CHINESE JOURNAL OF CATALYSIS
·
2025
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IF 17.7
Shaolei Gao,Peng Lu,Liang Qi,Yingli Wang,Hua Li,Mao Ye,Valentin Valtchev,Alexis T. Bell,Zhongmin Liu
Methyl methoxyacetate (MMAc) and methyl formate (MF) can be produced directly by heterogeneous zeolite-catalyzed carbonylation and disproportionation of dimethoxymethane (DMM), with near 100% selectivity for each process. Despite continuous research efforts, the insight into the reaction mechanism and kinetics theory are still in their nascent stage. In this study, ZEO-1 material, a zeolite with up to now the largest cages comprising 16×16-MRs, 16×12-MRs, and 12×12-MRs, was explored for DMM carbonylation and disproportionation reactions. The rate of MMAc formation based on accessible Brönsted acid sites is 2.5 times higher for ZEO-1 (Si/Al = 21) relative to the previously investigated FAU (Si/Al = 15), indicating the positive effect of spatial separation of active sites in ZEO-1 on catalytic activity. A higher MF formation rate is also observed over ZEO-1 with lower activation energy (79.94 vs. 95.19 kJ/mol) compared with FAU (Si/Al = 30). Two types of active sites are proposed within ZEO-1 zeolite: Site 1 located in large cages formed by 16×16-MRs and 16×12-MRs, which is active predominantly for MMAc formation, and Site 2 located in smaller cages for methyl formate/dimethyl ether formation. Kinetics investigation of DMM carbonylation over ZEO-1 exhibit a first-order dependence on CO partial pressure and a slightly inverse-order dependence on DMM partial pressure. The DMM disproportionation is nearly first-order dependence on DMM partial pressure, while it reveals a strongly inverse dependence with increasing CO partial pressure. Furthermore, ZEO-1 exhibits good catalytic stability, and almost no deactivation is observed during the more than 70 h test with high carbonylation selectivity of above 89%, due to the well-enhanced diffusion property demonstrated by intelligent-gravimetric analysis.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2023
·Vol. 33
·期 38
·2301913
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IF 19
Meng Liu,Guocheng Lv,Hao Liu,Yuqing Fu,Jian Zhang,Libing Liao,De-en Jiang,Juchen Guo
Herein, a self-charging mechanism of rechargeable aluminum (Al) batteries with Chevrel phase molybdenum sulfide (Mo 6 S 8 ) cathode is reported. The results unambiguously reveal that the self-charging is a spontaneous disproportionation of Al intercalated Mo 6 S 8 originated from the dynamic shift of Al between occupied sites during Al intercalating and resting. The theoretical study indicates that the fully Al intercalated Mo 6 S 8 in the format of Al 4/3 Mo 6 S 8 is kinetically accessible driven by electrochemical overpotential but thermodynamically unstable due to the repulsion between Al 3+ cations. This mechanism is a true self-charging with no input of any form of energy, thus distinctly superior to the previously reported self-charging mechanisms. Based on this discovery, a semi-flow Al Mo 6 S 8 battery is designed and demonstrated with long-lasting discharge capability and high capacity.
研究领域:
材料科学
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电化学
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能源存储
✓ 已验证
产品关联
DOI
高影响因子
Frontiers of Environmental Science & Engineering
·
2019
·Vol. 13
·期 2
·1-12
·
IF 3.883
Deng Yuzhou,Peng Shengpan,Liu Haidi,Li Shuangde,Chen Yunfa
Mesoporous TiO 2 was synthesized via nonhydrolytic template-mediated sol-gel route. Catalytic degradation performance upon dichloromethane over as-prepared mesoporous TiO 2 , pure anatase and rutile were investigated respectively. Disproportionation took place over as-made mesoporous TiO 2 and pure anatase under the presence of water. The mechanism of disproportionation was studied by in situ FTIR. The interaction between chloromethoxy species and bridge coordinated methylenes was the key step of disproportionation. Formate species and methoxy groups would be formed and further turned into carbon monoxide and methyl chloride. Anatase (001) played an important role for disproportionation in that water could be dissociated into surface hydroxyl groups on such structure. As a result, the consumed hydroxyl groups would be replenished. In addition, there was another competitive oxidation route governed by free hydroxyl radicals. In this route, chloromethoxy groups would be oxidized into formate species by hydroxyl radicals transfering from the surface of TiO 2 . The latter route would be more favorable at higher temperature.
