CoB/CeO2催化剂的优化制备及在NaBH4液相制氢中的应用  

Preparation of CoB/CeO catalysts for hydrogen generation from liquid NaBH solution

作　　者：刘力魁 刘威[1] 李佳[1] 李芳[1] 李其明[1] LIU Likui;LIU Wei;LI Jia;LI Fang;LI Qiming(School of Petrochemical Engineering,Liaoning Shihua University,Fushun 113001,Liaoning,China)

机构地区：[1]辽宁石油化工大学石油化工学部,辽宁抚顺113001

出　　处：《化工进展》2020年第8期3095-3101,共7页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(21201096,21703091);辽宁省科技厅计划指导项目(2019-ZD-0058);辽宁省教育厅一般项目(L2019009)。

摘　　要：为了提高硼氢化钠水解催化剂的活性与稳定性,本文采用化学还原和焙烧后处理制备了一系列CoB/CeO2负载型催化剂,探究了该催化剂在NaBH4液相释氢中的催化性能。通过扫描电镜、X射线衍射、X射线光电子能谱等表征手段分析了催化剂结构和组成,并结合催化剂在NaBH4水解制氢中的催化活性,研究了不同焙烧后处理方式对CoB/CeO2负载型催化剂体系的作用规律。结果表明CoB负载到CeO2载体表面后催化剂仅呈现了CeO2载体的萤石相结构,但针对活性组分对比分析表明在高温下(空气和氮气)仍然出现了CoB的显著晶化。CoB/CeO2在空气和氮气焙烧气氛下都有利于提高CoB活性组分在CeO2载体表面的固载强度,但是二者呈现出不同的微观形貌。在NaBH4液相释氢中,CoB/CeO2-air和CoB/CeO2-N2展示了显著不同的催化活性,并且随着焙烧温度的提高,二者催化性能差异更加明显,温度升高后CoB/CeO2-air催化活性逐步降低,并在500℃左右完全失活,而CoB/CeO2-N2则呈现了趋于稳定的催化活性。To improve the catalysts’ activity of NaBH4 hydrolysis,a series of CoB/CeO2 supported catalysts were prepared by a combined chemical reduction and post-calcination method.Catalytic activities of these catalysts in the hydrogen generation from NaBH4 hydrolysis were investigated.Phase structure and composition of the CoB/CeO2 supported catalysts were characterized by SEM,XRD and XPS,and the results were correlated with their catalytic performance.The experimental results indicated that the as-prepared supported CoB/CeO2 catalysts exhibited typical fluorite phase structure only,but the comparative analysis showed that significant crystallization of CoB still occurred at high temperature.CoB/CeO2 catalysts treated under air and nitrogen can have improved immobilization strength,but they displayed different surface morphologies.When used in hydrogen generation from liquid NaBH4 hydrolysis,CoB/CeO2-air and CoB/CeO2-N2 exhibited obviously different catalytic activities.Moreover,this difference tends to be more obvious at elevated treatment temperature.With the increase of calcination temperature,the catalytic activity of CoB/CeO2-air gradually decreased and even completely disappeared at 500℃,whereas CoB/CeO2-N2 maintained the catalytic activity more stably.

关 键 词：催化剂 水解 制氢 载体 活性 

分 类 号：O643.3[理学—物理化学]