Search | Engineering

订阅投稿

首页学术期刊学术焦点学术视频工程成就工程前沿关于我们 English

资源类型

期刊论文 201

会议视频 2

年份

2023 24

2022 19

2021 22

2020 8

2019 11

2018 15

2017 4

2016 7

2015 7

2014 2

2013 10

2012 8

2011 13

2010 10

2009 11

2008 8

2007 13

2005 1

2004 1

2001 1

展开︾

关键词

催化剂 2

反应模型 2

热力学 2

&alpha 1

Al-Cr203体系 1

COVID-19 1

DNA计算 1

PCR核酸检测 1

Pd局域环境 1

sn-2棕榈酸甘油酯 1

一维（1D） 1

三相界面 1

两个反应区 1

中子测量 1

乙炔半加氢 1

乙烷干重整 1

二氧化碳 1

产氧反应 1

人乳替代脂 1

展开︾

检索范围：

排序：展示方式：

Thermodynamic analysis of reaction pathways and equilibrium yields for catalytic pyrolysis of naphtha

《化学科学与工程前沿（英文）》 2022年第16卷第12期页码 1700-1712 doi: 10.1007/s11705-022-2207-6

摘要： The chain length and hydrocarbon type significantly affect the production of light olefins during the catalytic pyrolysis of naphtha. Herein, for a better catalyst design and operation parameters optimization, the reaction pathways and equilibrium yields for the catalytic pyrolysis of C_5–8 n/iso/cyclo-paraffins were analyzed thermodynamically. The results revealed that the thermodynamically favorable reaction pathways for n/iso-paraffins and cyclo-paraffins were the protolytic and hydrogen transfer cracking pathways, respectively. However, the formation of light paraffin severely limits the maximum selectivity toward light olefins. The dehydrogenation cracking pathway of n/iso-paraffins and the protolytic cracking pathway of cyclo-paraffins demonstrated significantly improved selectivity for light olefins. The results are thus useful as a direction for future catalyst improvements, facilitating superior reaction pathways to enhance light olefins. In addition, the equilibrium yield of light olefins increased with increasing the chain length, and the introduction of cyclo-paraffin inhibits the formation of light olefins. High temperatures and low pressures favor the formation of ethylene, and moderate temperatures and low pressures favor the formation of propylene. n-Hexane and cyclohexane mixtures gave maximum ethylene and propylene yield of approximately 49.90% and 55.77%, respectively. This work provides theoretical guidance for the development of superior catalysts and the selection of proper operation parameters for the catalytic pyrolysis of C_5–8 n/iso/cyclo-paraffins from a thermodynamic point of view.

关键词： naphtha catalytic pyrolysis reaction pathway equilibrium yield

HTML PDF 收藏

催化裂化过程反应化学的进展

许友好,汪燮卿

《中国工程科学》 2007年第9卷第8期页码 6-14

摘要：

面对催化裂化工艺所遇到的挑战，提出了催化裂化过程反应化学的多维反应结构模式。多维反应结构模式的建立是基于对烃类在酸性催化剂上反应化学认识而进行的知识创新，但多维反应结构不同于烃类在酸性催化剂上反应化学。具有多维反应结构的催化裂化工艺更具有多样性和灵活性，基于此已成功地开发了多产异构烷烃的催化裂化工艺和生产清洁汽油和多产丙烯的催化裂化工艺。

