APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Junhua Zou,Zhitong Wang,Wei Guo,Binbin Guo,Yan Yu,Ling Wu
ZnTi-LDH nanosheets have been synthesized as photocatalysts for selective oxidation of benzyl alcohol (BA) to benzaldehyde (BAD) under visible light irradiation. Based on UV–vis DRS, in-situ FTIR and XPS results, it was revealed that BA would be efficiently chemisorbed and activated on ZnTi-LDH forming the surface coordination species, which contributed to harvesting visible light and induced the photocatalytic reaction. The ESR spectra suggested that oxygen vacancies would be produced in ZnTi-LDHs after the adsorption of BA molecules. More exposed surface OH groups would induce more oxygen vacancies, which would serve as the centers for capturing photoelectrons from the photoexcited surface coordination species and act as active sites for enhanced O 2 adsorption and activation, resulting outstanding photocatalytic activity. Finally, a possible mechanism was proposed to illustrate the photocatalytic process which mediated by surface coordination species formed by the interaction between ZnTi-LDH and BA.
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
JOURNAL OF HAZARDOUS MATERIALS
·
2025
·
IF 11.3
Yue Pan,Haonan Hu,Hongyi Tang,Chunyan Huang,Hao Ma,Wei Xu,Ruimei Fang,Wenyan Xiao,Fan Dong
Surface defect engineering has been regarded as an appealing strategy to improve photocatalytic performance, but defects are susceptible to inactivation and thus lose their function as active sites. In this study, we successfully tailored and identified the dynamic evolution of surface hydroxyl defects over ZnTi-layered double hydroxide (ZnTi-LDH) photocatalyst. The enrichment of surface hydroxyl electrons and the dynamic circulation of hydroxyl defects result in enhanced separation and transport capabilities of photogenerated carriers, thereby ensuring the perpetual activation of small molecules into •O 2 − and •OH. The optimized structure has demonstrated NO removal efficiency values as high as 70.0 %, while concurrently suppressing the emission of NO 2 — a dangerous byproduct. Furthermore, ZnTi-LDH exhibits remarkable adaptability to varying environmental conditions and satisfactory durability over extended periods of reaction. This research offers valuable insights into the key role of surface hydroxyl in sustainable NOx removal technologies, and the findings contribute significantly to the advancement of environmental remediations.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Yuqi Miao,Jianyong He,Xinran Zhu,Guangli Zhu,Shaohang Cao,Guixia Fan,Guosheng Li,Yijun Cao
Current research has trouble explaining the selective flotation mechanism realized by metal ions, which hinders the advancement of effective flotation techniques. In this work, the selective activation flotation of cassiterite from quartz with Pb 2+ is taken as an example to illustrate the pivotal roles of surface hydroxyls in selective flotation. Accordingly, flotation, adsorption amount, and X-ray photoelectron spectroscopy (XPS) measurements and systematic first-principles calculations have been used to investigate the roles of hydroxyl groups on the selective adsorption of Pb 2+ . The obtained flotation, adsorption amount, and XPS test results consistently show that the Pb 2+ can more strongly interplay with cassiterite than quartz resulting in selective flotation of cassiterite from quartz. The electron localization functional results illustrate that the electron localization of oxygen of Si-O bonds is stronger than the Sn-O bond resulting in the weaker electron migration ability (high hardness) of oxygen atoms of quartz than oxygen atoms of cassiterite. This makes the cassiterite surface hydroxyl groups less hard than quartz. Further crystal orbital Hamilton population and partial density of states show that the Pb 2+ interacts with the oxygen atoms on cassiterite forming chemical bonds before and after the adsorption of benzohydroxamic acid (BHA). On the other hand, the interaction of Pb 2+ with quartz is physical in the presence of BHA. The strong adsorption of Pb 2+ on cassiterite makes it easier for BHA adsorption which accounts for the selective flotation of cassiterite from quartz. This work sheds new light on establishing a consistent and dependable theory that the hardness of surface hydroxyls is the original factor affecting the selective adsorption of metal ions on oxide mineral surfaces.