研究领域:
催化化学
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材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Huizhen Lv,Yu Song,Zengming Qin,Mingyue Zhang,Duo Yang,Qing Pan,Zhihui Wang,Xinjian Mu,Jianming Meng,Xiaoqi Sun,Xiao-Xia Liu
The disproportionation of the Jahn-Teller (J-T) active manganese oxides (Mn 3+ ) often leads to uncontrollable Mn 2+ dissolution, which has been identified as one of the major causes of the performance degradation in conventional Zn-MnO 2 batteries. Herein, we use the “unwanted” disproportionation of the Mn 3+ cations to realize effective MnO 2 /Mn 2+ transformation, achieving high specific capacity (550 mAh g −1 ) and good cycling stability (5000 cycles without capacity decay) in a Zn-MnO 2 hybrid battery with mild aqueous electrolytes. Mechanism study shows that MnO 2 is deposited on the cathode during charging, H + /Zn 2+ insertion and disproportionation occur sequentially during discharging, leading to Mn 2+ dissolution. The generated high-valence manganese oxides via disproportionation further experience reduction-disproportionation-dissolution, which proceeds repeatedly in the expanded discharge potential to 0 V vs. Zn 2+ /Zn, resulting in the complete dissolution of the cathodic materials. Our results provide the fundamental understanding on the controversial mechanisms of Zn-MnO 2 batteries with mild aqueous electrolytes and highlight the effect of disproportionation in pushing the electrochemical performance of the promising Zn-MnO 2 hybrid batteries.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
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2016
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IF 2.101
Shunyu Han,Zheng Wang,Longyue Meng,Nanzhe Jiang
Mesoporous ZSM-5 zeolites were synthesized by using hydrophilic carbon black as a hard template. Hydrophobic carbon black was oxidized with sodium hypochlorite solution then dispersed into the synthetic precursor, and hydrothermally treated by omitting the evaporation process. The samples were characterized by SEM, TEM, XRD , nitrogen adsorption/desorption and NH 3 -TPD measurements. As a result, mesoporous ZSM-5 zeolites were obtained in the morphology of single crystal like aggregates (about ∼2 μm) with intra-mesopores in the range of 5–18 nm. Textural properties and acidity of mesoporous ZSM-5 zeolites were varied by adjusting the amount of carbon black used. In the toluene disproportionation, mesoporous ZSM-5 templated by hydrophilic carbon black showed more active in toluene conversion and more selective to the para -xylene than conventional zeolite, and even comparable to the commercial zeolite catalyst.
研究领域:
材料科学
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催化化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2020
·
IF 3.871
Yongwan Gu,Yunyan Li,Jiaoxia Zhang,Huiying Zhang,Chunhua Wu,Jing Lin,Juying Zhou,Yuhang Fan,Vignesh Murugadoss,Zhanhu Guo
Pd/C catalysts were prepared by an incipient-wetness impregnation and their catalytic performance in disproportionation of rosin was investigated. The texture structure, groups on the activated carbon surfaces, and acidity were characterized by N 2 physisorption-desorption, Fourier transform infrared spectroscopy (FTIR), and temperature-programmed desorption (TPD). The Pd/AC3 (treated at 443 K) had the highest Pd dispersion (23.60%) with the highest specific surface area of activated carbon (1057 m 2 /g). Nevertheless, the Pd/AC0 (original carbon black) had the lowest Pd dispersion (13.07%) with a lower specific surface area of original activated carbon (994 m 2 /g). Pd/AC3 presented a considerable catalytic activity in the rosin disproportionation reaction, with 64.15% dehydroabietic acid and without abietic acid in product. However, Pd/AC0 (Pd supported on the original carbon) showed a much lower catalytic activity in the rosin disproportionation reaction, with 42.64% dehydroabietic acid and 3.59% abietic acid in product.
研究领域:
化学工程
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2021
·
IF 3.605
Jing Li,Jianguang Guo,Qing Sun,Xiangkun Nie,Linna Dai,Yu Wang,Lijie Ci
Silicon monoxide (SiO) has captured great attention as one of the most promising anode materials due to its great cycling stability as well as high theoretical capacity. However, hindered by its low initial Coulombic efficiency, the possible large-scale application remains an urgent issue. Herein, through a facile method, potassium ions are introduced into the disproportionation process of SiO to promote the transition from amorphous SiOx into the cristobalite phase with higher crystallinity. The cristobalite phase exhibits lower reaction activity with lithium ions, which reduces the formation of lithium silicate. As a consequence, the cycling stability and the initial Coulombic efficiency (ICE) are improved. In addition, it is proved in our study that increasing the heating temperature is helpful to improve the ICE and cycling stability of SiO. This work provides a facile disproportionation method for the microstructure regulation of SiO, offering a possible avenue for the development of large-scale applications of the SiO anode.
