分别采用乙二醇(EG)和H2O为溶剂,通过NaBH4还原法在酸性pH≤2和碱性pH≥12条件下制备了铂担载量为20%(质量分数)的Pt/C催化剂,利用TEM、CV及LSV等方法对催化剂进行了表征与测试,考察了EG在NaBH4还原法中对铂纳米颗粒的稳定作用。结果表...分别采用乙二醇(EG)和H2O为溶剂,通过NaBH4还原法在酸性pH≤2和碱性pH≥12条件下制备了铂担载量为20%(质量分数)的Pt/C催化剂,利用TEM、CV及LSV等方法对催化剂进行了表征与测试,考察了EG在NaBH4还原法中对铂纳米颗粒的稳定作用。结果表明,EG作溶剂、碱性pH≥12时,通过NaBH4还原法制备得到了平均粒径约2.5nm、粒径分布窄、在碳载体上分散均匀的Pt/C催化剂;该催化剂的电化学比表面为74.4m2/g Pt,0.8V vs NHE时通过LSV得到的单位质量铂对甲醇电催化氧化的电流密度为229.1mA/mg Pt,分别是相同条件下H2O作溶剂时制备得到的Pt/C催化剂的5.倍和5.3倍。展开更多
In this work,a series of chitin-supported Ru catalysts,composed of ultrasmall Ru nanoparticles supported on the chitin nanofibers,with different Ru content from 0.07 wt%to 0.93 wt%,are fabricated.Results from catalyze...In this work,a series of chitin-supported Ru catalysts,composed of ultrasmall Ru nanoparticles supported on the chitin nanofibers,with different Ru content from 0.07 wt%to 0.93 wt%,are fabricated.Results from catalyzed NaBH4 hydrolysis experiments indicate that the catalytic activity of the fabricated chitin-supported Ru catalysts increases gradually with the decreasing of Ru content.The rate of hydrogen generation from NaBH4 hydrolysis catalyzed by the catalyst with 0.07 wt%Ru content is as high as 55.29 L min 1 gRu-1 at 30℃,and this reaction exhibits activation energy of 39.16 kJ/mol.The augment of NaBH4 dosage in the experiments does not weaken the catalytic activity.In addition,the fabricated chitin-supported Ru catalysts show excellent durability in NaBH4 hydrolysis,with only 9.2%activity loss after used for 20 cycles.With excellent catalytic activity and durability,the as-obtained Ru catalysts provide a promising choice for promoting hydrogen production from NaBH4 hydrolysis.展开更多
Ru and Co are highly dispersed on the surface of TiO2 nanopa rticles with an easy coprecipitation method to fabricate a novel Ru-based catalyst(Ru/Co-TiO2).The fabricated Ru/Co-TiO2 catalyst exhibits superior catalyti...Ru and Co are highly dispersed on the surface of TiO2 nanopa rticles with an easy coprecipitation method to fabricate a novel Ru-based catalyst(Ru/Co-TiO2).The fabricated Ru/Co-TiO2 catalyst exhibits superior catalytic performance for promoting NaBH4 hydrolysis in alkaline medium,showing an impressive hydrogen generation rate per gram Ru as high as 172 L min-1 gRu-1 which is better than most of recently reported Ru-based catalysts.In addition,the fabricated Ru/Co-TiO2 catalyst also shows excellent du rability in cycle use,with only 2.9% activity loss after being used for 5 cycles.These advantages make the developed Ru/Co-TiO2 catalyst a potential choice for promoting hydrogen generation from NaBH4 hydrolysis.展开更多
The feasibility of using liquid nitrogen cold trap （LNCT） for the removal of water vapour and alkaline mist from the hydrogen gas stream which is generated from the catalytic and acidic decomposition of sodium boroh...The feasibility of using liquid nitrogen cold trap （LNCT） for the removal of water vapour and alkaline mist from the hydrogen gas stream which is generated from the catalytic and acidic decomposition of sodium borohydride is investigated. Practically, the target application is mobile fuel cells based on hydrogen production from storage in chemical hydrides. The LNCT would be used as a one step purification method with less cost and space requirements instead of applying the conventional purification techniques. Two catalysts were investigated for the production of hydrogen from the aqueous solution of NaBH4 in a small scale packed bed reaction column. The hydrogen generated from the catalytic decomposition of NaBH4 was accompanied by limited quantity of water vapour and alkaline mist. Nonetheless, higher quantities were generated when applying the acidic decomposition of NaBH4 and consequently the utilization of LNCT for H2 purification has proved useful and lead to a reduction in the content of these impurities; thereby the concentration of hydrogen in the outlet stream has increased.展开更多
A combination of sodium borohydride and a catalytic amount of indium（Ⅲ） chloride in acetonitrile reduces imines formed in-situ from aldehydes and amines to the corresponding functionalised secondary and tertiary am...A combination of sodium borohydride and a catalytic amount of indium（Ⅲ） chloride in acetonitrile reduces imines formed in-situ from aldehydes and amines to the corresponding functionalised secondary and tertiary amines in moderate to good yields. Noteworthy is that highly chemoselective reactions were achieved in the presence of other functional groups such as halogens, carbon-carbon double bonds and hydroxyl groups.展开更多
