CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Hefei Wang,Yongsheng Zhao,Tianyi Li,Zhen Chen,Yinan Wang,Chuanyu Qin
Calcium peroxide (CaO 2 ), as one of the solid peroxides, has been increasingly used in contaminated site remediation due to its ability to release oxygen (O 2 ) and hydrogen peroxide (H 2 O 2 ). Biodegradation can be enhanced by the existence of O 2 . Hydrogen peroxide can be used to for in situ chemical oxidation via the modified Fenton . Previous studies show inconsistent results about O 2 and H 2 O 2 release during CaO 2 decomposition. Additionally, the release characteristics of O 2 and H 2 O 2 are not evaluated in detail. A series of batch experiments was conducted to investigate the properties of CaO 2 decomposition and the release kinetics of O 2 and H 2 O 2 . O 2 and H 2 O 2 were released directly from CaO 2 dissolution and H 2 O 2 was not an essential intermediate in the conversion of CaO 2 to O 2 . The two release paths formed a parallel reaction system, with a competitive relationship between the two paths. The release of H 2 O 2 and O 2 followed a pseudo-zero-order kinetics pattern and a pseudo-first-order kinetics pattern, respectively. Increasing temperature and decreasing pH could accelerate both O 2 and H 2 O 2 release rate. However, increasing temperature could decrease the H 2 O 2 yield and increase the O 2 yield, which were similar to the impact of increasing pH.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
RSC Advances
·
2013
·Vol. 4
·期 5
·2550-2556
·
IF 2.562
Liuting Zhang,Xuezhang Xiao,Xiulin Fan,Shouquan Li,Hongwei Ge,Qidong Wang,Lixin Chen
A simple approach to dramatically enhance the dehydrogenation properties of sodium borohydride is achieved by ball milling NaBH4 with fluorographite (FGi). It was found that the ball-milled NaBH4–FGi composite starts to release hydrogen without impurity gas at a lower temperature of 125 °C, and obtains a hydrogen desorption capacity of ca. 4.8 wt% below 130 °C in seconds, which is improved markedly compared to the ball-milled pristine NaBH4. The significant thermodynamic and kinetic improvement of the NaBH4–FGi composite can be ascribed to the reaction between NaBH4 and FGi as well as the formation of micro-scale NaBH4. Moreover, since the dehydrogenation process of NaBH4–FGi composite is exothermal, the fully reverse reaction is not feasible. In-depth investigations show that the partial rehydrogenation is due to the formation of Na2B12H12 and another new borohydride.
研究领域:
材料科学
·
能源化学
·
纳米科技
·
物理化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Chengguo Yan,Jiaguang Zheng,Ao Xia,Qingbo Zhang,Meiling Lv,Zhenxuan Ma,Chao Su,Zhendong Yao
Among conventional hydrogen storage materials , LiBH 4 has been regarded as one of the best hydrogen transporters due to its relatively large hydrogen capacities. However, because of its extraordinarily high dehydrogenation temperatures, LiBH 4 was not suitable for hydrogen storage due to its stable thermodynamic features. Herein, we present a novel approach to LiBH 4 that uses solid-state multi-hydroxyl mannitol as a reactant, regulating hydrogen release below 69.9 °C. More than 7 wt% H 2 could be released with ultra-fast rates at 140 °C from the LiBH 4 -mannitol composite. XRD , FTIR , and SEM tests revealed that the reaction between mannitol (H δ+ ) and LiBH 4 (H δ− ) to produce hydrogen was accompanied by the generation of large amounts of heat in situ, which further promoted the decomposition of LiBH 4 for hydrogen production , exceeding the theoretical dehydrogenation amount of H δ+ - H δ− reaction. This work indicates possibilities for the development of fast and easy high-capacity hydrogen generation systems based on complex hydrides.
