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Heterogeneous reaction mechanism of gaseous HNO

Nan ZHAO,Qingzhu ZHANG,Wenxing WANG

《环境科学与工程前沿（英文）》 2016年 第10卷 第5期 doi: 10.1007/s11783-016-0836-z

摘要： We studied the heterogeneous reaction mechanism of gaseous HNO with solid NaCl. HCl is released from heterogeneous reactions between gaseous HNO and solid NaCl. Water molecules induce surface reconstruction of NaCl to facilitate the reaction. Sea salt particles containing NaCl are among the most abundant particulate masses in coastal atmosphere. Reactions involving sea salt particles potentially generate Cl radicals, which are released into coastal atmosphere. Cl radicals play an important role in the nitrogen and O cycles, sulfur chemistry and particle formation in the troposphere of the polluted coastal regions. This paper aimed at the heterogeneous reaction between gaseous HNO and solid NaCl. The mechanism was investigated by density functional theory (DFT). The results imply that water molecules induce the surface reconstruction, which is essential for the heterogeneous reaction. The surface reconstruction on the defective (710) surface has a barrier of 10.24 kcal·mol and is endothermic by 9.69 kcal·mol , whereas the reconstruction on the clean (100) surface has a barrier of 18.46 kcal·mol and is endothermic by 12.96 kcal·mol . The surface reconstruction involved in water-adsorbed (710) surface is more energetically favorable. In comparison, water molecules adsorbed on NaCl (100) surface likely undergo water diffusion or desorption. Further, it reveals that the coordination number of the Cl is reduced after the surface reconstruction, which assists Cl to accept the proton from HNO . HCl is released from heterogeneous reactions between gaseous HNO and solid NaCl and can react with OH free radicals to produce atomic Cl radicals. The results will offer further insights into the impact of gaseous HNO on the air quality of the coastal areas.

关键词： Seasalt particles     NaCl     HNO3     Heterogeneous reaction     Reaction mechanism     Density functional theory    

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Impact and inhibitory mechanism of phenolic compounds on the formation of toxic Maillard reaction products

Jing TENG, Xiaoqian HU, Ningping TAO, Mingfu WANG

《农业科学与工程前沿（英文）》 2018年 第5卷 第3期   页码 321-329 doi: 10.15302/J-FASE-2017182

摘要：

As one of the dominant reactions occurring during thermal treatment of food, the Maillard reaction not only leads to the formation of aroma, browning color and taste compounds, but also contributes to the formation of some unpleasant toxic substances including acrylamide, heterocyclic amines and advanced glycation end products. Polyphenols, one of the most abundant antioxidants in the human diet, are contained in different kinds of foods. In this review, some recent studies on the impact of dietary polyphenols on the formation of acrylamide, heterocyclic amines and advanced glycation end products formed during the Maillard reaction are summarized, including the research work conducted with both chemical model systems and real food model systems; the possible inhibitory mechanisms of different polyphenols are also summarized and discussed in this review. Basically we found that some dietary polyphenols not only scavenge free radicals, but also react with reactive carbonyl species, thus lowering the formation of toxic Maillard reaction products. This review provides a useful theoretical foundation for the application of polyphenols in food safety, and suggests some directions for further study of natural products as inhibitors against the formation of toxic substances in thermally processed food.

关键词： advanced glycation end products     acrylamide     food safety     heterocyclic amine     Maillard reaction     polyphenols    

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碱硅酸反应与碱碳酸盐反应

唐明述

《中国工程科学》 2000年 第2卷 第1期   页码 34-40

摘要：

碱集料反应（AAR）可分为两类，即碱硅酸反应（ASR）与碱碳酸盐反应（ACR）。二者的共同点是与碱发生的化学反应可导致混凝土中集料的体积增大，从而可能使混凝土甚至整个建筑物或构筑物发生膨胀开裂。文章着重从膨胀过程和机理以及岩石的结构特征探讨二者的特性与差异。ASR类型岩石具有碱活性的前提条件是较低的二氧化硅结晶完整度。只有隐晶质、微晶质、玻璃质或发生过应变的二氧化硅才会具有较高的化学活性，导致混凝土破坏。通过系统研究证实，对碱碳酸盐反应，虽然结晶的完整程度以及白云石（CaCO3·MgCO3）分子式中Ca/Mg比也将影响其与碱反应的速率，但起决定作用的是白云石晶体的尺寸及其在岩石中的分布状态和被基质包围的紧密程度。从微观结构得出的这些特征将有助于加深对碱集料反应膨胀机理的认识。文中还介绍了形成活性白云石的地质环境和碱硅酸反应与碱碳酸盐反应的区分方法。

