ELECTROCHIMICA ACTA
·
2014
·
IF 4.086
Zhenhua Yan,Min Wang,Jifeng Liu,Renmin Liu,Jinsheng Zhao
Insufficient catalytic activity and durability are the most challenging issues in the commercial deployment of low-temperature fuel cells. In an effort to address these barriers, three carbon-supported Pt x Fe alloy electrocatalysts with varying Pt:Fe atom ratios (Pt 3 -Fe/C, Pt 2 -Fe/C, Pt-Fe/C) were prepared by simple NaBH 4 reduction in glycerol at room temperature. All of the prepared Pt x Fe nanoparticles (NPs) are highly dispersed on a carbon support and show a single-phase face-centered cubic structure with a particle size of approximately 2 nm. The electrocatalytic performances of the synthesized Pt x Fe alloy catalysts were compared with that of commercial Pt/C by cyclic voltammetry and linear sweep voltammetry; among these NPs, the Pt 3 -Fe/C catalyst exhibits the highest activity and the best stability for oxygen reduction reaction (ORR) in both acidic and neutral media. As the cathode catalyst, the maximum power density produced from microbial fuel cell with Pt 3 -Fe/C (1680 ± 15 mW m −2 ) was 18% higher than that with conventional Pt/C (1422 ± 18 mW m −2 ), and the stability of Pt 3 -Fe/C was greatly improved.
研究领域:
材料科学
·
电化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2021
·
IF 2.495
Minmin Liu,Baitong Niu,Hongxu Guo,Shaoming Ying,Zhangxu Chen
g-C 3 N 4 @Ni 3 C nano-sheets have been prepared by a simple pyrolysis under different temperature, and the as-prepared samples have been characterized by many means, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), the Brunauer–Emmett–Teller (BET) and pore size distribution. The as-prepared g-C 3 N 4 @Ni 3 C nano-sheet has been proved to be a versatile functional material, that is the application in supercapacitor electrode materials, hydrogen generation via NaBH 4 hydrolysis and reduction of p– nitrophenol. This method offers a new strategy for preparation of environmental energy materials through simple raw materials.
研究领域:
材料科学
·
能源化学
·
催化化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Ran Li,Hao Shi,Jinlin Song,Zihong Dong,Tao Wan,Hua Dong
The introduction of magnetism into a catalyst can greatly optimize its separation performance. In the present work, a kind of magnetically separable catalysts for promoting NaBH 4 hydrolysis have been fabricated by anchoring cobalt nanoparticles on magnetic dendritic KCC-1 nanospheres composed of magnetic Fe 3 O 4 core and fibrous shell. The fabricated catalysts were characterized with various characterization methods, including absorption spectroscopy (AAS), scanning electron microscopy (SEM), high-resolution transmission electronic microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometry (VSM), and Fourier transform infrared (FT-IR), etc. This kind of catalysts exhibit high catalytic activity for promoting the hydrolysis of NaBH 4 under alkaline conditions, giving a hydrogen generation rate and activation energy of 3.83 L min −1 g Co −1 (30 °C) and 53.63 kJ mol −1 , respectively. After used for 5 cycles, the catalyst showed 36.5% catalytic activity reserved. Most importantly, the magnetism of the catalyst made it easily separated and recycled from the solution after the reaction completed. The development of this kind of catalysts could provide a promising option for catalyzing NaBH 4 hydrolysis for portable hydrogen production from.
研究领域:
催化
·
纳米技术
·
氢能
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Tianping Huang,Jianxin Zou,Ning Zhao,Xiaoqin Zeng,Wenjiang Ding
A new reversible hydrogen storage system, 3NaBH 4 -0.5ScF 3 -0.5YF 3 , was synthesized by using the ball-milling method. It is shown that no reaction occurs during the ball-milling process. The hydrogen desorption process of the ball-milled composite can be divided into three consecutive steps: (i) An initial stage from room temperature to 320 °C with about 0.42 wt% of hydrogen released, that can be ascribed to the substitution of H − by F − in NaBH 4 ; (ii) The second stage starts from 320 °C to 450 °C, releasing about 1.06 wt% of hydrogen; (iii) The final stage ranges from 450 °C to 480 °C, with 2.58 wt% of hydrogen released. The total yield of hydrogen reaches 4.06 wt% at 480 °C. The completely dehydrogenated products of the 3NaBH 4 -0.5ScF 3 -0.5YF 3 composite can absorb 2.15 wt% of hydrogen at 380 °C in 6.5 h, which shows greatly enhanced reversibility when compared with sole ScF 3 addition. It should be noted that one of the destabilizers ScF 3 was also regenerated besides NaBH 4 in the rehydrogenated products. Based on the XRD and FTIR analyses, the synergistic effects of 3d transition metal fluoride ScF 3 and rare earth metal fluoride YF 3 on the hydrogen desorption and absorption performance of NaBH 4 were discussed.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2014
·
IF 2.93
Lina Chong,Jianxin Zou,Xiaoqin Zeng,Wenjiang Ding
