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石墨烯负载的超微Ru纳米颗粒催化NaBH_(4)水解制氢
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作者 张磊 范薇 +1 位作者 邹润 雷丽军 《广州化工》 CAS 2024年第19期41-44,84,共5页
氢能被认为是绿色、清洁的新型能源形式,在未来的“碳中和碳达峰”战略中扮演重要的作用。相比于液化储氢方式,固态储氢具有运输和储存安全,使用条件温和等优势。其中NaBH_(4)是目前固态储放氢中研究最为广泛和深入的一种。采用改进的... 氢能被认为是绿色、清洁的新型能源形式,在未来的“碳中和碳达峰”战略中扮演重要的作用。相比于液化储氢方式,固态储氢具有运输和储存安全,使用条件温和等优势。其中NaBH_(4)是目前固态储放氢中研究最为广泛和深入的一种。采用改进的液相沉积-气相还原法可控制备了平均粒径为1.1 nm的超微Ru/rGO催化剂,采用透射电子显微镜对其形貌和物相进行了表征。考察了催化剂的量、NaOH浓度、NaBH_(4)浓度和反应温度对NaBH_(4)水解产氢活性的影响。同时研究了催化剂的循环稳定性以及循环后Ru/rGO的形貌和Ru尺寸分布,该工作将其超微Ru催化剂催化NaBH_(4)水解制氢提供一定的理论和实践参考。 展开更多
关键词 nabh_(4)水解 产氢 超微纳米颗粒
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Mn掺杂CoB催化剂在NaBH_(4)液相释氢中的应用研究
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作者 田亚萍 陈一莹 +4 位作者 刘青翠 李云青 庞睿琪 李芳 李其明 《化学研究与应用》 CAS 北大核心 2024年第4期738-744,共7页
CoB非晶催化剂制作成本低,性能良好被广泛应用于NaBH4水解制氢反应中。本文通过液相共还原法制备了一种Co-Mn-B多元非晶合金催化剂,系统研究了过渡金属Mn掺杂对CoB非晶催化剂的影响,采用XRD、SEM、EDS和XPS等手段对Mn掺杂催化剂的晶相... CoB非晶催化剂制作成本低,性能良好被广泛应用于NaBH4水解制氢反应中。本文通过液相共还原法制备了一种Co-Mn-B多元非晶合金催化剂,系统研究了过渡金属Mn掺杂对CoB非晶催化剂的影响,采用XRD、SEM、EDS和XPS等手段对Mn掺杂催化剂的晶相结构、微观形貌和元素价态进行了系统分析,同时对催化剂进行了产氢性能测试,探究了Co-Mn-B催化剂催化NaBH4水解的催化活性和动力学参数。研究结果表明:大范围掺杂Mn得到的三元非晶催化剂依然保持了材料的非晶态结构,Mn掺杂能够明显降低催化剂非晶粒子的团聚现象;当掺杂摩尔比为5%时,Co-Mn-B三元非晶催化剂表现出了最佳的催化性能,在30℃条件下,其水解产氢速率可达1300 mL·min^(-1)·g^(-1);通过阿伦尼乌斯曲线可知,基于该催化剂硼氢化钠水解反应活化能为34.1 kJ·mol^(-1)。 展开更多
关键词 催化剂 nabh_(4) 制氢 硼化钴 掺杂
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Hydrogen generation from NaBH_(4) for portable proton exchange membrane fuel cell
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作者 Bingxue Sun Xingguo Li Jie Zheng 《Materials Reports(Energy)》 EI 2024年第1期69-78,共10页
Sodium borohydride(NaBH_(4)) is considered as the most potential hydrogen storage material for portable proton exchange membrane fuel cells(PEMFC)because of its high theoretical hydrogen capacity.However,the slow and ... Sodium borohydride(NaBH_(4)) is considered as the most potential hydrogen storage material for portable proton exchange membrane fuel cells(PEMFC)because of its high theoretical hydrogen capacity.However,the slow and poor kinetic stability of hydrogen generation from NaBH_(4) hydrolysis limits its application.There are two main factors influencing the kinetics stability of hydrogen generation from NaBH_(4).One factor is that the alkaline byproducts(NaBO_(2)) of the hydrolysis reaction can increase the pH of the solution,thus inhibiting the reaction process.It mainly happens in the NaBH_(4) solution hydrolysis system.Another factor is that the monotonous increase in reaction temperature leads to uncontrollable and unpredictable hydrolysis rates in the solid NaBH_(4) hydrolysis system.This is due to the excess heat generated from this exothermic reaction in the initial reaction of NaBH_(4) hydrolysis.In this perspective,we summarize the latest research progress in hydrogen generation from NaBH_(4) and emphasize the design principles of catalysts for hydrogen generation from NaBH_(4) solution and solid state NaBH_(4).The importance of carbon as catalyst support material for NaBH_(4) hydrolysis is also highlighted. 展开更多