关键词： 碱     集料     硅酸     碳酸盐     混凝土开裂     机理    

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Solid-state NMR for metal-containing zeolites: From active sites to reaction mechanism

Xingling Zhao, Jun Xu, Feng Deng

《化学科学与工程前沿（英文）》 2020年 第14卷 第2期   页码 159-187 doi: 10.1007/s11705-019-1885-1

摘要： Metal-containing zeolite catalysts have found a wide range of applications in heterogeneous catalysis. To understand the nature of metal active sites and the reaction mechanism over such catalysts is of great importance for the establishment of structure-activity relationship. The advanced solid-state NMR (SSNMR) spectroscopy is robust in the study of zeolites and zeolite-catalyzed reactions. In this review, we summarize recent developments and applications of SSNMR for exploring the structure and property of active sites in metal-containing zeolites. Moreover, detailed information on host-guest interactions in the relevant zeolite catalysis obtained by SSNMR is also discussed. Finally, we highlight the mechanistic understanding of catalytic reactions on metal-containing zeolites based on the observation of key surface species and active intermediates.

关键词： metal-containing zeolites     solid-state NMR     active site     host-guest interaction     reaction mechanism    

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Extraction of hydrogen chloride by a coupled reaction-solvent extraction process

Yunzhao Li,Xingfu Song,Guilan Chen,Shuying Sun,Yanxia Xu,Jianguo Yu

《化学科学与工程前沿（英文）》 2015年 第9卷 第4期   页码 479-487 doi: 10.1007/s11705-015-1512-8

摘要： A coupled reaction-solvent extraction process was used to remove HCl from a simulated distiller waste. The extraction performances of various extractants and diluents were compared and the apparent basicity of N235 (a mixture of tertiary amines) in various diluents was determined. The best results were obtained using N235 and isoamyl alcohol as the extractant and diluent, respectively. The yield of HCl from the coupled extraction was 75% with this extraction system. The mechanisms for the removal of HCl in both the direct and coupled extractions were investigated. For the coupled extraction, the formation of an R NHCl ion-pair complex was involved in the HCl removal. For the direct extraction, the mechanism involved the formation of hydrogen bonds at high concentrations of HCl.

关键词： hydrogen chloride     distiller waste     coupled reaction and solvent extraction     N235     extraction mechanism    

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Experimental research on catalysts and their catalytic mechanism for hydrogen production by gasification

PEI Aixia, GUO Liejin, JIN Hui

《能源前沿（英文）》 2007年 第1卷 第4期   页码 451-456 doi: 10.1007/s11708-007-0066-2

摘要： Peanut shell, mixed with sodium carboxymethylcellulose, was gasified at a temperature of 450°C and a pressure range from 24 to 27 MPa with the presence of different catalysts, including KCO, ZnCl and Raney-Ni. The experimental results show that different catalysts have greatly different effects on the reaction. Gasification efficiency (GE), hydrogen gasification efficiency (GHE), carbon gasification efficiency (GCE), yield of hydrogen production ( ) and potential yield of hydrogen production () are applied to describe the catalytic efficiency. From the result of gaseous components, ZnCl has the highest hydrogen selectivity, KCO is lower, and Raney-Ni is the lowest, but Raney-Ni is the most favorable to gasify biomass among the three catalysts, and its , , reach 126.84%, 185.71%, 94.24%, respectively. As expected, hydrogen selectivity increased and CH reduced rapidly when the mixture of ZnCl and Raney-Ni is used under the same condition. The optimization mixture appeared when 0.2 g of ZnCl was added to 1 g of Raney-Ni, 43.56 g · kg of hydrogen pro duction was obtained. In addition, the catalytic mechanisms of different catalysts were analyzed, and the possible reaction pathway was brought forward, which helped to explain the experiment phenomena and results correctly.