In this work, the complex hydrogen sorption behaviors in a 3NaBH 4 /HoF 3 composite prepared through mechanical milling were carefully investigated, including the reactions occurred during ball milling and de-/rehydrogenation processes. Different from other rear earth fluorides, the HoF 3 can react with NaBH 4 during ball milling, leading to the formations of Na–Ho–F and Na–Ho–BH 4 complex compounds. The first dehydriding of the 3NaBH 4 /HoF 3 composite can be divided into 4 steps, including the ion exchange between H − and F − , the formation of NaHo(BH 4 ) 4 , the decomposition of NaHo(BH 4 ) 4 and reaction of NaBH 4 with Na–Ho–F compounds. The final products, HoB 4 , HoH 3 and NaF, can be rehydrogenated to generate NaBH 4 and NaHoF 4 with an absorption capacity of 2.3 wt% obtained at 400 °C. Based on the Pressure–Composition–Temperature measurements, the de-/rehydrogenation enthalpies of the 3NaBH 4 /HoF 3 composite are determined to be 88.3 kJ mol −1 H 2 and −27.1 kJ mol −1 H 2 , respectively.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2019
·Vol. 11
·期 13
·5998-6003
·
IF 6.97
Dongjun Shen,Yijuan Long,Jie Wang,Yuanyuan Yu,Jiangli Pi,Lili Yang,Huzhi Zheng
A reduction pathway was developed to tune the fluorescence quantum yield (QY) and emission wavelength of carbon dots (CDs). Reducing the original CDs (QY ca. 1.55%, maximum emission ca. 520 nm) with NaBH4 increased QY to 7.25% and blue-shifted the maximum emission to 450 nm. Treating the original CDs with LiAlH4 increased QY to ca. 7.44% and blue-shifted the maximum emission to 345 nm. The distinct fluorescence characteristics of the original CDs, NaBH4-treated CDs, and LiAlH4-treated CDs were conferred by their differing surface groups. Moreover, the original CDs, NaBH4-treated CDs, and LiAlH4-treated CDs responded differently to a specific oxidizer of hydroxyl groups. The increase in the fluorescence QY and blue-shift of the emission wavelength were explained. This study provides a foundation for the preparation and tuning of CDs with excellent fluorescence performance, as well as for the development CD-based fluorescent probes.
研究领域:
材料科学
·
光学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2013
·Vol. 1
·期 43
·13510-13523
·
IF 0
Lina Chong,Jianxin Zou,Xiaoqin Zeng,Wenjiang Ding
In the present study, a new hydrogen storage system, being able to reversibly absorb/desorb hydrogen at fairly low temperatures, was developed based on a 3NaBH4–PrF3 composite. It is shown that 3 wt% of reversible hydrogen sorption can be achieved in the 3NaBH4–PrF3 composite at 400 °C with fast kinetics. After the addition of 5 mol% VF3, the dehydrogenation kinetics of the 3NaBH4–PrF3 composite can be significantly improved. The onset dehydriding temperature is lowered down to 46 °C in vacuum, and the dehydrogenation finishes in 2 min at 400 °C. Both the dehydrogenation enthalpy and activation energy of 3NaBH4–PrF3 can be lowered down through the addition of VF3. In particular, the dehydrogenation products of the 3NaBH4–PrF3–5 mol% VF3 composite can be rehydrogenated at a temperature as low as 48 °C with the regeneration of NaBH4. At 84 °C, a reversible hydrogen sorption of about 1.2 wt% can be achieved in the 3NaBH4–PrF3–5 mol% VF3 composite. The improvement in hydrogen sorption properties can be mainly attributed to the formation of the VB2 phase during dehydrogenation as an efficient catalyst, which maintains well its catalytic effect in the re-/dehydrogenation cycles. Based on a series of controlled experiments and phase analyses, the de-/rehydrogenation mechanisms of the 3NaBH4–PrF3 composite without and with VF3 addition are proposed and discussed in detail.
研究领域:
材料科学
·
氢能
·
固态化学
✓ 已验证
DOI
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Hao Zhong,Kang Chen,Chenglei Qin,Chengguang Lang,Jiangwen Liu,Hui Wang,Junrui Zhang,Liuzhang Ouyang
Onsite hydrogen generation by sodium borohydride hydrolysis resolves hydrogen energy supply system challenges. However, the spent-NaBH 4 regeneration is still a problem in the closed loop of this irreversible reaction. As the by-product is the key to the problem, NaB(OH) 4 is regarded as not the boron source but the hydrogen source of NaBH 4 regeneration. Therefore, in this study, inexpensive Al metal and NaB(OH) 4 are ball milled under argon to regenerate NaBH 4 without additional hydrogen input. However, the ball-milling reaction is hindered by the flexible Al and impact oxide layer, and the NaBH 4 yield is only approximately 22 %. Therefore, a brittle intermetallic compound Mg 2 Al 3 is reacted with NaB(OH) 4 by ball milling, achieving a NaBH 4 yield of over 42 %. The mechanism study shows that the brittleness of the raw material plays an important role in promoting the ball-milling reaction. This study achieves NaBH 4 regeneration using only Al as the reducing agent and provides a promising method to promote the mechanochemical regeneration of NaBH 4 .