关键词 nabh_(4)hydrolysis Hydrogen generation CATALYST KINETICS Carbon support materials
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Hydrogen release of NaBH_(4) below 60 ℃ with binary eutectic mixture of xylitol and erythritol additive
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作者 Yugang Shu Jiaguang Zheng +4 位作者 Chengguo Yan Ao Xia Meiling Lv Zhenxuan Ma Zhendong Yao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第7期225-234,共10页
NaBH_(4) was widely regarded as a low-cost hydrogen storage material due to its high-mass hydrogen capacity of approximately 10.8%(mass)and high volumetric hydrogen capacity of around 115 g·L^(–1).However,it exh... NaBH_(4) was widely regarded as a low-cost hydrogen storage material due to its high-mass hydrogen capacity of approximately 10.8%(mass)and high volumetric hydrogen capacity of around 115 g·L^(–1).However,it exhibits strong stability and requires temperatures above 500℃ for hydrogen release in practical applications.In this study,two polyhydric alcohols,xylitol and erythritol(XE),were prepared as a binary eutectic sugar alcohol through a grinding-melting method.This binary eutectic sugar alcohol was used as a proton-hydrogen carrier to destabilize NaBH_(4).The 19NaBH_(4)-16XE composite material prepared by ball milling could start releasing hydrogen at 57.5℃,and the total hydrogen release can reach over 88.8%(4.45%(mass))of the theoretical capacity.When the 19NaBH_(4)-16XE composite was pressed into solid blocks,the volumetric hydrogen capacity of the block-shaped composite could reach 67.2 g·L^(–1).By controlling the temperature,the hydrogen desorption capacity of the NaBH_(4)-XE composite material was controllable,which has great potential for achieving solid-state hydrogen production from NaBH_(4). 展开更多
关键词 HYDROGEN DESORPTION Binary mixture nabh_(4) XYLITOL ERYTHRITOL
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Ru/SiO_(2)催化NaBH_(4)还原苯制环己烷性能研究
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作者 孙海杰 彭智昆 +1 位作者 范义如 王小慧 《郑州大学学报(理学版)》 CAS 北大核心 2024年第3期27-32,共6页
通过浸渍原位还原法制备了Ru/SiO_(2)催化剂,考察了载体粒径和织构性质对Ru催化NaBH_(4)还原苯制环己烷性能的影响,并优化了反应条件。结果表明,NaBH_(4)还原苯制环己烷反应主要发生在催化剂的大孔和外表面上。不同粒径、不同用量SiO_(2... 通过浸渍原位还原法制备了Ru/SiO_(2)催化剂,考察了载体粒径和织构性质对Ru催化NaBH_(4)还原苯制环己烷性能的影响,并优化了反应条件。结果表明,NaBH_(4)还原苯制环己烷反应主要发生在催化剂的大孔和外表面上。不同粒径、不同用量SiO_(2)负载Ru催化NaBH_(4)产氢速率与它们催化NaBH_(4)还原苯制环己烷的收率趋势大致相同,说明苯是由NaBH_(4)在Ru上解离的活性氢还原的。当RuCl_(3)·3H_(2)O与SiO_(2)(50 nm)的物质的量之比为1∶12.8,RuCl_(3)·3H_(2)O、NaOH和NaBH_(4)的浓度分别为0.030 mol/L、0.053 mol/L和1.74 mol/L时,NaBH_(4)水解产生适宜的活性氢,还原RuCl_(3)·3H_(2)O生成适宜的金属Ru活性位,环己烷收率高达99.8%。 展开更多
关键词 二氧化硅 催化 载体效应 硼氢化钠 环己烷
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In situ formed Mg(BH_(4))_(2) for improving hydrolysis properties of MgH_(2)
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作者 Yongyang Zhu Mili Liu +6 位作者 liming Zeng Yin Wang Daifeng Wu Rui Li Qing Zhou Renheng Tang Fangming Xiao 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第3期1204-1214,共11页