关键词： presence     Raney-Ni     biomass     optimization mixture     possible reaction    

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Operando modeling and measurements: Powerful tools for revealing the mechanism of alkali carbonate-based

《能源前沿（英文）》 2023年 第17卷 第3期   页码 380-389 doi: 10.1007/s11708-023-0872-x

摘要： Alkali carbonate-based sorbents (ACSs), including Na2CO3- and K2CO3-based sorbents, are promising for CO2 capture. However, the complex sorbent components and operation conditions lead to the versatile kinetics of CO2 sorption on these sorbents. This paper proposed that operando modeling and measurements are powerful tools to understand the mechanism of sorbents in real operating conditions, facilitating the sorbent development, reactor design, and operation parameter optimization. It reviewed the theoretical simulation achievements during the development of ACSs. It elucidated the findings obtained by utilizing density functional theory (DFT) calculations, ab initio molecular dynamics (AIMD) simulations, and classical molecular dynamics (CMD) simulations as well. The hygroscopicity of sorbent and the humidity of gas flow are crucial to shifting the carbonation reaction from the gas−solid mode to the gas−liquid mode, boosting the kinetics. Moreover, it briefly introduced a machine learning (ML) approach as a promising method to aid sorbent design. Furthermore, it demonstrated a conceptual compact operando measurement system in order to understand the behavior of ACSs in the real operation process. The proposed measurement system includes a micro fluidized-bed (MFB) reactor for kinetic analysis, a multi-camera sub-system for 3D particle movement tracking, and a combined Raman and IR sub-system for solid/gas components and temperature monitoring. It is believed that this system is useful to evaluate the real-time sorbent performance, validating the theoretical prediction and promoting the industrial scale-up of ACSs for CO2 capture.

关键词： CO2 capture     carbonation     theoretical modeling     operando techniques     reaction visualization    

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Numerical study of ignition mechanism of n-heptane direct injection compression-ignition engine

Xiaoping GUO, Zhanjie WANG,

《能源前沿（英文）》 2009年 第3卷 第4期   页码 432-439 doi: 10.1007/s11708-009-0050-9

摘要： A detailed chemical dynamical mechanism of oxidation of n-heptane was implemented into kiva-3 code to study the ignition mechanism of a high-temperature, high-pressure, three-dimensional-space, transient turbulent, non-homogeneous, mono-component fuel in the engine. By testing the quantity of the heat released by the chemical reaction within the cylinder cell, the elementary reaction showing an obvious increase in the cell temperature was defined as ignition reaction and the corresponding cell as ignition position. The main pathway of the ignition reaction was studied by using the reverse deducing method. The result shows that the ignition in the engine can be divided into low-temperature ignition and high-temperature ignition, both of which follow the same rule in releasing heat, called the impulse heat releasing feature. Low-temperature ignition reaction, whose ignition reaction is c5h9o1-4=ch3cho+c3h5-a, follows the oxidation mechanism, while high-temperature ignition reaction, whose ignition reaction is c2h3o1-2=ch3co, follows the decomposition mechanism. No matter which ignition it is in, the chemical reaction that restrains the ignition reaction from lasting is the deoxidization reaction of alkylperoxy radicals.