关键词：催化裂化反应化学催化剂多维反应结构两个反应区

HTML PDF 收藏

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

HTML PDF 收藏

Dual-reaction-center catalytic process continues Fenton’s story

Chao Lu, Kanglan Deng, Chun Hu, Lai Lyu

《环境科学与工程前沿（英文）》 2020年第14卷第5期 doi: 10.1007/s11783-020-1261-x

摘要： Abstract • Dual-reaction-center (DRC) system breaks through bottleneck of Fenton reaction. • Utilization of intrinsic electrons of pollutants is realized in DRC system. • DRC catalytic process well continues Fenton’s story. Triggered by global water quality safety issues, the research on wastewater treatment and water purification technology has been greatly developed in recent years. The Fenton technology is particularly powerful due to the rapid attack on pollutants by the generated hydroxyl radicals (•OH). However, both heterogeneous and homogeneous Fenton/Fenton-like technologies follow the classical reaction mechanism, which depends on the oxidation and reduction of the transition metal ions at single sites. So even after a century of development, this reaction still suffers from its inherent bottlenecks in practical application. In recent years, our group has been focusing on studying a novel heterogeneous Fenton catalytic process, and we developed the dual-reaction-center (DRC) system for the first time. In the DRC system, H2O2 and O2 can be efficiently reduced to reactive oxygen species (ROS) in electron-rich centers, while pollutants are captured and oxidized by the electron-deficient centers. The obtained electrons from pollutants are diverted to the electron-rich centers through bonding bridges. This process breaks through the classic Fenton mechanism, and improves the performance and efficiency of pollutant removal in a wide pH range. Here, we provide a brief overview of Fenton’s story and focus on combing the discovery and development of the DRC technology and mechanism in recent years. The construction of the DRC and its performance in the pollutant degradation and interfacial reaction process are described in detail. We look forward to bringing a new perspective to continue Fenton’s story through research and development of DRC technology.

关键词： Dual reaction centers Fenton Pollutant utilization Electron transfer

HTML PDF 收藏

Graphene-reinforced metal-organic frameworks derived cobalt sulfide/carbon nanocomposites as efficient multifunctional electrocatalysts

《化学科学与工程前沿（英文）》 2021年第15卷第6期页码 1487-1499 doi: 10.1007/s11705-021-2085-3

摘要： Developing cost-effective electrocatalysts for oxygen reduction reaction (ORR), oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is vital in energy conversion and storage applications. Herein, we report a simple method for the synthesis of graphene-reinforced CoS/C nanocomposites and the evaluation of their electrocatalytic performance for typical electrocatalytic reactions. Nanocomposites of CoS embedded in N, S co-doped porous carbon and graphene (CoS@C/Graphene) were generated via simultaneous sulfurization and carbonization of one-pot synthesized graphite oxide-ZIF-67 precursors. The obtained CoS@C/Graphene nanocomposites were characterized by X-ray diffraction, Raman spectroscopy, thermogravimetric analysis-mass spectroscopy, scanning electronic microscopy, transmission electronic microscopy, X-ray photoelectron spectroscopy and gas sorption. It is found that CoS nanoparticles homogenously dispersed in the in situ formed N, S co-doped porous carbon/graphene matrix. The CoS@C/10Graphene composite not only shows excellent electrocatalytic activity toward ORR with high onset potential of 0.89 V, four-electron pathway and superior durability of maintaining 98% of current after continuously running for around 5 h, but also exhibits good performance for OER and HER, due to the improved electrical conductivity, increased catalytic active sites and connectivity between the electrocatalytic active CoS and the carbon matrix. This work offers a new approach for the development of novel multifunctional nanocomposites for the next generation of energy conversion and storage applications.

关键词： MOF derivative graphene electrocatalyst oxygen reduction reaction oxygen evolution reaction hydrogen evolution reaction

HTML PDF 收藏

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

HTML PDF 收藏

An overview and recent advances in electrocatalysts for direct seawater splitting

《化学科学与工程前沿（英文）》 2021年第15卷第6期页码 1408-1426 doi: 10.1007/s11705-021-2102-6

摘要： In comparison to pure water, seawater is widely accepted as an unlimited resource. The direct seawater splitting is economical and eco-friendly, but the key challenges in seawater, especially the chlorine-related competing reactions at the anode, seriously hamper its practical application. The development of earth-abundant electrocatalysts toward direct seawater splitting has emerged as a promising strategy. Highly efficient electrocatalysts with improved selectivity and stability are of significance in preventing the interference of side reactions and resisting various impurities. This review first discusses the macroscopic understanding of direct seawater electrolysis and then focuses on the strategies for rational design of electrocatalysts toward direct seawater splitting. The perspectives of improved electrocatalysts to solve emerging challenges and further development of direct seawater splitting are also provided.