The hydrolysis of MgH_(2) delivers high hydrogen capacity(15.2 wt%),which is very attractive for real-time hydrogen supply.However,the formation of a surface passivation Mg(OH)_(2) layer and the large excess of H_(2)O... The hydrolysis of MgH_(2) delivers high hydrogen capacity(15.2 wt%),which is very attractive for real-time hydrogen supply.However,the formation of a surface passivation Mg(OH)_(2) layer and the large excess of H_(2)O required to ensure complete hydrolysis are two key challenges for the MgH_(2) hydrolysis systems.Now,a low-cost method is reported to synthesize MgH_(2)@Mg(BH_(4))_(2) composite via ball-milling MgH_(2) with cheap and widely available B_(2)O_(3)(or B(OH)_(3)).By adding small amounts of B_(2)O_(3),the in-situ formed Mg(BH_(4))_(2) could significantly promote the hydrolysis of MgH_(2).In particular,the MgH_(2)–10 wt%B_(2)O_(3) composite releases 1330.7 mL·g^(−1) H_(2)(close to 80%theoretical hydrogen generation H_(2))in H_(2)O and 1520.4 mL·g^(−1) H_(2)(about 95%)in 0.5 M MgCl_(2) in 60 min at 26℃ with hydrolysis rate of 736.9 mL·g^(−1)·min^(−1) and 960.9 mL·g^(−1)·min^(−1) H_(2) during the first minute of the hydrolysis,respectively.In addition,the MgCl_(2) solution allows repeated use by filtering and exhibits high cycle stability(20 cycles),therefore leading to much reduced capacity loss caused by the excess H_(2)O.We show that by introducing B_(2)O_(3) and recycling the 0.5 M MgCl_(2) solution,the system hydrogen capacity can approach 5.9 wt%,providing a promising hydrogen generation scheme to supply hydrogen to the fuel cells. 展开更多
关键词 hydrolysis MgH_(2) Mg(BH_(4))_(2) Hydrogen generation B_(2)O_(3) MgCl_(2)
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Oxygen vacancy defects engineering on Cu-doped Co_(3)O_(4) for promoting effective COS hydrolysis 被引量:3
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作者 Guanyu Mu Yan Zeng +5 位作者 Yong Zheng Yanning Cao Fujian Liu Shijing Liang Yingying Zhan Lilong Jiang 《Green Energy & Environment》 SCIE EI CAS CSCD 2023年第3期831-841,共11页
The activation of H_(2)O is a key step of the COS hydrolysis,which may be tuned by oxygen vacancy defects in the catalysts.Herein,we have introduced Cu into Co_(3)O_(4) to regulate the oxygen vacancy defect content of... The activation of H_(2)O is a key step of the COS hydrolysis,which may be tuned by oxygen vacancy defects in the catalysts.Herein,we have introduced Cu into Co_(3)O_(4) to regulate the oxygen vacancy defect content of the catalysts.In situ DRIFTS and XPS spectra reveal that COS and H_(2)O are adsorbed and activated by oxygen vacancy.The 10 at%Cu doped Co_(3)O_(4) sample(10Cu-Co_(3)O_(4))exhibits the optimal activity,100%of COS conversion at 70℃.The improved oxygen vacancies of CueCo_(3)O_(4) accelerate the activation of H_(2)O to form active -OH.COS binds with hydroxyl to form the intermediate HSCO^(-)_(2),and then the activated-OH on the oxygen vacancy reacts with HSCO^(-)_(2) to form HCO^(-)_(3).Meanwhile,the catalyst exhibits high catalytic stability because copper species(Cu+/Cu^(2+))redox cycle mitigate the sulfation of Co_(3)O_(4)(Co^(2+)/Co^(3+)).Our work offers a promising approach for the rational design of cobalt-related catalysts in the highly efficient hydrolysis COS process. 展开更多
