SEPARATION AND PURIFICATION TECHNOLOGY
·
2018
·
IF 3.927
Yalei Ding,Jiejie Wang,Shanshan Xu,Kun-Yi Andrew Lin,Shaoping Tong
In order to completely mineralization of contaminants, it is necessary to develop new methods which can effectively degrade final products of chemical oxidation. Acetic acid (HAc) has been considered one of the typical end products of chemical oxidation of pollutants and thus chosen as a representative target pollutant in the study. Nano-cerium oxide (CeO 2 ), an environment-friendly rare-earth material, was prepared to catalytic ozonation of HAc in acidic solutions. Experimental results show that the prepared CeO 2 could greatly enhance efficiency of H 2 O 2 /O 3 , and also have good stability and recyclability. The Raman spectra indicate that H 2 O 2 interacts with oxygen vacancies of CeO 2 to form peroxide-like species, which could effectively initiate the decomposition of ozone to produce hydroxyl radicals. A mechanism is proposed to explain the activity of peroxide-like species for the decomposition of ozone. The effects of different parameters such as initial pH value, catalyst dosage, and the concentration of H 2 O 2 are also investigated. The results indicate that the CeO 2 /H 2 O 2 /O 3 may provide a convenient and effective method for degrading refractory organic pollutants in acidic wastewaters.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Ting Su,Yunhe Gong,Xue Cui,Xinhong Wang,Yanan Zhang,Hongbin Yu
Oxidizing ammonia to nitrogen is a challenge in wastewater treatment. For this challenge ammonia oxidation via chlorine oxide radicals has been proved to be a potential method. In this study, a space-confined photoanode was designed and prepared by loading RuO 2 nanoparticles on TiO 2 /WO 3 nanowires for in situ enhancing the generation of chlorine oxide radical. Scanning electron microscopy characterization confirmed that RuO 2 nanoparticles were uniformly deposited on TiO 2 /WO 3 nanowires. The generation of chlorine oxide radical was markedly boosted, and its steady-state concentration reached 2.76 × 10 −12 M. This value was 3 times that of the traditional bifacial electrode (a type of electrode that has been widely used for chlorine oxide radical-related research). As a result, ammonia oxidation was greatly enhanced. In 90 min, 31.9 mg/L ammonia nitrogen could be degraded, yet only 0.94 mg/L nitrate was accumulated. In addition, the space-confined photoanode exhibited good performance for real wastewater treatment, and 41.0 mg/L ammonia nitrogen could be oxidized in 135 min. During photoelectrocatalysis, a synergistic index (47.7 %) was obtained. Besides the synergistic effect between photocatalysis and electrocatalysis, the unique morphology and structural design (TiO 2 /WO 3 and RuO 2 were mainly responsible to hydroxyl radical generation and free chlorine production, respectively) also synergistically promoted the generation of chlorine oxide radical, thereby improving ammonia oxidation. The mechanism for ammonia oxidation via chlorine oxide radicals over the space-confined photoanode was proposed based on experimental results and theoretical calculations.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Wen-Xia Zhang,Xi Zhao,Lin-Ya Xu,Shuang Xia,Yu-Fen Zhou,Chong-Lai Chen,Hai-Hua He,Meng-Fei Luo,Jian Chen
The surface Pt species and adsorbed oxygen on the Pt/ZrO 2 catalyst were successfully modulated by altering the preparation methods, resulting in distinct catalytic behaviors for CO, n-heptane, and toluene oxidation. The Pt/ZrO 2 catalyst was initially prepared via wetness impregnation and subsequently reduced in an H 2 atmosphere to obtain the Pt/ZrO 2 -R catalyst. In contrast, the Pt/ZrO 2 -E catalyst was synthesized using ethanol solvent (also serving as a reducing agent) instead of water during wetness impregnation. Moreover, the pre-prepared Pt nanoparticles were loaded onto the ZrO 2 surface using polyvinylpyrrolidine (as a protective and structure directing agent) dissolved in ethanol solvent to fabricate the Pt/ZrO 2 -EP catalyst. Among these catalysts, the Pt/ZrO 2 -R exhibits superior catalytic activity towards CO oxidation due to its abundant metallic Pt species. It is found that activity of Pt/ZrO 2 catalyst for n-heptane oxidation is positively correlated with its surface adsorbed oxygen concentration, thus the highest activity is achieved over the Pt/ZrO 2 -EP catalyst possessing a higher concentration of surface adsorbed oxygen species. Unlike CO and n-heptane oxidation, toluene oxidation activity is affected by multiple factors, it is primarily promoted by synergistic catalysis between metallic Pt species (Pt 0 ) and surface adsorbed oxygen species over the Pt/ZrO 2 -EP catalyst. Our preliminary findings underscore that precise modulation of sensitive active sites on surfaces plays a critical role in specific catalytic reactions.