研究领域:
矿物加工工程
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材料科学与工程
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理论化学
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产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2025
·
IF 6.5
Huacheng Ying,Zeyu Wen,Jia Yao,Mowei Zhou,Yongtao Wang,Haoran Li
Constructing N−O bond in amines via aerobic oxidation is of high interest for producing cyclohexanone oxime; however, the mechanism remains disputed. Concerning TiO 2 /NHPI co-catalyzed aerobic oxidation of cyclohexylamine, here a convincing mechanism involving α-C radical and oxaziridine as key intermediates is demonstrated. All the evidences from electron paramagnetic resonance, mass spectrometry, and product analysis with methylated substrates lead to the same story about the mechanism, where both radical translocation of cyclohexylamino radical and epoxidation of 1-hydroperoxycyclohexylamine are mediated by double proton transfer and are the key to convert amine into oxime. Near IR analysis indicate that surface hydroxyl groups on TiO 2 facilitate the double proton transfer process. Here the unveiled role of surface hydroxyl on TiO 2 highlights its potential for broader applications in amine activation. Additionally, the well-established radical mechanism provides valuable insight into the construction of N−O bonds in amines.
研究领域:
化学
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催化反应
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL ENGINEERING
·
2025
·Vol. 151
·期 8
·04025043
·
IF 1.6
Jie Zhang,Mengchen Zong,Ben Dong,Sijie Ge,Shilong He
Quinoline, as one of the typical toxic and refractory organic pollutants in coal chemical industry wastewater, poses a significant threat to human health and environmental quality. In this study, MnCexOy and MnFexOy catalysts were successfully synthesized by doping Ce3+ and Fe2+ into α-MnO2 at a molar ratio of 1∶10 and were applied to the process of catalytic ozonation for the degradation of quinoline. Additionally, a variety of characterization techniques were employed to elucidate the characteristics of the catalysts, including scanning electron microscopy, X-ray diffraction, Brunauer–Emmett–Teller (BET) analysis, X-ray photoelectron spectroscopy, H2-TPR, NH3-TPD. The results show that, in the catalytic ozonation system for quinoline removal, MnCexOy demonstrates excellent quinoline removal efficiency of 87.45%, which is higher than that of MnFexOy (78.83%) and unmodified α-MnO2 (62.67%). By introducing the surface hydroxyl masking agent HPO42−, the significant role of surface hydroxyl groups and oxygen vacancies in the catalytic degradation of quinoline by MnCexOy was further demonstrated. Exploring the surface characteristics of catalysts is beneficial for continued understanding of the active centers of catalysts. Research results will be helpful to the deep treatment and reuse of tailing water of coking wastewater.
研究领域:
环境科学
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催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Jiaqi Li,Mingfei Wang,Jiamin Qi,Xueqian Wang,Langlang Wang,Fei Wang,Kai Li,Yixing Ma,Ping Ning
Hydrogen cyanide (HCN), a common toxic and hazardous air pollutant in industrial exhaust, catalytic hydrolysis of HCN has been the focus of air pollution control research. In this study, a catalyst material (La-TiO 2 ) with high catalytic hydrolysis activity for HCN was obtained by loading La 2 O 3 on the TiO 2 surface, which could realize the complete conversion of HCN at 150 °C with high selectivity of NH 3 and CO 2 . The relevant characterization confirms that La 2 O 3 can be uniformly distributed on the TiO 2 , which can adjust the acid-base structure of the catalyst surface and induce the generation of multi-hydroxyl structures in TiO 2 . On this basis, the combination of in-situ technique and density functional theory (DFT) calculations confirmed that the loading of La 2 O 3 prompted the La-TiO 2 catalyst to activate H 2 O to generate surface hydroxyl groups (-OH), which further enriched the hydroxyl groups on TiO 2 and substantially improved the hydrolysis activity and NH 3 selectivity of the catalyst. And the study confirms that the hydroxyl-rich environment easy combine with the reaction intermediate (formic acid) to generate CO 2 and H 2 O, which accelerated the reaction rate, thus improving the conversion efficiency of HCN and lowering the catalytic conversion temperature. In addition, O 2 can continuously consume the remaining hydrogen atoms after the dissociation of H 2 O to generate hydroxyl groups again, thus effective enhancing catalyst stability. This study provides new theoretical support for the catalytic hydrolysis of HCN and new insights and ideas for the design and development of catalysts for the catalytic hydrolysis of HCN.