关键词 Oxygen vacancy COS hydrolysis In situ spectra Cu doped Co_(3)O_(4)
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M/Co_(3)O_(4)(M=Fe、Ni)的简易制备及其催化NaBH_(4)水解制氢
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作者 吴龙祥 杨茂 +3 位作者 张浩东 赵国栋 刘永辉 王小炼 《成都大学学报(自然科学版)》 2023年第3期298-306,共9页
为提高硼氢化钠水解放氢速率,采用简单易操作的微波辐射—多元醇法制备低成本负载型非贵金属催化剂M/Co_(3)O_(4)(M=Fe、Ni)催化硼氢化钠水解制氢.研究发现,M/Co_(3)O_(4)对硼氢化钠水解具有显著的催化作用,且Fe/Co_(3)O_(4)具有更好的... 为提高硼氢化钠水解放氢速率,采用简单易操作的微波辐射—多元醇法制备低成本负载型非贵金属催化剂M/Co_(3)O_(4)(M=Fe、Ni)催化硼氢化钠水解制氢.研究发现,M/Co_(3)O_(4)对硼氢化钠水解具有显著的催化作用,且Fe/Co_(3)O_(4)具有更好的催化性能.在催化剂添加量为12.5 wt.%,水料比为50 mL/g和水解温度为40℃的条件下,Fe/Co_(3)O_(4)催化硼氢化钠在10.3 min内的放氢量达2 445.4 mL/g,对应的放氢速率和产氢率分别为237.4 mL/(min·g)和94.1%. 展开更多
关键词 硼氢化钠 水解制氢 Fe/Co_(3)O_(4) Ni/Co_(3)O_(4)
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过渡金属氟化物改善2NaBH_(4)+MgH_(2)储氢体系的放氢热力学性能
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作者 郗森良 王晓军 +4 位作者 张同环 韩宗盈 高猛 周仕学 于昊 《材料工程》 EI CAS CSCD 北大核心 2022年第9期97-104,共8页
通过机械球磨法制备了2NaBH_(4)+MgH_(2)和2NaBH_(4)+MgH_(2)+0.1MF_(x)(M=Ni,Ti,Zr;x=2,3,4)储氢复合材料。分别通过扫描电子显微镜(SEM)、能谱分析仪(EDS)和X射线衍射(XRD)分析了复合材料的形貌、元素分布和晶体结构。另外,通过差示... 通过机械球磨法制备了2NaBH_(4)+MgH_(2)和2NaBH_(4)+MgH_(2)+0.1MF_(x)(M=Ni,Ti,Zr;x=2,3,4)储氢复合材料。分别通过扫描电子显微镜(SEM)、能谱分析仪(EDS)和X射线衍射(XRD)分析了复合材料的形貌、元素分布和晶体结构。另外,通过差示扫描量热法(DSC)和程序升温脱附(TPD)测试了材料的放氢热力学性质。结果表明,通过添加NiF_(2),TiF_(3)和ZrF_(4),分别将2NaBH_(4)+MgH_(2)的第一个放氢峰温降低了8.9,35.7℃和54.5℃。此外,放氢过程中出现的NaMgF_(3)相改变了第一个放氢过程的反应路径,并且改变了2NaBH_(4)+MgH_(2)的第二次放氢过程,使得第二个脱氢过程的峰温分别降低了18.0,31.1℃和34.1℃。添加NiF_(2),TiF_(3)和ZrF_(4)使2NaBH_(4)+MgH_(2)的放氢比例分别达到91.7%,91.9%和98.7%。其中ZrF_(4)对2NaBH_(4)+MgH_(2)的整个放氢过程显示出了最好的效果。因此,2NaBH_(4)+MgH_(2)+0.1ZrF_(4)可以作为燃料电池供氢系统的潜在应用体系。 展开更多
关键词 金属氟化物 2nabh_(4)+MgH_(2) 机械球磨法 热力学稳定性
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NaBH_(4)/MCl_(x)体系对液体端羧基氟橡胶的还原及还原机理 被引量:1
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作者 常云飞 廖明义 温佳明 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2022年第6期306-313,共8页
以液体端羧基氟橡胶(LTCFs)为原料,硼氢化钠与金属氯化物(NaBH_(4)/MCl_(x))为还原体系,采用一锅法成功将LTCFs还原为液体端羟基氟橡胶(LTHFs).研究了多种稀土金属氯化物(LaCl_(3),CeCl_(3),NdCl_(3)和SmCl_(3))和过渡金属氯化物(MnCl_(... 以液体端羧基氟橡胶(LTCFs)为原料,硼氢化钠与金属氯化物(NaBH_(4)/MCl_(x))为还原体系,采用一锅法成功将LTCFs还原为液体端羟基氟橡胶(LTHFs).研究了多种稀土金属氯化物(LaCl_(3),CeCl_(3),NdCl_(3)和SmCl_(3))和过渡金属氯化物(MnCl_(2),NiCl_(2),CoCl_(2)和CuCl_(2))对LTCFs还原效果的影响及变化规律.采用傅里叶变换红外光谱(FTIR)、核磁共振氢谱(^(1)H NMR)、核磁共振氟谱(^(19)F NMR)和化学滴定法对原料和产物的分子链结构和官能团含量进行了表征.结果表明,稀土金属MCl_(x)还原体系对LTCFs的还原效果均高于过渡金属MCl_(x)还原体系,LTCFs中的—C=C—和—COOH均可以被还原为—C—C—和—OH,其中NaBH_(4)/SmCl_(3)还原体系还原效率最高,达到92%.机理研究表明,NaBH_(4)/MCl_(x)对—COOH的还原性能与MCl_(x)中金属阳离子和羰基氧间的结合力有关,结合力越大越有利于—COOH的还原. 展开更多
关键词 液体端羧基氟橡胶 金属氯化物 硼氢化钠(nabh_(4)) 羧基 还原机理
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Na_(2)SO_(4)改性Co_(3)O_(4)催化NaBH_(4)-NH_(3)BH_(3)复合物水解放氢性能研究
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作者 刘永辉 张力丹 +4 位作者 杨茂 邓自萌 吴裕程 吴朝玲 王小炼 《化工新型材料》 CAS CSCD 北大核心 2022年第10期173-178,183,共7页