关键词： seawater splitting electrocatalysts oxygen evolution reaction hydrogen evolution reaction chlorine chemistry

HTML PDF 收藏

Interface engineering for enhancing electrocatalytic oxygen evolution reaction of CoS/CeO heterostructures

《化学科学与工程前沿（英文）》 2022年第16卷第3期页码 376-383 doi: 10.1007/s11705-021-2062-x

摘要： To realize renewable energy conversion, it is important to develop low-cost and high-efficiency electrocatalyst for oxygen evolution reaction. In this communication, a novel bijunction CoS/CeO₂ electrocatalyst grown on carbon cloth is prepared by the interface engineering. The interface engineering of CoS and CeO₂ facilitates a rapid charge transfer from CeO₂ to CoS. Such an electrocatalyst exhibits outstanding electrocatalytic activity with a low overpotential of 311 mV at 10 mA∙cm⁻² and low Tafel slope of 76.2 mV∙dec^–1, and is superior to that of CoS (372 mV) and CeO₂ (530 mV) counterparts. And it has long-term durability under alkaline media.

关键词： interface engineering CoS/CeO₂ electrodeposition electrocatalyst oxygen evolution reaction

HTML PDF 收藏

Polypyrrole@NiCo hybrid nanotube arrays as high performance electrocatalyst for hydrogen evolution reaction

Shenghua Ye, Gaoren Li

《化学科学与工程前沿（英文）》 2018年第12卷第3期页码 473-480 doi: 10.1007/s11705-018-1724-9

摘要：

The polypyrrole(PPy)@NiCo hybrid nanotube arrays have been successfully fabricated as a high performance electrocatalyst for hydrogen evolution reaction (HER) in alkaline solution. The strong electronic interactions between PPy and NiCo alloy are confirmed by X-ray photoelectron spectroscopy and Raman spectra. Because these interations can remarkably reduce the apparent activation energy (E_a) for HER and enhance the turnover frequency of catalysts, the electrocatalytic performance of PPy@NiCo hybrid nanotube arrays are significantly improved. The electrochemical tests show that the PPy@NiCo hybrid catalysts exhibit a low overpotential of ~186 mV at 10.0 mA·cm⁻² and a small tafel slope of 88.6 mV·deg⁻¹ for HER in the alkaline solution. The PPy@NiCo hybrid nanotubes also exhibit high catalytic activity and high stability for HER.

关键词： NiCo alloy polypyrrole hybrid nanotube electrocatalyst hydrogen evolution reaction

HTML PDF 收藏

cluster-based organic frameworks as highly active electrocatalysts for oxygen reduction and oxygen evolution reaction

《化学科学与工程前沿（英文）》 2023年第17卷第5期页码 570-580 doi: 10.1007/s11705-022-2247-y

摘要： Recently, metal–organic frameworks are one of the potential catalytic materials for electrocatalytic applications. The oxygen reduction reaction and oxygen evolution reaction catalytic activities of heterometallic cluster-based organic frameworks are investigated using density functional theory. Firstly, the catalytic activities of heterometallic clusters are investigated. Among all heterometallic clusters, Fe₂Mn–Mn has a minimum overpotential of 0.35 V for oxygen reduction reaction, and Fe₂Co–Co possesses the smallest overpotential of 0.32 V for oxygen evolution reaction, respectively 100 and 50 mV lower than those of Pt(111) and RuO₂(110) catalysts. The analysis of the potential gap of Fe₂M clusters indicates that Fe₂Mn, Fe₂Co, and Fe₂Ni clusters possess good bifunctional catalytic activity. Additionally, the catalytic activity of Fe₂Mn and Fe₂Co connected through 3,3′,5,5′-azobenzenetetracarboxylate linker to form Fe₂M–PCN–Fe₂M is explored. Compared with Fe₂Mn–PCN–Fe₂Mn, Fe₂Co–PCN–Fe₂Co, and isolated Fe₂M clusters, the mixed-metal Fe₂Co–PCN–Fe₂Mn possesses excellent bifunctional catalytic activity, and the values of potential gap on the Mn and Co sites of Fe₂Co–PCN–Fe₂Mn are 0.69 and 0.70 V, respectively. Furthermore, the analysis of the electron structure indicates that constructing a mixed-metal cluster can efficiently enhance the electronic properties of the catalyst. In conclusion, the mixed-metal cluster strategy provides a new approach to further design and synthesize high-efficiency bifunctional electrocatalysts.