研究领域:
环境科学
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催化化学
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产品关联
DOI
高影响因子
ChemCatChem
·
2021
·Vol. 13
·期 19
·4133-4141
·
IF 5.686
Lina Zhang,Bangjie Zhang,Peng Xue,Jiwei Li,Zhun Zhang,Yanling Yang,Shuai Wang,Jingdong Lin,Honggang Liao,Yong Wang,Yali Yao,Shaolong Wan,Haifeng Xiong
Graphical Room temperature oxidation : Pretreatment methods affect the nature of the Pd species and the reactivity of Pd/Al 2 O 3 in formaldehyde oxidation at room temperature. The steam treatment (H 2 O/Ar) increased the metal Pd dispersion, and generated more active hydroxyl groups, leading to the enhanced reactivity in formaldehyde oxidation. A Pd/Al 2 O 3 nanocatalyst was pretreated at 750 °C in air, Ar or H 2 O/Ar, respectively. The effect of these different pretreatments on the active species and reactivity of Pd/Al 2 O 3 in formaldehyde oxidation at room temperature was investigated. The pretreatment was found to affect both the phase transformation of PdO to Pd metal and the Pd dispersion, leading to different catalytic performances. We found that the Pd/Al 2 O 3 nanocatalyst pretreated in both Ar and H 2 O/Ar show 60 % and 100 % formaldehyde conversion at 25 °C, respectively, while the catalyst pretreated in air is not active under the same condition. Pretreatments in both Ar and H 2 O/Ar were found to facilitate the formation of metallic Pd on Pd/Al 2 O 3 catalyst, confirmed by both experiments and calculation based on the function of the equilibrium oxygen pressure and temperature. We further found that the catalyst pretreated in H 2 O/Ar has higher Pd dispersion and more surface OH groups compared to that pretreated in Ar, leading to improved activity in formaldehyde oxidation.
研究领域:
催化化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOILS AND SEDIMENTS
·
2023
·Vol. 23
·期 6
·2473-2481
·
IF 3.6
Li Ke-wei,Lu Hai-long,Nkoh Nkoh Jackson,Xu Ren-kou
Purpose Phyllosilicate minerals are the important components in soils and an important source of activated aluminum (Al) during soil acidification. However, the mechanisms for Al activation in phyllosilicate minerals were not understood well. This study was designed to investigate the role of hydroxyl groups on the surface of montmorillonite in acidification-induced activation of solid aluminum. Materials and methods Montmorillonite was treated at high temperatures to remove the hydroxyl groups from its surface, and then XRD, FTIR, and 27 Al NMR of montmorillonite before and after high-temperature treatment were determined. After that, Al activation during acidification of montmorillonite treated at different temperatures was investigated using the constant pH titration method. Results and discussion The results showed that hydroxyl groups on the surface of montmorillonite can effectively be removed when the temperature was raised to 670 °C. After high-temperature treatment, the crystallinity of the montmorillonite was reduced. The montmorillonite layer space was reduced, the pH and cation exchange capacity (CEC) of the mineral were decreased, and consequently the amount of acid consumed during acidification was significantly reduced. The decrease of CEC and surface hydroxyl groups in the mineral was responsible for the reduction in acid consumption during mineral acidification. After high-temperature treatment, the Al coordination structure of montmorillonite was transformed from six-coordination to four-coordination. The removal of surface hydroxyl groups inhibited the activation of Al during montmorillonite acidification, and the inhibition effect was increased with increasing temperatures below the complete dehydroxylation point. Conclusions The activation of Al during montmorillonite acidification was inhibited, suggesting that the hydroxyl groups at the edge of montmorillonite played an important role in Al activation process.