NaBH_(4)-NH_(3)BH_(3)复合物(xSB-AB,x=2,4,6,8)具有比单体更好的水解放氢性能,但在温和条件下的产氢效率仍然不够理想。将Na_(2)SO_(4)改性的Co_(3)O_(4)用于催化NaBH_(4)-NH_(3)BH_(3)复合物水解,发现它表现出比纯Co_(3)O_(4)更为优... NaBH_(4)-NH_(3)BH_(3)复合物(xSB-AB,x=2,4,6,8)具有比单体更好的水解放氢性能,但在温和条件下的产氢效率仍然不够理想。将Na_(2)SO_(4)改性的Co_(3)O_(4)用于催化NaBH_(4)-NH_(3)BH_(3)复合物水解,发现它表现出比纯Co_(3)O_(4)更为优异的催化性能。Na_(2)SO_(4)改性的Co_(3)O_(4)催化2NaBH_(4)-NH_(3)BH_(3)在40℃水解时,8min的产氢量达到了2430mL/g。结果表明:Na_(2)SO_(4)本身对NaBH_(4)-NH_(3)BH_(3)复合物水解无催化作用,但可能有利于Co_(3)O_(4)原位转化为具有高催化活性的Co-B合金,从而提升NaBH_(4)-NH_(3)BH_(3)复合物的放氢性能。 展开更多
关键词 nabh_(4)-NH_(3)BH_(3) Na_(2)SO_(4) Co_(3)O_(4) 水解
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SYNTHESIS AND CHARACTERIZATION OF POLY{4-[2-(tert-BUTYLDIMETHYLSILOXY)ETHYL]STYRENE}AND ITS HYDROLYSIS DERIVATIVE 被引量:1
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作者 郭文莉 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2009年第3期399-405,共7页
The living cationic polymerization of 4-[2-(tert-butyldimethylsiloxy)ethyl]styrene (TBDMES) was studied in methylcyclohexane (MeChx)/methylchloride (MeCl) (50/50 V/V) solvent mixture at -80 degrees C. The initiator 1,... The living cationic polymerization of 4-[2-(tert-butyldimethylsiloxy)ethyl]styrene (TBDMES) was studied in methylcyclohexane (MeChx)/methylchloride (MeCl) (50/50 V/V) solvent mixture at -80 degrees C. The initiator 1,1-diphenylethylene (DPE) capped 2-chloro-2,4,4-trimethylpentane (TMPCl) was formed in situ in conjunction with titanium tetrachloride (TiCl(4)). The Lewis acidity of TiCl(4) was decreased by the addition of titanium(IV) isopropoxide (Ti(OiPr)(4)) to accomplish living polymerization of TBDMES. Hydrolysis of poly(TBDMES) in the presence of tetra-butylammonium fluoride yielded poly[4-(2-hydroxyethyl)styrene] (poly(HOES)). FT-IR, NMR and DSC demonstrated the hydrolysis was complete. 展开更多
关键词 Living carbocationic polymerization Poly[4-(2-hydroxyethyl)styrene] hydrolysis Pendant hydroxyl groups
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钴基催化剂催化NaBH_(4)制氢研究进展 被引量:1
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作者 徐欢 于佳蕊 +2 位作者 曹中秋 王艳 张轲 《材料导报》 EI CAS CSCD 北大核心 2022年第5期122-132,共11页
氢气是清洁燃料,不会对环境产生任何有毒副产品,且氢气具有很高的能量密度,约为120 kJ/g,比石油的三倍还多,是燃料电池理想的替代能源载体。未来,氢气具有广阔的发展空间和应用前景,但氢的存储安全问题需要进一步解决,而化学储氢对实现... 氢气是清洁燃料,不会对环境产生任何有毒副产品,且氢气具有很高的能量密度,约为120 kJ/g,比石油的三倍还多,是燃料电池理想的替代能源载体。未来,氢气具有广阔的发展空间和应用前景,但氢的存储安全问题需要进一步解决,而化学储氢对实现这一目标起着至关重要的作用。NaBH_(4)作为储氢材料,其氢含量高达10.7%(质量分数),远高于其它化学品,且NaBH_(4)溶液可长期贮存,在有催化剂的情况下,其放氢速率可得到控制。虽贵金属催化剂具有优越的催化活性和稳定性,但由于资源有限且成本高,研究人员开始重点研究非贵金属催化剂。其中,钴基催化剂,因其活性高、比贵金属便宜以及储量丰富等优点而受到越来越多的关注,具有广阔的商业应用前景。然而钴的弱点之一是由于硼酸盐的强吸附作用使其表面钝化而失活,通过与金属合金化可以改变钴的电子结构,减少钴的吸附。钴基催化剂主要分为载体型催化剂和无载体型催化剂。无载体钴基催化剂表面积通常较小,且其在放热水解反应中容易团聚,导致催化性能降低和使用寿命减短。因此钴基活性组分通常负载于载体上,由于金属钴与催化剂载体间存在强相互作用以及与其它元素间的协同效应,使得钴基催化剂在硼氢化钠水解制氢过程中表现出较高的催化活性。此外,加入掺杂剂如B或P,以及与另一种过渡金属(Ni、Fe、Cu、Mo、Zn、W和Cr等)或稀土金属(Ce、Pr和La等)合金化也可以提高其催化效能。钴基催化剂有很多种,包括钴纳米颗粒、金属钴、钴盐及氧化钴等。本文综述了钴基催化剂用于催化NaBH_(4)水解的研究进展,主要包括NaBH_(4)水解原理、实验室测定NaBH_(4)水解制氢常用装置、钴基催化剂制备方法、钴基催化剂分类及钴基催化剂用于催化NaBH_(4)水解的影响因素;重点介绍了钴基-载体型催化剂催化NaBH_(4)水解制氢的研究进展,提出了目前钴基催化剂发展面临的问题并对未来钴基催化剂研究的发展方向进行了展望。 展开更多
关键词 nabh_(4) 钴基催化剂 制氢 催化活性
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Pd/CeO_(2)对2,4-二氯苯氧乙酸的液相催化加氢脱氯
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作者 牛夕阳 余诗慧 +1 位作者 杨娇娇 周娟 《东华大学学报(自然科学版)》 CAS 北大核心 2023年第2期136-143,149,共9页