关键词： compression-ignition engine     ignition mechanism     elementary reaction     n-heptane    

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Catalytic combustion of volatile organic compounds using perovskite oxides catalysts—a review

《化学科学与工程前沿（英文）》 2023年 第17卷 第11期   页码 1649-1676 doi: 10.1007/s11705-023-2324-x

摘要： With the rapid development of industry, volatile organic compounds (VOCs) are gaining attention as a class of pollutants that need to be eliminated due to their adverse effects on the environment and human health. Catalytic combustion is the most popular technology used for the removal of VOCs as it can be adapted to different organic emissions under mild conditions. This review first introduces the hazards of VOCs, their treatment technologies, and summarizes the treatment mechanism issues. Next, the characteristics and catalytic performance of perovskite oxides as catalysts for VOC removal are expounded, with a special focus on lattice distortions and surface defects caused by metal doping and surface modifications, and on the treatment of different VOCs. The challenges and the prospects regarding the design of perovskite oxides catalysts for the catalytic combustion of VOCs are also discussed. This review provides a reference base for improving the performance of perovskite catalysts to treat VOCs.

关键词： perovskite oxides     volatile organic compounds     catalytic combustion     reaction mechanism    

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Secondary aerosol formation in winter haze over the Beijing-Tianjin-Hebei Region, China

Dongjie Shang, Jianfei Peng, Song Guo, Zhijun Wu, Min Hu

《环境科学与工程前沿（英文）》 2021年 第15卷 第2期 doi: 10.1007/s11783-020-1326-x

摘要： Abstract • Characteristics and interannual variation of aerosol pollution are illustrated. • Mechanisms of secondary aerosol formation in winter haze of North China are reviewed. • Directions in future studies of secondary aerosol formation are provided. Severe haze pollution occurs frequently in the winter over the Beijing-Tianjin-Hebei (BTH) region (China), exerting profound impacts on air quality, visibility, and human health. The Chinese Government has taken strict mitigation actions since 2013 and has achieved a significant reduction in the annual mean PM2.5 concentration over this region. However, the level of secondary aerosols during heavy haze episodes showed little decrease during this period. During heavy haze episodes, the concentrations of secondary aerosol components, including sulfate, nitrate and secondary organics, in aerosol particles increase sharply, acting as the main contributors to aerosol pollution. To achieve effective control of particle pollution in the BTH region, the precise and complete secondary aerosol formation mechanisms have been investigated, and advances have been made about the mechanisms of gas phase reaction, nucleation and heterogeneous reactions in forming secondary aerosols. This paper reviews the research progress in aerosol chemistry during haze pollution episodes in the BTH region, lays out the challenges in haze formation studies, and provides implications and directions for future research.

关键词： Secondary aerosol formation     Regional haze     Photochemical reaction     Aqueous reaction     Chemical mechanism    

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Kinetics and mechanism of nitrobenzene degradation by hydroxyl radicals-based ozonation process enhanced

Weizhou Jiao, Shengjuan Shao, Peizhen Yang, Kechang Gao, Youzhi Liu

《化学科学与工程前沿（英文）》 2021年 第15卷 第5期   页码 1197-1205 doi: 10.1007/s11705-020-1998-6

摘要： This study investigated the indirect oxidation of nitrobenzene (NB) by hydroxyl radicals (·OH) in a rotating packed bed (RPB) using competitive kinetics method with -nitrochlorobenzene as a reference compound. The rate constants of NB with ·OH are calculated to be between (1.465±0.113) × 10 L/(mol·s) and (2.497±0.192) × 10 L/(mol·s). The experimental data are fitted by the modified Arrhenius equation, where the activation energy is 4877.74 J/mol, the order of NB concentration, rotation speed, and initial pH is 0.2425, 0.1400 and 0.0167, respectively. The ozonation process of NB could be enhanced by RPB, which is especially effective for highly concentrated NB-containing wastewater under alkaline conditions. The high gravity technology can accelerate ozone mass transfer and self-decomposition of ozone to produce more ·OH, resulting in an increase in the indirect oxidation rate of NB by ·OH and consequently effective degradation of NB in wastewater.