研究领域:
材料科学
·
无机化学
·
能源化学
·
氢能源存储
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Ying Xu,Kang Xue,Minhua Ai,Zehao Han,Chengxiang Shi,Ruijie Gao,Xiangwen Zhang,Ji-Jun Zou,Lun Pan
Dehydrogenation reaction occurs for the hydrogen release process of liquid organic hydrogen carriers (LOHCs), the regenerative cooling of advanced aircraft, etc. But the synergistic effects of Pt active sites are still ambiguous. Herein, a series of Pt-based catalysts with tunable Pt 0 -Pt δ+ sites were fabricated by changing the ratio of highly dispersed defected TiO 2 on MCM-41 (M41) for efficient dehydrogenation of methylcyclohexane (MCH). The characterizations indicate TiO 2 nanoparticles (NPs) are highly dispersed on M41 support, and possess abundant Ti 3+ /oxygen vacancies. The increase of TiO 2 loading amount can enhance the interaction between Pt NPs and TiO 2 , which increases Pt δ+ /Pt 0 ratio gradually. The dehydrogenation test and theoretical results confirm that the synergistic effect of Pt 0 and Pt δ+ sites contributes the optimal dehydrogenation performance, in which Pt 0 promotes the consecutive C–H bond cleavage and Pt δ+ significantly decreases the desorption energy barrier for H 2 and toluene (TOL). Specifically, the MCH conversion (when applied for LOHCs) is ca. 88 % and the selectivity of TOL is over 99.5 % under 1.0Pt/0.5TiO 2 /M41, while the high MCH conversion of 90 % and TOL selectivity of more than 86 % are achieved under 1.0Pt/1.0TiO 2 /M41 (as regenerative cooling for hypersonic vehicle). This work provides the approach of modulating the synergistic active sites to obtain high-performance dehydrogenation catalyst.
研究领域:
催化化学
·
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Chunmin Zhang,Chunli Wang,Qingyun Shi,Xiaoli Wang,Shaolei Zhao,Long Liang,Qingshuang Wang,Limin Wang,Yong Cheng
The high hydrogen release temperature and thermodynamic stability of the coordination hydride LiAlH 4 render it unsuitable for direct application. This work intends to improve the hydrogen release properties via compositing LiAlH 4 and AlH 3 with similar initial hydrogen release temperatures and introduce efficient additive Ni/CeO 2 composite. The thermal stability of the composite system LiAlH 4 -AlH 3 is enormously reduced compared to that of LiAlH 4 . In addition, the preferential release of hydrogen from LiAlH 4 in the composite system provides additional heat for the subsequent release of hydrogen from AlH 3 , accelerating the hydrogen release process. As a result, LiAlH 4 -AlH 3 -Ni/CeO 2 composite performs enhanced hydrogen release performance with a hydrogen release capacity of 8.27 wt% hydrogen within 300 ℃ and a dehydrogenation onset temperature as low as 72.9 ℃. The enthalpy change of the first step hydrogen release reaction decreases from −11.99 kJ mol −1 (LiAlH 4 ) to −2.02 kJ mol −1 (LiAlH 4 -AlH 3 ). Theoretical calculations indicate that both atomic dehybridisation and electron redistribution expedite the breaking of the Al-H bond and the consequent release of hydrogen.
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
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2011
·Vol. 36
·期 14
·8203-8208
·
IF 4.057
Z.G. Zhang,H. Wang,M. Zhu
The major challenge of complex hydride for hydrogen storage is to release hydrogen at a moderate temperature with rapid kinetics. This paper reports a new composite system (NaBH 4 /ZnF 2 ) to generate hydrogen at a low temperature below 100 °C. The NaBH 4 and ZnF 2 mixture was prepared by a mechanical milling in a 2:1 M ratio. Dehydrogenation of the mixture during a heating process shows that the initial dehydrogenation temperature was below 100 °C with favorable kinetics. The structural analysis confirmed the formation of NaBF 4 and Zn in the reaction products. The study concerning the reaction mechanism reveals that ZnF 2 plays a role of reagent rather than catalyst. The produced intermediate of NaZnF 3 , however, affects the decomposition of the emitted B 2 H 6 . This work suggests that the extension of the decomposition mechanism of NaBH 4 /ZnF 2 composite system would favor the development of new catalysts for complex hydride systems.