关键词： bimetallic metal–organic frameworks bifunctional electrocatalyst density functional theory oxygen reduction reaction oxygen evolution reaction

HTML PDF 收藏

Polypyrrole@NiCo hybrid nanotube arrays as high performance electrocatalyst for hydrogen evolution reaction

Shenghua Ye, Gaoren Li

《化学科学与工程前沿（英文）》 2019年第13卷第4期页码 845-845 doi: 10.1007/s11705-019-1879-z

HTML PDF 收藏

Kinetics of pozzolanic reaction for preparation of flue gas desulfurizer from fly ash and Ca(OH)2

WANG Jingang, HU Jinbang, WANG Daobin, DUAN Zhenya

《化学科学与工程前沿（英文）》 2007年第1卷第3期页码 266-270 doi: 10.1007/s11705-007-0048-y

摘要： A kinetic model of the pozzolanic reaction for the preparation of flue gas desulfurizers from fly ash and Ca(OH) was deduced on the basis of solid phase reaction kinetic theory. Kinetic expressions and parameters were obtained and verified by experiment. A comparison of calculated results with experimental results showed that precision in kinetic expressions was good. The apparent reaction rate constants of the pozzolanic reaction could be raised by increasing the specific surface area of fly ash and the hydration temperature, and by using a suitable additive.

关键词： comparison calculated pozzolanic reaction precision preparation

HTML PDF 收藏

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

HTML PDF 收藏

Preparation of D-lysine by chemical reaction and microbial asymmetric transformation

LIU Yi, JIAO Qingcai, YIN Xiaoxing

《化学科学与工程前沿（英文）》 2008年第2卷第1期页码 40-43 doi: 10.1007/s11705-008-0023-2

摘要： The DL-lysine crystals from the racemization of L-lysine was treated as substrate with AS1.1009 intact cells as biocatalysts to produce crystalline D-lysine with a yield of 56.6% from the reaction mixture after simple purification. In the presence of 0.10 molar equivalent of salicylaldehyde, L-lysine racemization can be completed within 4 h in 1.0 mol/L of NaOH at 100°C. The activation energy of the processes was 62187.86 J/mol. The characteristics of AS1.1009 decarboxylase were studied. Under the conditions of pH 8.0, temperature 37°C, cell concentration 10 g/L, tween-80 0.5 g/L, substrate concentration 30 g/L, and the specific activity of up to 3840 U, L-lysine can be completely degraded by the decarboxylase for 12 h under the optimal conditions.

关键词： substrate temperature specific activity presence decarboxylase

HTML PDF 收藏

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

HTML PDF 收藏

标题作者时间类型操作

Thermodynamic analysis of reaction pathways and equilibrium yields for catalytic pyrolysis of naphtha

期刊论文

催化裂化过程反应化学的进展

许友好,汪燮卿

期刊论文

Heterogeneous reaction mechanism of gaseous HNO

Nan ZHAO,Qingzhu ZHANG,Wenxing WANG

期刊论文

Dual-reaction-center catalytic process continues Fenton’s story

Chao Lu, Kanglan Deng, Chun Hu, Lai Lyu

期刊论文

Graphene-reinforced metal-organic frameworks derived cobalt sulfide/carbon nanocomposites as efficient multifunctional electrocatalysts

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

An overview and recent advances in electrocatalysts for direct seawater splitting

期刊论文

Interface engineering for enhancing electrocatalytic oxygen evolution reaction of CoS/CeO heterostructures

期刊论文

Polypyrrole@NiCo hybrid nanotube arrays as high performance electrocatalyst for hydrogen evolution reaction

Shenghua Ye, Gaoren Li

期刊论文

cluster-based organic frameworks as highly active electrocatalysts for oxygen reduction and oxygen evolution reaction

期刊论文

Polypyrrole@NiCo hybrid nanotube arrays as high performance electrocatalyst for hydrogen evolution reaction

Shenghua Ye, Gaoren Li

期刊论文

Kinetics of pozzolanic reaction for preparation of flue gas desulfurizer from fly ash and Ca(OH)2

WANG Jingang, HU Jinbang, WANG Daobin, DUAN Zhenya

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

Preparation of D-lysine by chemical reaction and microbial asymmetric transformation

LIU Yi, JIAO Qingcai, YIN Xiaoxing

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

京公网安备 11010502051620号京ICP备11030251号-2

关注我们