研究领域:
材料科学
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电化学
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纳米材料
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能源存储
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固体化学
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电池技术
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Feng Xiong,Hao Deng,Ruoyin Luo,Shaojie Gao,Chenming Fan,Xin Gao,Bing Li
In this study, a dense Ta-based layer with a thickness of 400 nm was fabricated on SS316N bipolar plates (Ta-SS316N) by using a disproportionation reaction of Ta in a K 2 TaF 7 -Ta(powders)-KCl-NaCl molten salt system at 900 °C for 6 h. According to XRD analysis , the Ta-based layer was mainly composed of metallic Ta as well as Ta 2 N 0.86 . In the simulated HT-PEMFC cathode environment, the corrosion current density of Ta-SS316N obtained from the potentiodynamicl polarization curves was 0.96 μA/cm 2 , which meets the 2025 U S. DOE standard. Compared to the SS316N substrate, Ta-SS316N showed two orders of magnitude higher corrosion resistance and nearly 1 V higher self-corrosion potential, with an interfacial contact resistance of 27.5 mΩ∙cm 2 , accounting for about one-quarter that of SS316N substrate. This provides a low-cost, easy-to-operate method to prepare Ta-based layer on stainless steel bipolar plates used for HT-PEMFC.
研究领域:
材料科学
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电化学
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能源材料
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表面工程
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燃料电池技术
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2018
·
IF 6.653
Zhihao Chen,Jiyuan Jin,Xiaojie Song,Guoyang Zhang,Shujuan Zhang
Whether superoxide radical anion (O2•–) was a key reactive species in the oxidation of arsenite (As(III)) in photochemical processes has long been a controversial issue. With hydroquinone (BQH2) and 1,4-benzoquinone (BQ) as redox mediators, the photochemical oxidation of As(III) and reduction of nitrate (NO3–) was carefully investigated. O2•–, singlet oxygen (1O2), H2O2, and semiquinone radical (BQH•) were all possible reactive species in the irradiated system. However, since the formation of As(IV) is a necessary step in the oxidation of As(III), taking the standard reduction potentials into account, the reactions between the above species and As(III) were thermodynamically unfavorable. On the basis of radical scavenging experiments, hydroxyl radical (•OH) was proved as the key species that led to the oxidation of As(III) in the UV/BQH2 system. It should be noted that the •OH radicals were generated from the photolysis of H2O2, which came from the disproportionation of O2•– and the reaction of O2•– with BQH2. Both the photoejected eaq– from 1(BQH2)* and the direct electron transfer with 3(BQH2)* contributed to the reduction of NO3– in the UV/BQH2 process. No synergistic effect was observed in the redox conversion of As(III) and NO3–, further demonstrating that the role of BQH• was negligible in the studied systems. The results here are helpful for a better understanding of the photochemical behaviors of quinones in the aquatic environment.
研究领域:
环境化学
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光化学
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水化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Zhiyan Yan,Chenrui Liu,Yun Liu,Xiaoqian Tan,Xinyue Li,Yan Shi,Chunlian Ding
Cr(VI) contaminated water usually contains other contaminants like engineered nanomaterials (ENMs). During the process of microbial treatment , the inevitable interaction of Cr(VI), ENMs, and microorganisms probably determines the efficiency of Cr(VI) biotransformation , however, the corresponding information remains elusive. This study investigated the interaction of ZnO nanoparticles (NPs), Cr(VI), and Pannonibacter phragmitetu s BB (hereafter BB), which changed the process of microbial Cr(VI) reduction. ZnO NPs inhibited Cr(VI) reduction, but had no effect on bacterial viability. In particular, Cr(VI) induced BB to produce organic acids and to drive Zn 2+ dissolution from ZnO NPs inside and outside of cells. The dissolved Zn 2+ not only promoted Cr(VI) reduction to Cr(V)/Cr(IV) by strengthening sugar metabolism and inducing increase in NAD(P)H production, but also hindered Cr(V)/Cr(IV) transformation to Cr(III) through down-regulating Cr(VI) reductase genes. A novel bacterial driven ROS scavenging mechanism leading to the inhibition of Cr(VI) reduction was elucidated. Specifically, the accumulated Cr(VI) and Cr(V)/Cr(IV) formed a redox dynamic equilibrium, which triggered the disproportionation of superoxide radicals mimicking superoxide dismutase through the flip-flop of Cr(VI) and Cr(V)/Cr(IV) in bacterial cells. This study provided a realistic insight into design the applicability of biological remediation technology for Cr(VI) contaminant and evaluating environmental risks of ENMs.
研究领域:
环境科学
·
微生物学
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纳米技术
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生物修复
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）