研究领域:
催化化学
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
TETRAHEDRON
·
2018
·
IF 2.377
Xiaofeng Qiao,Subharanjan Biswas,Wenli Wu,Feng Zhu,Chen-Ho Tung,Yifeng Wang
We report the selective formation of endoperoxides by aerobic TiO 2 photocatalysis through the cyclic addition of dioxygen and a non-conjugated diene , the first heterogeneous catalytic system for endoperoxide synthesis. This green protocol does not require any additive and the photocatalyst is abundant and recyclable, providing a yield up to 64% and >20:1 diastereoselectivity . Mechanistic investigations were carried out by using product analysis, kinetic studies , O-18 labelling experiments, electron-spin resonance and a set of quenching experiments. Superoxide (but not singlet oxygen , triplet oxygen or peroxide) is directly involved in the reaction cascade to form the endoperoxide product. The new findings may be helpful for future for designing eco-friendly and energy sustainable strategies for selective oxygenation reactions using semiconductors, O 2 and sunlight.
研究领域:
化学
·
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
ACS Nano
·
2024
·
IF 15.8
Qingming Deng,Hui Li,Ke Pei,Lok Wing Wong,Xiaodong Zheng,Chi Shing Tsang,Honglin Chen,Wenqian Shen,Thuc Hue Ly,Jiong Zhao,Qiang Fu
High-efficiency catalysts with refined electronic structures are highly desirable for promoting the kinetics of the oxygen evolution reaction (OER) and enhancing catalyst durability. This study comprehensively explores strategies involving metal doping and oxygen vacancies for enhancing the acidic OER catalytic activity of Co3O4. Through extensive screening of 3d and 4d transition metals using density functional theory (DFT) simulations, we demonstrate that the incorporation of metal dopants and oxygen vacancies into Co3O4 potentially triggers a transition from the adsorbate evolution mechanism (AEM) to the lattice oxygen oxidation mechanism (LOM) in the oxygen evolution reaction (OER). While the formation of the O–O bond in the intermediate *OOH poses challenges, a significantly reduced overpotential facilitates efficient conversion of O to O2 through the LOM in *OH and lattice oxygen. Additionally, we find that Mn doping can significantly improve the stability of the catalyst. Building upon the rationale above, we employed a dual doping strategy in subsequent experiments to enhance both the activity and stability. Our final design involved the codoping of Mn and Ru in Co3O4, along with an appropriate amount of oxygen vacancies. This catalyst demonstrates a low overpotential (η10 = 230 mV) compared to pure Co3O4 and maintains stable operation for over 120 h, representing a 12-fold increase. By exploring and harnessing the LOM, more efficient, stable, and cost-effective OER catalysts can be designed, providing crucial support for technologies such as water electrolysis in clean energy.
研究领域:
材料科学
·
催化化学
·
清洁能源技术
✓ 已验证
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2017
·
IF 2.843
Xinxin Zhang,Shiyang Cheng,Wei Zhang,Cai Zhang,Nicholas E. Drewett,Xiyang Wang,Dong Wang,Seung Jo Yoo,Jin-Gyu Kim,Weitao Zheng
Ag/Pr6O11 catalysts supported by either Pr6O11 nanorods (Pr6O11-NRs) or nanoparticles (Pr6O11-NPs) were prepared by conventional incipient wetness impregnation. The nanocomposite of Ag/Pr6O11-NRs demonstrated a higher catalytic activity for CO oxidation than Ag/Pr6O11-NPs at lower temperatures. This improved performance may be ascribed to the mesoporous features and resultant oxygen vacancies of the Pr6O11 nanorods support, as well as the large surface area and homogeneous loading of Ag species. As a result, 98.7 and 100% CO conversions were achieved at 210 and 240 °C for Ag/Pr6O11-NRs, while Ag/Pr6O11-NPs require a temperature of 320 °C to obtain the 100% CO conversion rate. These findings reveal that Pr6O11-NRs is the preferable support, comparative to Pr6O11-NPs, for Ag/Pr6O11 catalysts, for CO oxidation.