研究领域:
材料科学
·
能源化学
·
无机化学
·
储氢技术
·
纳米催化
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Zhe Zhang,Yusan Turap,Yongkang Wang,Yidi Wang,Zhentong Wang,Wei Wang
Thermochemical hydrogen storage technology based on iron-based materials has received significant attention owing to its low cost, safety features, and high volumetric hydrogen storage density. However, no consensus has been established on the optimal temperature range for hydrogen storage. This study investigated the impact of hydrogen storage temperature on hydrogen consumption capacity, hydrogen release capacity, and hydrogen storage energy consumption. The hydrogen storage temperature was optimized with the objectives of low energy consumption and high hydrogen storage density. The experiments were conducted using thermogravimetric analyzer and gram-scale packed-bed reactor setups, accompanied by thermodynamic and kinetic calculations. The research indicated that at 550 °C, the optimal hydrogen storage temperature, the lowest relative energy demand was 32.30 %, with the hydrogen consumption capacity reaching the theoretical maximum value of 4.8 %, and the hydrogen release capacity reaching 4.04 %. Furthermore, achieving the theoretical maximum value of hydrogen consumption capacity became exceedingly difficult when the hydrogen storage temperature exceeded 570 °C. Microstructural characterization and kinetic calculations revealed that this phenomenon was attributed to the formation of a dense iron layer on the particle surface, which impeded the solid-state diffusion of oxygen atoms. The formation of the intermediate phase wüstite was identified as the cause of the formation of the dense iron layer. Overall, this study provided theoretical support for iron-based thermochemical hydrogen storage processes and offered a perspective into the reaction behavior of the reduction of magnetite with hydrogen.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Haiqiang Bai,Biao Liu,Ling Kang,Yanhong Wang,Jing Bai,Santosh Kumar Verma,Yunhua Xu
The ability of magnesium-based hydrogen storage materials to store and release hydrogen is hampered by their relatively slow rates. To address this, Mg-x% Co (x = 5, 10, 15) magnesium-rich hydrogen storage alloys were fabricated using reactive ball milling. The resulting alloys were multiphase, composed of Mg, Co, MgCo₂, and Mg₂CoH₅, which provided nucleation sites and improved hydrogen uptake. The reduced particle size and surface microcracks and pores enhanced hydrogen diffusion. The Mg-15 %Co alloy had the ability to take in 4.72 wt% hydrogen in 1 min when the temperature was set at 350°C. Hydrogenation resulted in the formation of a biphasic structure composed of Mg₂CoH₅ and Mg₆Co₂H₁₁. This structure destabilized the Mg-H bond and improved the kinetics of hydrogen release. The hydrogen release capacity first increased and then decreased with Co content, with Mg-10 %Co showing the best performance. Due to the combined action of ball milling and Co catalysis, the Mg-10 %Co alloy had an activation energy for hydrogen release of 113.65 kJ/mol, making it the alloy with the lowest such activation energy in the set. Differential scanning calorimetry (DSC) analysis confirms that cobalt addition reduces the hydrogen release peak temperature of Mg by 16.58–29.67 °C, with the Mg-10 % Co alloy exhibiting peak temperatures of 410.72–425.53 °C, attributed to synergistic decomposition of MgH₂ with intermediate hydrides like Mg₂CoH₅ and Mg₆Co₂H₁₁. The findings of this study indicate that alloying Mg-based alloys with transition elements while performing ball milling is a practical method for enhancing their hydrogen storage and release kinetics.
