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
Nanocrystalline molybdenum carbide (Mo2C) was prepared via one simple route by the reaction of metallic magnesium powders with molybdenum trioxide and potassium acetate in an autoclave at the condition of 600℃ and 4 ...Nanocrystalline molybdenum carbide (Mo2C) was prepared via one simple route by the reaction of metallic magnesium powders with molybdenum trioxide and potassium acetate in an autoclave at the condition of 600℃ and 4 h. X-ray powder diffraction (XRD) pattern indicated that the product was hexagonal α-Mo2C, and the cell constant was a = 3.0091 ?, c = 4.7368 ?. Scanning electron microscopy (SEM) image showed that the sample consisted of particles with an average size of about 100 nm in diameter. The product was also studied by the thermogravimetric analysis (TGA). It had good thermal stability and oxidation resistance below 450℃ in air.展开更多
气候变化是人类社会在21世纪面临的最严峻挑战之一.由于气候变化导致的地表平均温度升高、降水规律改变,以及极端事件发生频率和强度增加,正在严重威胁人类的生命与健康.1988年由世界气象组织和联合国环境规划署资助成立政府间气候变化...气候变化是人类社会在21世纪面临的最严峻挑战之一.由于气候变化导致的地表平均温度升高、降水规律改变,以及极端事件发生频率和强度增加,正在严重威胁人类的生命与健康.1988年由世界气象组织和联合国环境规划署资助成立政府间气候变化专门委员会(IntergovernmentalPanel on Climate Change, IPCC),旨在科学地评估气候变化及其对人类和自然系统的潜在影响,并提出有效的减排和适应方案以管理气候变化带来的风险.展开更多
基金financially supported by National Key R&D Program of China(No.2018YFB1502101)the International/Hongkong,Macao&Taiwan Scientific and Technological Innovation Cooperation Project(2019YFH0148)。
文摘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.
文摘Nanocrystalline molybdenum carbide (Mo2C) was prepared via one simple route by the reaction of metallic magnesium powders with molybdenum trioxide and potassium acetate in an autoclave at the condition of 600℃ and 4 h. X-ray powder diffraction (XRD) pattern indicated that the product was hexagonal α-Mo2C, and the cell constant was a = 3.0091 ?, c = 4.7368 ?. Scanning electron microscopy (SEM) image showed that the sample consisted of particles with an average size of about 100 nm in diameter. The product was also studied by the thermogravimetric analysis (TGA). It had good thermal stability and oxidation resistance below 450℃ in air.
文摘气候变化是人类社会在21世纪面临的最严峻挑战之一.由于气候变化导致的地表平均温度升高、降水规律改变,以及极端事件发生频率和强度增加,正在严重威胁人类的生命与健康.1988年由世界气象组织和联合国环境规划署资助成立政府间气候变化专门委员会(IntergovernmentalPanel on Climate Change, IPCC),旨在科学地评估气候变化及其对人类和自然系统的潜在影响,并提出有效的减排和适应方案以管理气候变化带来的风险.