研究领域:
土壤学
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矿物学
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产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 53
·80399-80410
·
IF 5.19
Shu Xinpeng,Bi Huaqi,Wang Jun,Yang Jiaxin,Wang Jue,Liu Guangqing,Su Bensheng
Catalytic ozonation with supported metal oxides is a promising strategy for addressing refractory pollutants in wastewater. In this study, γ-Al 2 O 3 supported MnO x -CeO x catalysts (MC 1 , MC 2 , and MC 3 ) obtained at different calcination temperatures (400 °C, 550 °C, and 700 °C) were applied as effective catalysts for ozonation and explored the feasibility of the treatment of oxytetracycline (OTC) wastewater. Comparatively, the MC 2 possessed the highest molar ratios of Mn 3+ /Mn 4+ (1.60) and Ce 3+ /Ce 4+ (0.96), the largest surface area (273.8 m 2 g −1 ) with a petal-shaped structure, and most abundant surface hydroxyls (3.78 mmol g −1 ). These physicochemical characteristics benefited the surface reaction and resulted in the acceleration of ozone decomposition, electron transfer, and •OH generation, thereby improving the catalyst’s adsorption ability and catalytic activity. The combination with MC 2 increased the OTC and COD removal of the ozonation process from 59.1% and 29.0% to 94.7% and 83.3% in 25 min, respectively. By employing electron paramagnetic resonance (EPR) and radical quenching experiments, it was verified that •OH species generation promoted the mineralization of OTC. The possible degradation pathways of OTC were investigated through mass spectrometry, and the route consisted of dehydration, deamination, and demethylation. Moreover, during a 12-day continuous experiment, MC 2 catalyst exhibited excellent reusability and catalytic stability, with COD removal efficiencies above 80%.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2021
·Vol. 23
·期 12
·1-12
·
IF 2.253
Pan Meng,Teng Xuegang,Li Mengxia,Pan Xianfeng,Liao Qiyong,Cheng Wenxiang,Yang Renchun
TiO 2 nanosheets have a great potential in photocatalytic H 2 evolution, but they suffer from low catalytic activity at present. Although the surface modification has been extensively used to improve the catalytic performance, regulating the surface functional groups of TiO 2 nanosheets to enhance the photocatalytic activity has been largely overlooked. In this study, we attempt to tailor the surface properties of TiO 2 nanosheets by adjusting the surface functional groups so as to improve their photocatalytic H 2 production activity. With adding a small amount of alcohols in the synthesis system, the surface hydroxyl groups of TiO 2 nanosheets were regulated successfully. Interestingly, the TiO 2 nanosheets prepared with adding ethylene glycol possess the significantly more surface hydroxyl groups and exhibit a narrower bandgap, a higher hydrophilicity, and a slower recombination rate of photo-induced carriers than the conventional nanosheets. Benefit from these special properties, the ability of the hydroxyl-rich TiO 2 nanosheets to photocatalyze H 2 evolution is obviously improved.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry C
·
2022
·
IF 4.177
Rui Wang,Zhenchao Zhao,Pan Gao,Kuizhi Chen,Zhehong Gan,Qiang Fu,Guangjin Hou
The dehydration of alcohols to value-added chemicals using alumina catalysts has been industrialized decades ago; however, despite years of fundamental research, the molecular-level understanding of the reaction process is still lacking. Herein, the dehydration reactions of ethanol on two representative aluminas, i.e., γ-Al2O3 and five-coordinated Al-rich Al2O3-nanosheet (Al2O3-NS), are comparatively investigated by a combination of solid-state NMR spectroscopy and reaction evaluations. NMR results reveal that the presence of hydroxyl groups nearby the Lewis acid sites (LASs) leads to different ethanol adsorption modes. The surface hydroxyls nearby LASs interfere with ethanol adsorption, which causes the methyl group to move away from the alumina surface and hinders the elimination of β-H, resulting in low reaction activity. In addition, the desorption property of surface hydroxyls will affect the dehydration reaction as they participate in the catalytic reaction cycles. Such effects may also explain the lower reaction activities for diethyl ether to ethylene compared with ethanol. Although both four- and five-coordinated Als are the possible active sites for ethanol dehydration, the reactivity of alcohol dehydration may also be substantially affected by the local environment of undercoordinated Als besides coordination numbers. These new insights demonstrate that the host–guest interaction regulated by the local environment of active sites plays an important role in the catalytic reaction.
研究领域:
催化化学
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材料科学
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物理化学
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 36
·17026-17031
·
IF 3.3
Ya-Jiao Zhang,Shi-Tian Xiao,Yi-Tian Wang,Feng-Juan Wu,Si-Ming Wu,Lu Wu,Fu-Fei Pu,Li-Ying Wang,Ge Tian,Cong-Yun Huang,Xiao-Yu Yang
Hierarchical TiO2 nanofibers with enriched surface hydroxyl groups and oxygen vacancies have been synthesized. An assessment of their photocatalytic properties shows that the new catalyst has high stability and exhibits excellent photocatalytic H2 production performance in seawater. The enhanced activity of the catalyst is a consequence of the elevation in the rates of charge transfer and H+ adsorption by the synergistic effects of surface hydroxyls and oxygen vacancies.
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
危险品化学品经营许可证（带存储）