研究领域:
催化化学
·
纳米材料科学
·
环境化学
·
表面科学
·
能源化学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2024
·
IF 8.1
Jie Li,Haoran Song,Tao Luo,Yan Cao,Linfeng Zhang,Qun Zhao,Zhanchao Li,Xuewei Hu,Junjie Gu,Senlin Tian
Exposure to ozone (O 3 ) and nitrogen dioxide (NO 2 ) are related to pulmonary dysfunctions and various lung diseases, but the underlying biochemical mechanisms remain uncertain. Herein, the effect of inhalable oxidizing gas pollutants on the pulmonary surfactant (PS, extracted from porcine lungs), a mixture of active lipids and proteins that plays an important role in maintaining normal respiratory mechanics , is investigated in terms of the interfacial chemistry using in-vitro experiments; and the oxidative stress induced by oxidizing gases in the simulated lung fluid (SLF) supplemented with the PS is explored. The results showed that O 3 and NO 2 individually increased the surface tension of the PS and reduced its foaming ability; this was accompanied by the surface pressure-area isotherms of the PS monolayers shifting toward lower molecular areas, with O 3 exhibiting more severe effects than NO 2 . Moreover, both O 3 and NO 2 produced reactive oxygen species (ROS) resulting in lipid peroxidation and protein damage to the PS. The formation of superoxide radicals (O 2 •– ) was correlated with the decomposition of O 3 and the reactions of O 3 and NO 2 with antioxidants in the SLF. These radicals, in the presence of antioxidants, led to the formation of hydrogen peroxide and hydroxyl radicals ( • OH). Additionally, the direct oxidation of unsaturated lipids by O 3 and NO 2 further caused an increase in the ROS content. This change in the ROS chemistry and increased • OH production tentatively explain how inhalable oxidizing gases lead to oxidative stress and adverse health effects. In summary, our results indicated that inhaled O 3 and NO 2 exposure can significantly alter the interfacial properties of the PS, oxidize its active ingredients, and induce ROS formation in the SLF. The results of this study provide a basis for the elucidation of the potential hazards of inhaled oxidizing gas pollutants in the human respiratory system.
研究领域:
生物化学
·
医学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysis Science & Technology
·
2022
·Vol. 12
·期 22
·6827-6837
·
IF 6.177
Penghui Li,Junhua Gao,Jing Shi,Huixiang Wang,Xiangying Xing,Jingzhao Ren,Yu Meng,Liancheng Wang,Baoliang Lv
Linear terminal olefin epoxidation is a significant oxidation reaction for the synthesis of valuable industrial intermediates. As typical olefin epoxidation catalysts, supported tungsten oxides are rich in oxygen vacancies, which have been investigated for improving catalytic performance in other reactions, but the influence on olefin epoxidation is rarely studied. Herein, a series of WO3−x/SBA-15 catalysts with different oxygen vacancy concentrations were obtained by impregnation and sequent hydrogen reduction at 300–600 °C. Their catalytic performances for 1-hexene epoxidation with hydrogen peroxide at 70 °C were studied. It was found that an appropriate concentration of oxygen vacancies could improve epoxidation (the epoxide productivity increased from 135 to 196 μmolepoxide gW−1 min−1) and reduce the apparent activation energy (from 51.6 to 46.9 kJ mol−1). The oxygen vacancies are also beneficial for cycloolefin and other linear olefin epoxidation. In particular, the productivity of cyclooctene oxide was promoted from 4161 to 5744 μmolepoxide gW−1 min−1. This promotion effect was attributed to the increase in the number of Lewis acid sites caused by introducing moderate oxygen vacancies, which could improve the activation of hydrogen peroxide and facilitate epoxidation. In situ FT-IR spectroscopy and density functional theory calculations further indicated that increasing the oxygen vacancies contributes to reducing the energy barrier of the transfer of electrophilic oxygen atoms in active intermediate W–OOH to 1-hexene, thereby promoting epoxidation.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Xiao Wang,Asad Mahmood,Guanhong Lu,Xiaofeng Xie,Jing Sun
The photocatalytic oxidation (PCO) mechanisms of single aromatic hydrocarbons/NO x gases and the synergistic photocatalytic treatment of their mixtures over TiO 2 (anatase) are proposed by analyzing the evolution of adsorbed and gas-phase intermediates through in-situ FTIR and mass-spectroscopy. Photo-activated surface lattice oxygen of TiO 2 (TiO 2 (·O L )) is found to be a strong oxidant for the PCO of both o-xylene and NO x and their consumption led to the deactivation of photocatalysts. As an important coexist air pollutant, NO is firstly discovered as a helper for the persistent ring-opening and degradation of aromatics including o-xylene, toluene, styrene and benzene. NO 2 , a PCO intermediate of NO, acts as a powerful oxidant for replenishing lattice oxygen of TiO 2 , which guarantees the continuous generation of active TiO 2 (·O L ) and prevents the deactivation of photocatalyst. With the introduction of NO, the PCO efficiency of o-xylene increases from ∼65% to 100% and no performance decay of TiO 2 happens in 6 h. The existence of aromatics prevents the escape of toxic NO 2 into air and promotes the harmless transformation of NO into nitrite/nitrate ions and N 2 . This work outlines the essential role of activation and replenishment of lattice oxygen in the PCO process by analyzing the synergistic and stable photocatalytic treatment of aromatic hydrocarbon/NO x mixtures, which explores the practical potentiality of photocatalysis in air purification.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL RESEARCH