采用NaBH4还原法分别制备了不同载体CeO_(2)、活性炭(AC)和石英砂(SiO_(2))的负载型Pd基催化剂。采用Zeta电位、X射线衍射、透射电子显微镜等手段对催化剂进行表征,并利用高活性Pd/CeO_(2)催化剂对2,4-二氯苯氧乙酸(2,4-D)进行液相加氢... 采用NaBH4还原法分别制备了不同载体CeO_(2)、活性炭(AC)和石英砂(SiO_(2))的负载型Pd基催化剂。采用Zeta电位、X射线衍射、透射电子显微镜等手段对催化剂进行表征,并利用高活性Pd/CeO_(2)催化剂对2,4-二氯苯氧乙酸(2,4-D)进行液相加氢脱氯反应研究。研究结果表明:载体对催化剂活性影响较大,其中Pd/CeO_(2)催化剂具有高等电点、较强的金属-载体相互作用以及Pd颗粒高分散度的活性特征;Pd/CeO_(2)催化剂对2,4-D的脱氯效果随Pd负载量增加而增加,随pH值的增加呈现先升高后降低的趋势;Pd/CeO_(2)催化剂对2,4-D的加氢脱氯反应符合Langumir-Hinshelwood模型,表明2,4-D在催化剂表面的吸附是反应的速率控制步骤,且Pd/CeO_(2)对不同的污染物都表现出较高的液相加氢还原活性。 展开更多
关键词 液相催化加氢脱氯 2 4-二氯苯氧乙酸 Pd/CeO_(2) nabh_(4)还原法
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Pig Liver Esterase-catalyzed Hydrolysis of Three Diesters of meso-Bicyclic Dicarboxylic Acid and Three Tetraesters of Tetrahydrofuran -2,3,4,5-tetracarboxylic Acid
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作者 MA Guang-En and Tamm Ch. (National Institutes of Pharmaceutical Research & Development, Beijing 102206, P. R. China Institut fur Organishe Chemie der Universitat Basel, CH-4056 Basel Switzerland) 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2000年第4期369-374,共6页
Three diesters of exo- syn-meso-oxabicyclo (2, 2, 1 ) -hept- 5- ene- 2, 3- dicarboxylic acid and three tetraesters of tetrahydrofuran-2, 3, 4, 5-tetracarboxylic acid were synthesized and tested with enantioselective h... Three diesters of exo- syn-meso-oxabicyclo (2, 2, 1 ) -hept- 5- ene- 2, 3- dicarboxylic acid and three tetraesters of tetrahydrofuran-2, 3, 4, 5-tetracarboxylic acid were synthesized and tested with enantioselective hydrolysis catalyzed by pig liver esterase(PLE). The results of the PLEcatalyzed hydrolysis were discussed. 展开更多
关键词 Oxabicyclo(2 2 1 )-hept-5-ene-2 3-dicarboxylic acid Tetrahydrofuran-2 3 4 5- tetracarboxylic acid ESTERIFICATION hydrolysis Pig liver esterase(PLE)
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Mixed-Ligand Ni(Ⅱ), Co(Ⅱ) and Fe(Ⅱ) Complexes as Catalysts for Esterification of Biomass-Derived Levulinic Acid with Polyol and in Situ Reduction via Hydrogenation with NaBH_(4)
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作者 Md.Anwar Hossain Lee Hwei Voon 《Journal of Renewable Materials》 SCIE 2019年第8期731-748,共18页
Synthesizing polyol-based ester from biomass feedstocks for the preparation of biolubricant overcomes the dependence on petroleum oil usage.Albeit biomass-derived bio-oil is an alternative for the production of polyol... Synthesizing polyol-based ester from biomass feedstocks for the preparation of biolubricant overcomes the dependence on petroleum oil usage.Albeit biomass-derived bio-oil is an alternative for the production of polyol ester,upgrading is essential prior to use as biolubricant.Levulinic acid(LA),obtained from bio-oil was applied for the catalytic esterification with two polyols,e.g.,trimethylolpropane(TMP)and pentaerythritol(PE),in the presence of mixed-ligand Ni(Ⅱ),Co(Ⅱ),and Fe(Ⅱ)complexes as catalyst.New mixed-ligand coordination complexes with empirical formula;[Ni(Phe)(Bpy)Cl].H2O,[Co(Phe)(Bpy)Cl].H2O,and[Fe(Phe)(Tyr)Cl].H2O were synthesized by the reaction of ligands[L-phenylalanine(Phe),4,4'-bipyridine(Bpy),and L-tyrosine(Tyr)]with metal chloride salts and characterized by