electron microscope were employed to characterize the catalysts.The results of characterizations indicated that precursors significantly influenced the properties of catalysts(e.g.Ni clusters dispersion,morphologies of catalysts)and catalytic performance in HI decomposition.The Ni catalyst prepared using[Ni(en3)](NO2)2 demonstrated the optimal catalytic reactivity and stability in HI decomposition and could be a good choice for large-scale SI cycle hydrogen production system.

关 键 词：制氢 再生能源 催化剂 硫碘循环 

分 类 号：TK91[动力工程及工程热物理]