关键词： high gravity technology     hydroxyl radicals     nitrobenzene     reaction kinetics    

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Characterization of chlorine dioxide as disinfectant for the removal of low concentration microcystins

Mingsong WU, Junli HUANG, Yuling ZHANG, Shijie YOU, Shaofeng LI, Zhilin RAN, Yu TIAN

《环境科学与工程前沿（英文）》 2012年 第6卷 第1期   页码 75-81 doi: 10.1007/s11783-011-0331-5

摘要： Microcystins, which represents one kind of cancerogenic organic compounds, is abundant in eutrophication water. The effects of reaction factors on chlorine dioxide (ClO ) for removal of low-concentration Microcystin-LR, Microcystin-RR, and Microcystin-YR in water as well as the reaction mechanisms was investigated by using enzyme-linked immunosorbent assay (ELISA) kit and gas chromatography–mass spectrometry (GC-MS). The results showed that MC-LR, MC-RR, and MC-YR could be efficiently decomposed by ClO . The degradation efficiency was shown positively correlated to the concentration of ClO and reaction time; while the effect of reaction temperature and pH is slight. The kinetic constants and activation energies of the reaction of MC-LR, MC-RR, and MC-YR with ClO are determined as 459.89, 583.15, 488.43 L·(mol·min) and 64.78, 53.01, 59.15 kJ·mol , respectively. As indicated by high performance liquid chromatography mass spectrometer (HPLC-MS) analysis, degradation should be accomplished via destruction of Adda group by oxidation, with the formation of dihydroxy substituendums as end products. This study has provided a fundamental demonstration of ClO serving as oxidizing disinfectant to eliminate microcystins from raw water source.

关键词： disinfection     chlorine dioxide     microcystins     reaction mechanism    

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Superior performance in visible-light-driven hydrogen evolution reaction of three-dimensionally ordered

《化学科学与工程前沿（英文）》 2021年 第15卷 第6期   页码 1561-1571 doi: 10.1007/s11705-021-2089-z

摘要： It is of broad interest to develop emerging photocatalysts with excellent light-harvesting capacity and high charge carrier separation efficiency for visible light photocatalytic hydrogen evolution reaction. However, achieving satisfying hydrogen evolution efficiency under noble metal-free conditions remains challenging. In this study, we demonstrate the fabrication of three-dimensionally ordered macroporous SrTiO3 decorated with ZnxCd1−xS nanoparticles for hydrogen production under visible light irradiation (λ>420 nm). Synergetic enhancement of photocatalytic activity is achieved by the slow photon effect and improved separation efficiency of photogenerated charge carriers. The obtained composites could afford very high hydrogen production efficiencies up to 19.67 mmol·g−1·h−1, with an apparent quantum efficiency of 35.9% at 420 nm, which is 4.2 and 23.9 times higher than those of pure Zn0.5Cd0.5S (4.67 mmol·g−1·h−1) and CdS (0.82 mmol·g−1·h−1), respectively. In particular, under Pt-free conditions, an attractive hydrogen production rate (3.23 mmol·g−1·h−1) was achieved, providing a low-cost and high-efficiency strategy to produce hydrogen from water splitting. Moreover, the composites showed excellent stability, and no obvious loss in activity was observed after five cycling tests.

关键词： three-dimensionally ordered macroporous SrTiO3     ZnxCd1–xS     visible light     hydrogen production     promotion mechanism    

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Reaction mechanism of arsenic capture by a calcium-based sorbent during the combustion of arsenic-contaminated

Mei Lei, Ziping Dong, Ying Jiang, Philip Longhurst, Xiaoming Wan, Guangdong Zhou

《环境科学与工程前沿（英文）》 2019年 第13卷 第2期 doi: 10.1007/s11783-019-1110-y

摘要：

Pilot-scale combustion is required to treat arsenic-enriched biomass in China.

CaO addition to arsenic-enriched biomass reduces arsenic emission.

CaO captures arsenic via chemical adsorption to form Ca3(AsO4)2.

