CHEMICAL ENGINEERING JOURNAL
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2015
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IF 4.321
Chen Sun,Zimo Lou,Yu Liu,Ruiqi Fu,Xiaoxin Zhou,Zhen Zhang,Shams Ali Baig,Xinhua Xu
In this study, nanosized titanium nitride (nTiN) doped palladium/nickel (Pd/Ni) foam electrodes were prepared via electroless deposition method for the dechlorination of 2,4-dichlorophenoxyacetic acid (2,4-D). Characterization analyses including field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM) revealed that nTiN was successfully doped onto the electrode surface. 2,4-D was first dechlorinated to intermediate products p -chlorophenoxyacetic acid ( p -CPA) or o -chlorophenoxyacetic acid ( o -CPA) and then to the final product, phenoxyacetic acid (PA). The effects of environmental factors including initial 2,4-D concentration, current density, reaction temperature and dissolved anions were also studied. High initial 2,4-D concentration increased the efficient utilization of active hydrogen atom [H] by nTiN doped Pd/Ni foam electrodes. Increases in current density promoted better dechlorination efficiency while the hydrogen evolution side reaction was undesirably increased, leading to a lower average current efficiency. Higher reaction temperature was proved to be favorable for the enhancement of dechlorination efficiency. NO 3 − and reduced sulfur compounds including S 2− and SO 3 2− showed negative impacts on Pd catalytic capability, whereas CO 3 2− and Cl − exhibited less adverse effects on dechlorination efficiency. The activation energy ( E a) value of 2,4-D dechlorination by nTiN doped Pd/Ni foam electrode was calculated to be 32.06 kJ mol −1 . Two typical stages namely electrode activation and efficient dechlorination procedures occurred in 2,4-D dechlorination by nTiN doped Pd/Ni foam electrodes. The reaction paths of [H] on the electrode were also summarized. The removal efficiency of 2,4-D dechlorination on nTiN doped Pd/Ni foam electrodes was observed to slightly decrease from 100% to 89.95% after 5 consecutive experiments.
研究领域:
环境科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
Energetic Materials Frontiers
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2025
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IF 3.9
Su-hang Chen,Jie Zhang,Kui Tang,Xi Chen,Jia Zhao,Tuan Zhao,Bin Zhang,Kang-zhen Xu
Microwave ignition (MWI) technology enables synchronized large-area multi-point ignition, multi-pulse operation, higher combustion temperature and efficiency, and dynamic thrust modulation through microwave field adjustments compared to conventional electric ignition methods. However, MWI application is still limited by the absence of a microwave-responsive ignition agent. Herein, A series of nano-titanium/copper ferrite/potassium perchlorate ( n- Ti-CFO/KP (0∼40%)) microwave-sensitive agents were successfully synthesized via electrostatic spraying, where KP enhances combustion, while CFO acts as both catalyst and microwave sensitizer. MWI results demonstrate that n- Ti-CFO/KP (10%) exhibits the shortest ignition delay time (IDT) by 6.34 ms, owing to its high chemical reactivity and the high microwave absorption of Ti, CFO. Combustion analysis suggests that n- Ti-CFO/KP (40%) composite achieves 10-fold combustion enhancement over KP-free ignition agents by a peak pressure of 552.2 kPa and combustion rate of 221.4 m·s -1 , while n- Ti-CFO/KP exhibits the combustion flame temperature of 1250 °C compared to n- Ti-CFO by 700 °C. This remarkable improvement is attributed to the synergistic catalytic activation and combustion - supporting effects of CFO. Furthermore, n- Ti-CFO/KP (10%) exhibits comparable combustion and sensitivity performance to conventional agents ( μ- Ti/KP and B/KNO 3 ). The n- Ti-CFO/KP (10%) shows its main exothermic peak at 310 °C, significantly lower than the 550 °C peak observed for μ- Ti/KP, as well as the excellent catalytic decomposition effect of CFO on KP was further confirmed, where the low reaction temperature can shorten the microwave dielectric heating time. The synergistic effect and combustion intensification result from the coupled interaction between the microwave thermal characteristics of n- Ti-CFO and low-temperature oxygen release kinetics of KP. This coupling achieves significantly reduced MWI delay and enhanced energy release rates, thereby overcoming traditional combustion's reliance on high-temperature conditions. This result provides a new insight into the design of pyrotechnics and propulsion for fast plasma generation and microwave combustion.
研究领域:
材料科学
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燃烧学
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能源化学
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推进技术
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功能材料
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物理化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2014
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IF 6.007
Chen Sun,Shams Ali Baig,Zimo Lou,Jin Zhu,Zhuoxing Wang,Xia Li,Jiahan Wu,Yifu Zhang,Xinhua Xu
Nanosized titanium nitride (nTiN) doped palladium/nickel (Pd/Ni) foam electrodes were successfully prepared via electroless deposition method. The electrodes were evaluated by different techniques including field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and linear sweep voltammetry (LSV). FE-SEM images demonstrated that two different morphologies existed in the Pd layer after nTiN doping. The nTiN doped Pd/Ni foam electrodes were found to be highly effective for electrochemical reductive dechlorination of 2,4-dichlorophenoxyacetic acid (2,4-D) with excellent activity and stability, as revealed by batch experiments. Under the conditions of nTiN doping content of 2 mg, Pd loading of 0.44 mg cm −2 , the energetic electrode achieved nearly 100% removal of 2,4-D (0.226 mmol L −1 ) within 2 h at a current density of 1.667 mA cm −2 . However, the removal efficiency reached only 57.13% when a normal Pd/Ni foam electrode with identical Pd loading and current density was utilized. A successive 2,4-D reductive dechlorination process was observed. o -Chlorophenoxyacetic acid ( o -CPA), p -chlorophenoxyacetic acid ( p -CPA) and phenoxyacetic acid (PA) were detected and identified as transformation products. Regression analysis proved that the pseudo-first order kinetic model was not suitable to describe the dechlorination process on nTiN doped Pd/Ni foam electrodes due to the appearance of a plateau in the beginning of the curve. Moreover, an adsorption theory for Pd chemisorption of active hydrogen atom was proposed to better explain the phenomenon. An adsorption equilibrium of hydrogen existed in the Pd lattice between hydrogen in Pd solid solution and hydrogen in metal hydride, which would influence the effective utilization of active hydrogen atom [H] for dechlorination treatment. An indirect reduction mechanism of the 2,4-D dechlorination on the as-prepared electrodes was also elucidated.
研究领域:
环境科学
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电化学
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污染控制
✓ 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）