elemental analysis,magnetic susceptibility,FTIR,TGA/DTA,powder-XRD,and SEM techniques.This study aims to investigate the catalytic activities of the complexes via esterification reaction of levulinic acid with trimethylolpropane and pentaerythritol.In addition,these catalysts were further employed for the in situ hydrogenation of levulinate esters via NaBH_(4) at room temperature upon refluxing.Indeed,the iron(Ⅱ)complex was more potential,exhibiting its efficiency as a homogeneous catalyst for esterification-hydrogenation reaction for synthesizing ester-based oils. 展开更多
关键词 Biomass esterification-hydrogenation mixed-ligand complex nabh_(4) reduction
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Preparation of microsized single-crystalline Co_3O_4 by high-temperature hydrolysis
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作者 李启厚 刘智勇 +1 位作者 刘志宏 胡雷 《Journal of Central South University》 SCIE EI CAS 2011年第4期993-997,共5页
Microsized single-crystalline Co3O4 has been synthesized by high-temperature hydrolysis of CoCD2H20 at 600℃. The samples were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) an... Microsized single-crystalline Co3O4 has been synthesized by high-temperature hydrolysis of CoCD2H20 at 600℃. The samples were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results reveal that the as-prepared powders are microsized single-crystalline CO3O4 with cubic spinel structure. An increase in the high-temperature hydrolysis time results in the evolution of particle shapes from cube to quasi-sphere, and then to octahedron. The effect of NaCl additive on the surface morphologies of Co3O4 particles was experimentally investigated. The results indicate that the NaCl additive acts as an inert disperse phase in the high-temperature hydrolysis, and prevents the aggregation of Co3O4 particles effectively. 展开更多
关键词 CO3O4 crystal structure hydrolysis surface morphology
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Preparation of Fe_(3)O_(4) Film by in-situ Oxidative Hydrolysis on Chitosan
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作者 Suwei YAO Zhaohui ZHAO Weiguo ZHANG Hongzhi WANG 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2006年第3期329-332,共4页
The Fe3O4 films were prepared by in-situ oxidative hydrolysis on chitosan. The structures and characteristics of the prepared Fe3O4 films were investigated by X-ray diffractometry (XRD), scanning electron microscopy... The Fe3O4 films were prepared by in-situ oxidative hydrolysis on chitosan. The structures and characteristics of the prepared Fe3O4 films were investigated by X-ray diffractometry (XRD), scanning electron microscopy (SEM), atom force microscopy (AFM), vibrating sample magnetometry (VSM) and thermogravimetric-differentia thermal analysis (TG-DTA). The results show that, (1) the as-synthesized Fe3O4 films are pure Fe3O4 with cubic inverse spinel structure; (2) the network structured film can be obtained at lower temperature, and the compact particle film at higher temperature; (3) the prepared Fe3O4 films are super-paramagnetic, and the saturation magnetization is improved with increasing the reaction temperature, which is 49.03 emu/g at 80℃; (4) the temperature of phase transformation from Fe3O4 to a-Fe2O3 is about 495℃. Besides, the formation mechanism of Fe3O4 film was also proposed. 展开更多