·
2025
·
IF 7.7
Zhilun Liu,Lei Zhao,Xu He,Shuang Lu,Peimian Du,Yadong Shen,Jun Ma,Xueyan Li,Fuqiang Guo
Heterogeneous catalytic ozonation is a promising technique for water purification, effectively addressing persistent organic pollutants. This study successfully synthesized oxygen-vacancy-rich Fe 2 O 3 /montmorillonite (Fe-MMT-400) nanocomposites via an integrated calcination strategy for enhanced catalytic ozonation of bisphenol A (BPA). Material characterization confirmed the effective structural integration and dispersion of acicular hematite on MMT substrates. XRD, FTIR, and XPS analyses verified the formation of oxygen vacancies (O V ), while BET measurements revealed an increased specific surface area, promoting ozone decomposition. In degradation experiments, the Fe-MMT-400/O 3 system demonstrated superior performance, achieving 89.9 % BPA removal within 15 min, significantly outperforming ozonation or catalyst-alone systems. Combined electron paramagnetic resonance (EPR) and radical quenching experiments identified surface oxygen atoms (O∗), hydroxyl radicals ( • OH), superoxide radicals (O 2 •– ), and singlet oxygen ( 1 O 2 ) as the reactive oxygen species (ROS), with • OH being the dominant oxidative mediator. Furthermore, multidisciplinary characterization through XPS, DFT calculations, and TPD synergistically confirmed that the engineered O V s served as the primary active sites, crucially facilitating ozone adsorption and dissociation. This work ultimately establishes a comprehensive reaction mechanism framework, delineating the surface-mediated radical and non-radical pathways in the heterogeneous catalytic ozonation processes.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Chun Kong,Chuang Zhi,Zirui Wu,Wenqiang Yang,Juan Yang,Zhongti Sun
NiFe-(oxy)hydroxides are the most active transition metal oxide electrocatalysts for oxygen evolution reaction (OER) under the alkaline media. Herein, we controllably manipulated oxygen vacancy (V O )-tunable NiFe-(oxy) hydroxides that their OER performances possessed a volcano-type relationship with V O concentration, positively-correlated with Ni 3+ /Ni 2+ ratio. Theoretical simulations further unearthed the enhanced activation and dissociation of H 2 O by the inserting of V O . As a result, the optimal sample featuring the Ni 3+ /Ni 2+ ratio of 30.3 % and V O of 23.8 % exhibited the overpotential of 243 mV at the current density of 100 mA cm –2 , simultaneously lasting 120 h durability without any attenuation, exceding the most reported NiFe-(oxy)hydroxides. This work offers an innovative view to understand the OER performance using hypervalent Ni ratio induced by V O defects.
研究领域:
材料科学
·
电化学
·
能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Water Chemistry and Technology
·
2022
·Vol. 44
·期 4
·297-303
·
IF 0.484
Ma Q. G.,Hao Y.,Xue Y. F.,Niu Y. L.,Chang X. L.
Abstract Formaldehyde (HCHO) is a common chemical raw material and one of the major constituents in wastewaters from the production of chemical products. HCHO in wastewater is mainly removed by adsorption, biodegradation, and advanced oxidation. The objective of this study is to investigate transition metal oxides (Fe 2 O 3 , Co 2 O 3 , Ni 2 O 3 , CuO, ZnO) without pretreatment for enhancing the oxidation of HCHO. The oxidation of HCHO in wastewater by hydrogen peroxide using transition metal oxides as catalysts is studied. The concentration of HCHO in waste water was measured by indirect method. HCHO reacts with 2,4-dinitrophenylhydrazine in the presence of acetic acid to produce 2,4-dinitrophenylhydrazone. 2,4-Dinitrophenylhydrazone increases in proportion to the concentration of HCHO. The HCHO removal rate is determined by quantitative analyses of 2,4-dinitrophenylhydrazone using high-performance liquid chromatography (HPLC). The catalytic oxidation experiments are performed in test tubes at 25°C. The results indicate that the catalytic activity of the transition metal oxides towards HCHO oxidation is very different. The removal rate of HCHO was attributed to the number of hydroxyl radicals formed in the system. CuO shows higher catalytic activity in the oxidation of HCHO. The effect of the temperature, the mole ratios of hydrogen peroxide to HCHO, and the amount of CuO on the removal rate of HCHO were studied. Results of experiments show that the HCHO is almost wholly oxidized (>98%) at the best conditions (molar ratio of hydrogen peroxide to HCHO is 2.5, CuO is 0.06 g, 25°C for 15 min). CuO also offers the advantages of simple recovery from the treated solution and repeated use. It is hypothesized that CuO can transform hydrogen peroxide into active oxygen that has higher oxidation activity. But, the rate of formation and removal of free radicals HO· is very fast in the presence of transition metal oxides (Fe 2 O 3 , Co 2 O 3 , Ni 2 O 3 , ZnO).
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）