研究领域:
材料科学
·
能源存储
·
纳米技术
·
合金工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2023
·
IF 6.4
Na Yang,Huchen Yao,Fanqi Bu,Mengyue Gu,Xuewen Zhao,Lei Huang,Chonghan Zhao,Yonghong Cheng,Jinying Zhang
Hydrolysis of LiAlH4 is a promising path to supply hydrogen at low temperatures due to its high hydrogen storage capacity, where an anti-icing aqueous solution is necessary. However, no hydrolysis kinetics of LiAlH4 with an anti-icing aqueous solution has been reported due to its complexity. Herein, an optimized anti-icing aqueous solution with 27.1 wt% KOH and 30.0% ethylene glycol has been found to obtain full and controllable hydrolysis kinetics of LiAlH4 at −40 to 0 °C. The effects of compactness, mass, and temperature on the hydrolysis of LiAlH4 have been investigated. The LiAlH4 tablet with compactness of 92.7% was demonstrated to obtain a wide constant reaction region (>95%) and be suitable for the hydrolysis reactions. The hydrogen release rates at constant reaction regions were found to follow a linear relationship with the 0.42 power of the mass of a compacted LiAlH4 tablet. A strong temperature-dependent hydrolysis was observed, where the activation energy was deduced from experimental data to be 6.83 ± 0.34 kJ·mol–1. The hydrolysis products of LiAlH4 with the adopted anti-icing aqueous solution after washing with deionized water were found to be the same as those directly with water, indicating no consumption of KOH and ethylene glycol in the reactions. The hydrolysis reaction of LiAlH4 with the adopted solution at −40 to 0 °C has been demonstrated to follow the shrinking core model controlled by liquid film diffusion.
研究领域:
无机化学
·
能源材料
·
催化化学
·
氢能源存储
·
反应动力学
✓ 已验证
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2015
·
IF 5.636
Zhenzhen Li,Yanmei Xin,Zhonghai Zhang
In this work, we clearly demonstrate for the first time the use of a p-type semiconductor, Cu2O, as the core unit of a photocathode to set up a new photocathodic analysis platform. With the help of a facile protection strategy, the Cu2O photocathode presented efficient photoelectrochemical performance for H2O2 sensing with a detection limit of 0.15 μM, which allowed the new photocathodic analysis platform to detect H2O2 released from living tumorigenic cells, thus demonstrating its potential application as a sensitive cancer detection probe. The protected TiO2 layer was coated on Cu2O to form a quasi-core/shell structure (TiO2@Cu2O) through a facile sol–gel method, which significantly enhanced the photostability, comparable to the TiO2@Cu2O samples prepared by a complicated atomic layer deposition method. In this new photocathodic analysis platform, the semiconductive metal oxides accomplish a job usually completed by conductive noble metals in an electroanalysis process. We believe that this photocathodic detection strategy opens up a new detection approach, extends the application range of semiconductor materials, and thus sheds light on the further fusing of photoelectrochemical technique with analytical methods.
研究领域:
分析化学
·
光电化学
·
生物医学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Physical Chemistry Letters
·
2024
·
IF 4.8
Zibo Cheng,Yeqin Guan,Hong Wen,Zhao Li,Kaixun Cui,Qijun Pei,Shangshang Wang,Claudio Pistidda,Jianping Guo,Hujun Cao,Ping Chen
Lithium hydride (LiH), a saline hydride with a hydrogen density of 12.6 wt %, is highly thermostable, which hinders its extensive application in hydrogen storage. In this study, we demonstrate a distinct photodecomposition of LiH under ambient conditions. Ultraviolet–visible (UV–vis) illumination induces hydrogen release and creates surface hydrogen vacancies on LiH. The subsequent H– migration enables hydrogen desorption and the accumulation of vacancies at the subsurface, resulting in the generation of metallic Li clusters. Rehydrogenation, on the contrary, can be charged under UV–vis illumination in 1 bar H2. Such phenomena show that the thermodynamic and kinetic limits in the re/dehydrogenation of LiH can be broken under illumination, which allows hydrogen storage over the LiH surface at temperatures ∼600 K lower than those of the corresponding thermal process. This work provides new insights into the interaction of semiconducting hydrides and photons and opens an avenue for the development and optimization of materials for hydrogen storage and related photodriven reactions.
研究领域:
储氢
·
材料科学
·
表面化学
·
光化学
·
半导体氢化物
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）