关键词 Fe3O4 film IN-SITU Oxidative hydrolysis CHITOSAN
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High-Order Elastic Constants and Anharmonic Properties of NaBH_(4):First-Principles Calculations
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作者 ZHANG Xiao-Dong JIANG Zhen-Yi +2 位作者 ZHOU Bo HOU Zhu-Feng HOU Yu-Qing 《Chinese Physics Letters》 SCIE CAS CSCD 2011年第7期236-238,共3页
We present theoretical studies for second-and third-order elastic constants in NaBH_(4) based on ab initio calculations.Our calculated second−order elastic constants agree well with available experimental results.The ... We present theoretical studies for second-and third-order elastic constants in NaBH_(4) based on ab initio calculations.Our calculated second−order elastic constants agree well with available experimental results.The anharmonic properties of NaBH_(4),such as pressure derivative of the second−order elastic constants and the Grüneisen constants for long-wavelength acoustic mode γ(q,j),are characterized using the third-order elastic constants. 展开更多
关键词 CONSTANTS nabh_(4) CONSTANTS
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Promoted hydrolysis performances and mechanism of Si-NaBH4-AlCl_(3) in deionized water
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作者 Zhao Feng Chaoling Wu +3 位作者 Shuang Zhong Yungui Chen Hui Chen Yao Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2020年第12期3136-3144,共9页
Si-based hydrolysis material system can be used in mobile/portable hydrogen source applications connected to fuel cells but is limited by alkaline solutions.In the present research,we reported an acid/alkaline free hy... Si-based hydrolysis material system can be used in mobile/portable hydrogen source applications connected to fuel cells but is limited by alkaline solutions.In the present research,we reported an acid/alkaline free hydrolysis systemcombining siliconwith NaBH4.Sampleswith different ratios between Si and NaBH4 are prepared via high energy ball milling and hydrolyzed in deionized water at different temperatures.Synergetic effect between silicon and NaBH4was found in the hydrolysis process.2Si-NaBH4 sample displays the best hydrolysis performances with the hydrogen yield of 1594 ml·g^(−1) in deionized water at 70℃.Thereafter,AlCl3 is added into the 2Si-NaBH4 sample to further improve its comprehensive properties.The effect of AlCl3 content and promotion mechanism of the reaction are explored.2Si-NaBH4-5 wt% AlCl3 sample shows a significant improvement with a high hydrogen yield of 1689 ml·g^(−1) in deionized water at 70℃ and a corresponding conversion rate of 95.8%,indicating that the Si-NaBH4-AlCl3 composite is promising to be a hydrogen source in applications of mobile/portable fuelcell-powered facilities. 展开更多
关键词 hydrolysis Hydrogen generation Si-nabh4-AlCl_(3)composite Synergetic effect
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