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Tianping Huang,Jianxin Zou,Huabing Liu,Wenjiang Ding
Three kinds of transition metal fluorides TMF x (TM = Nb, Co, Ti) were introduced into the 3NaBH 4 -GdF 3 hydrogen storage system via mechanical milling. Their effects on the hydrogen storage behaviors of 3NaBH 4 -GdF 3 were systematically investigated by means of DSC and volumetric methods. All TMF x exhibited promoting effect on hydrogen desorption properties of 3NaBH 4 -GdF 3 to different degrees, especially when NbF 5 or TiF 3 was added. For example, the hydrogen desorption peak temperature was decreased by 17 °C with doping 3 mol% of NbF 5 . Besides, TiF 3 improved also the hydrogen absorption capacity and reversibility of 3NaBH 4 -GdF 3 . Based on XRD analyses, the role of TMF x on the dehydrogenation and the promoting effect of TiF 3 on the reversibility of 3NaBH 4 -GdF 3 were clarified. This work helped to understand the combination effect of rare earth metal fluoride (GdF 3 ) and transition metal fluorides on the reversible hydrogen storage properties of NaBH 4 .
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 18
·10932-10938
·
IF 3.119
Yunfei Chang,Mingyi Liao,Xueyan Li
Using a simple one-pot method, the reduction of liquid terminated-carboxyl fluoroelastomers (LTCFs) by sodium borohydride and samarium chloride (NaBH4/SmCl3) was successfully realized and liquid terminated-hydroxyl fluoroelastomers (LTHFs) were obtained. The structure and functional group content of LTCFs and LTHFs were analyzed by FTIR, 1H-NMR, 19F-NMR and chemical titration. The results showed that –CC– and carboxyl groups of LTCFs were reduced efficiently, the reduction rate reached 92% under optimum reaction conditions. Compared with other frequently-used metal chlorides, SmCl3 with a high coordination number could increase the reduction activity of NaBH4 more effectively and the reduction mechanism was explored.
研究领域:
材料化学
·
有机化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Xiaoqing Cao,Jun Zhou,Zhipeng Zhai,Song Li,Guo Yuan,Gaowu Qin
Development of efficient and sustainable monolithic catalysts for NaBH4 hydrolysis remains an important goal for hydrogen cycling. In this work, the structured catalyst Ru/MgO with an on–off feature has been prepared by directly growing a nano-Ru-embedded MgO coating layer on a Mg substrate via an instant high-temperature plasma oxidation process. The porous MgO framework provides an ideal space for the access of reactants and diffusion of mass transport, which facilitates reaction triggering and the expulsion of byproducts to avoid poisoning the catalyst. Importantly, Ru nanoparticles (NPs) are monodisperse with ultrasmall particle size deriving from a concurrent rapid arcing and fast quenching. The hierarchical structured Ru NP catalysts are highly active for hydrolysis of sodium borohydride by achieving a high hydrogen generation rate (HGR) of 101,189 mL min–1 g–1 and exhibit attractive stability. In addition, it is facile to realize the “on–off” functionality based on simple separation that could accurately control the hydrogen generation, suggesting the structured catalyst to be of great potential for practical applications. This simple method opens valuable opportunities for fast synthesis of the high-quality structured catalyst and could be extended to various noble metals on oxides of valve metals with high catalytic performance.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of CO2 Utilization
·
2023
·
IF 7.7
Shibo Yuan,Peng Bai,Yi He,Jiafa Chen,Yicheng Zhao,Yongdan Li
Photocatalytic N-formylation of amines with CO 2 is a promising strategy to convert CO 2 into value-added chemicals sustainably. In this work, a black TiO 2 -supported Cu photocatalyst is prepared through a solvothermal method for the N-formylation of N-methylaniline with NaBH 4 as the reducing agent. Cu nanoparticles and oxygen vacancies are formed on the surface of the photocatalyst after reduction with H 2 , which decreases the band-gap energy and promotes the separation of photogenerated electrons and holes, thereby improving the photocatalytic activity remarkably. A 100 % conversion is achieved after 9 h radiation, and the yield of N -methylformanilide reaches 81 %. Both the amount of NaBH 4 and the pressure of CO 2 show important influences on the activity and selectivity of the photocatalytic process, and the carbon and hydrogen in the aldehyde group are from CO 2 and NaBH 4 , respectively. The photocatalyst also shows promising cycling durability.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）