摘要
采用浸渍-化学还原法制备了Ru/ZrO_(2)催化剂,并考察了钌负载量、硼氢化钠的用量、还原温度以及反应条件对催化剂Ru/ZrO_(2)催化BH_(3)NH_(3)水解产氢的影响。结果表明,在钌的负载量为0.4%,钌与还原剂硼氢化钠的物质的量比为1∶1.6,还原温度为303 K时,Ru微晶尺寸为3.2 nm,Ru/ZrO_(2)催化剂催化BH_(3)NH_(3)水解产氢的转化频率TOF(turn over frequency)为38.4 mol/mol(Ru)·min。搅拌转速为450 r/min时,外扩散限制消除,产氢速率最大;产氢速率与催化剂用量成正比,氨硼烷水解产氢反应由催化剂界面反应控制;随着反应温度的升高,氨硼烷产氢速率系数增大,副产物偏硼酸钠越易从催化剂表面脱附,产氢速率越大。反应动力学计算表明Ru/ZrO_(2)催化剂催化BH_(3)NH_(3)水解产氢速率与氨硼烷浓度无关,活化能为66 kJ/mol。
ZrO_(2) supported Ru catalysts were synthesized with an impregnation-chemical reduction method using NaBH 4 as the reducing agent.The prepared catalysts were evaluated for the hydrogen generation via catalytic hydrolysis of BH_(3)NH_(3).Effect of catalytic activity was investigated by varying the impregnated Ru loading,amount of reducing agent,reduction temperature as well as the reaction conditions.It was found that the TOF(Turnover Frequency)of 38.4 mol/mol(Ru)·min was achieved by adjusting Ru loading to 0.4 at 303 K of reaction temperature,while the molar ratio of Ru to NaBH 4 was 1:1.6.The Ru particle size of 3.2 nm was observed.Moreover,when the stirring speed was 450 r/min,external diffusion could be eliminated,leading to the highest reaction rate towards hydrogen generation.In addition,catalytic activity increased with enhancing the amount of used catalyst,indicating that catalytic hydrolysis of BH_(3)NH_(3) towards hydrogen production was controlled by the interfacial reaction over the catalyst surface.Furthermore,with the reaction temperature increasing,it gets more suitable for the desorption of NaBO_(2),the side product of hydrolysis of BH_(3)NH_(3),from the catalyst surface.This results in the enhancement of the reaction rate towards hydrogen formation.According to the kinetic calculation,it suggests that the reaction rate of hydrolysis of BH_(3)NH_(3) towards hydrogen generation over Ru/ZrO_(2) is irrelevant to the concentration of BH_(3)NH_(3).The activation energy is 66 kJ/mol.
作者
孙海杰
刘欣改
陈志浩
陈凌霞
张路
梅洋洋
SUN Haijie;LIU Xingai;CHEN Zhihao;CHEN Lingxia;ZHANG Lu;MEI Yangyang(School of Chemistry and Chemical Engineering,Zhengzhou Normal University,Zhengzhou Henan 450044,China;Zhengzhou Tobacco Research Institute,China National Tobacco Corporation,Zhengzhou Henan 450001,China)
出处
《广西师范大学学报（自然科学版）》
CAS
北大核心
2021年第3期92-101,共10页
Journal of Guangxi Normal University:Natural Science Edition
基金
国家自然科学基金(21908203)
国家级大学生创新创业训练计划项目(201912949002)
河南省科技攻关项目(192102210139)
河南省高等学校青年骨干教师培养计划(2019GGJS252)
河南省高等学校重点科研项目(18A150018)
郑州师范学院环境催化科研创新团队项目(702010)。
关键词
钌
二氧化锆
催化剂
氨硼烷
产氢
Ru
ZrO_(2)
catalyst
ammonia borane
hydrogen generation