Carbon nanotubes(CNTs)supported CoB and CoBSn catalysts were synthesized for hydrogen production via NaBH4 hydrolysis.The roles of Sn-promoter and the effect of CNTs treatment on CoB catalysts were evaluated and discu...Carbon nanotubes(CNTs)supported CoB and CoBSn catalysts were synthesized for hydrogen production via NaBH4 hydrolysis.The roles of Sn-promoter and the effect of CNTs treatment on CoB catalysts were evaluated and discussed.It is found that after the addition of Sn promoter,the specific surface area and the generation of active CoB phase are increased,while the oxidation treatment of CNTs results in more loading amounts of active components and enrichment of electron at active sites as well as large surface area.Consequently,the Sn-doped CoB catalysts supported on CNTs with oxidation treatment exhibits a significantly improved activity with a high H_(2)generation rate of 2640 mL/(min·g).Meanwhile,this catalyst shows a low activation energy of 43.7 kJ/mol and relatively high reusability.展开更多
文摘分别采用乙二醇(EG)和H2O为溶剂,通过NaBH4还原法在酸性pH≤2和碱性pH≥12条件下制备了铂担载量为20%(质量分数)的Pt/C催化剂,利用TEM、CV及LSV等方法对催化剂进行了表征与测试,考察了EG在NaBH4还原法中对铂纳米颗粒的稳定作用。结果表明,EG作溶剂、碱性pH≥12时,通过NaBH4还原法制备得到了平均粒径约2.5nm、粒径分布窄、在碳载体上分散均匀的Pt/C催化剂;该催化剂的电化学比表面为74.4m2/g Pt,0.8V vs NHE时通过LSV得到的单位质量铂对甲醇电催化氧化的电流密度为229.1mA/mg Pt,分别是相同条件下H2O作溶剂时制备得到的Pt/C催化剂的5.倍和5.3倍。
基金Chengdu University of Technology(No.10912-2019KYQD07208)。
文摘In this work,a series of chitin-supported Ru catalysts,composed of ultrasmall Ru nanoparticles supported on the chitin nanofibers,with different Ru content from 0.07 wt%to 0.93 wt%,are fabricated.Results from catalyzed NaBH4 hydrolysis experiments indicate that the catalytic activity of the fabricated chitin-supported Ru catalysts increases gradually with the decreasing of Ru content.The rate of hydrogen generation from NaBH4 hydrolysis catalyzed by the catalyst with 0.07 wt%Ru content is as high as 55.29 L min 1 gRu-1 at 30℃,and this reaction exhibits activation energy of 39.16 kJ/mol.The augment of NaBH4 dosage in the experiments does not weaken the catalytic activity.In addition,the fabricated chitin-supported Ru catalysts show excellent durability in NaBH4 hydrolysis,with only 9.2%activity loss after used for 20 cycles.With excellent catalytic activity and durability,the as-obtained Ru catalysts provide a promising choice for promoting hydrogen production from NaBH4 hydrolysis.
文摘Ru and Co are highly dispersed on the surface of TiO2 nanopa rticles with an easy coprecipitation method to fabricate a novel Ru-based catalyst(Ru/Co-TiO2).The fabricated Ru/Co-TiO2 catalyst exhibits superior catalytic performance for promoting NaBH4 hydrolysis in alkaline medium,showing an impressive hydrogen generation rate per gram Ru as high as 172 L min-1 gRu-1 which is better than most of recently reported Ru-based catalysts.In addition,the fabricated Ru/Co-TiO2 catalyst also shows excellent du rability in cycle use,with only 2.9% activity loss after being used for 5 cycles.These advantages make the developed Ru/Co-TiO2 catalyst a potential choice for promoting hydrogen generation from NaBH4 hydrolysis.
文摘The feasibility of using liquid nitrogen cold trap （LNCT） for the removal of water vapour and alkaline mist from the hydrogen gas stream which is generated from the catalytic and acidic decomposition of sodium borohydride is investigated. Practically, the target application is mobile fuel cells based on hydrogen production from storage in chemical hydrides. The LNCT would be used as a one step purification method with less cost and space requirements instead of applying the conventional purification techniques. Two catalysts were investigated for the production of hydrogen from the aqueous solution of NaBH4 in a small scale packed bed reaction column. The hydrogen generated from the catalytic decomposition of NaBH4 was accompanied by limited quantity of water vapour and alkaline mist. Nonetheless, higher quantities were generated when applying the acidic decomposition of NaBH4 and consequently the utilization of LNCT for H2 purification has proved useful and lead to a reduction in the content of these impurities; thereby the concentration of hydrogen in the outlet stream has increased.
文摘A combination of sodium borohydride and a catalytic amount of indium（Ⅲ） chloride in acetonitrile reduces imines formed in-situ from aldehydes and amines to the corresponding functionalised secondary and tertiary amines in moderate to good yields. Noteworthy is that highly chemoselective reactions were achieved in the presence of other functional groups such as halogens, carbon-carbon double bonds and hydroxyl groups.
基金supported by National Natural Science Foundation of China(22276144).
文摘Carbon nanotubes(CNTs)supported CoB and CoBSn catalysts were synthesized for hydrogen production via NaBH4 hydrolysis.The roles of Sn-promoter and the effect of CNTs treatment on CoB catalysts were evaluated and discussed.It is found that after the addition of Sn promoter,the specific surface area and the generation of active CoB phase are increased,while the oxidation treatment of CNTs results in more loading amounts of active components and enrichment of electron at active sites as well as large surface area.Consequently,the Sn-doped CoB catalysts supported on CNTs with oxidation treatment exhibits a significantly improved activity with a high H_(2)generation rate of 2640 mL/(min·g).Meanwhile,this catalyst shows a low activation energy of 43.7 kJ/mol and relatively high reusability.