关键词： Arsenic contamination     Phytoremediation     Emission control     Calcium-based sorbent     Biomass disposal     Pilot-scale combustion    

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A combined experimental and theoretical study of micronized coal reburning

Hai ZHANG, Jiaxun LIU, Jun SHEN, Xiumin JIANG

《能源前沿（英文）》 2013年 第7卷 第1期   页码 119-126 doi: 10.1007/s11708-012-0226-6

摘要： Micronized coal reburning (MCR) can not only reduce carbon in fly ash but also reduce NO emissions as compared to the conventional coal reburning. However, it has two major kinetic barriers in minimizing NO emission. The first is the conversion of NO into hydrogen cyanide (HCN) by conjunction with various hydrocarbon fragments. The second is the oxidation of HCN by association with oxygen-containing groups. To elucidate the advantages of MCR, a combination of Diffuse Reflection Fourier Transform Infrared (FTIR) experimental studies with Density Functional Theory (DFT) theoretical calculations is conducted in terms of the second kinetic barrier. FTIR studies based on Chinese Tiefa coal show that there are five hydroxide groups such as OH-π, OH-N, OH-OR , self-associated OH and free OH. The hydroxide groups increase as the mean particle size decreases expect for free OH. DFT calculations at the B3LYP/6-31 G(d) level indicate that HCN can be oxidized by hydroxide groups in three paths, HCN+OH→HOCN+H (path 1), HCN+OH→HNCO+H (path 2), and HCN+OH→CN+H O (path 3). The rate limiting steps for path 1, path 2 and path 3 are IM2→P1+H (170.66 kJ/mol activated energy), IM1→IM3 (231.04 kJ/mol activated energy), and R1+OH→P3+H O (97.14 kJ/mol activated energy), respectively. The present study of MCR will provide insight into its lower NO emission and guidance for further studies.

关键词： hydroxyl radicals     Fourier transform infrared spectroscopy (FTIR)     density functional theory (DFT)     homogeneous reaction mechanism     NOx    

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标题 作者 时间 类型 操作

Heterogeneous reaction mechanism of gaseous HNO

Nan ZHAO,Qingzhu ZHANG,Wenxing WANG

期刊论文

Impact and inhibitory mechanism of phenolic compounds on the formation of toxic Maillard reaction products

Jing TENG, Xiaoqian HU, Ningping TAO, Mingfu WANG

期刊论文

碱硅酸反应与碱碳酸盐反应

唐明述

期刊论文

Solid-state NMR for metal-containing zeolites: From active sites to reaction mechanism

Xingling Zhao, Jun Xu, Feng Deng

期刊论文

Extraction of hydrogen chloride by a coupled reaction-solvent extraction process

Yunzhao Li,Xingfu Song,Guilan Chen,Shuying Sun,Yanxia Xu,Jianguo Yu

期刊论文

Experimental research on catalysts and their catalytic mechanism for hydrogen production by gasification

PEI Aixia, GUO Liejin, JIN Hui

期刊论文

Operando modeling and measurements: Powerful tools for revealing the mechanism of alkali carbonate-based

期刊论文

Numerical study of ignition mechanism of n-heptane direct injection compression-ignition engine

Xiaoping GUO, Zhanjie WANG,

期刊论文

Catalytic combustion of volatile organic compounds using perovskite oxides catalysts—a review

期刊论文

Secondary aerosol formation in winter haze over the Beijing-Tianjin-Hebei Region, China

Dongjie Shang, Jianfei Peng, Song Guo, Zhijun Wu, Min Hu

期刊论文

Kinetics and mechanism of nitrobenzene degradation by hydroxyl radicals-based ozonation process enhanced

Weizhou Jiao, Shengjuan Shao, Peizhen Yang, Kechang Gao, Youzhi Liu

期刊论文

Characterization of chlorine dioxide as disinfectant for the removal of low concentration microcystins

Mingsong WU, Junli HUANG, Yuling ZHANG, Shijie YOU, Shaofeng LI, Zhilin RAN, Yu TIAN

期刊论文

Superior performance in visible-light-driven hydrogen evolution reaction of three-dimensionally ordered

期刊论文

Reaction mechanism of arsenic capture by a calcium-based sorbent during the combustion of arsenic-contaminated

Mei Lei, Ziping Dong, Ying Jiang, Philip Longhurst, Xiaoming Wan, Guangdong Zhou

期刊论文

A combined experimental and theoretical study of micronized coal reburning

Hai ZHANG, Jiaxun LIU, Jun SHEN, Xiumin JIANG

期刊论文