Reaction Kinetics Mechanisms and Catalysis
·
2013
·Vol. 110
·期 2
·437-448
·
IF 1.104
Cui Wenjing,Jia Meilin,Ao Wulan,Zhaorigetu Bao
Nano-gold catalysts were prepared by the liquid reduction method and employed in the oxidative esterification of alcohols under ambient conditions. The effects of the supports and gold loading on the catalytic behavior were investigated. The catalysts were characterized by transmission electron microspectroscopy, X-ray diffraction, X-ray photoelectron microspectroscopy and atomic absorption spectrometry. The results indicated that nano-scale metallic state gold was highly dispersed on the support. 95 % methyl benzoate yield was obtained over 3 wt% Au/ZrO 2 catalyst at 30 °C under air atmosphere. Under optimized reaction conditions, benzyl alcohols with electron-withdrawing groups could give high selectivity to the corresponding methyl ester at moderate conversion of alcohols. However, when a benzyl alcohol with electron-donating group was used, high conversion of alcohol but low selectivity of the corresponding methyl ester was obtained. Low yields were obtained with aliphatic alcohols as substrates even at high temperature. The kinetic analysis of the oxidation from benzyl alcohol to benzaldehyde and from benzaldehyde to methyl benzoate was also described. The facile and simple procedure was a great option for direct synthesis of methyl esters from alcohols.
研究领域:
催化化学
·
材料科学
·
有机合成
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2021
·
IF 6.901
Jiankun Wei,Yidan Jing,Zelin Zhao,Zhengwen Fan,Zijia Liang,Junling Huang,Han Wu,Zhizhong Xie,Dan Liu,Deyu Qu,Haolin Tang,Junsheng Li
Electrochemical nitrogen reduction reaction (ENRR) is a promising supplement to the existing Haber-Bosch process due to its mild reaction condition and high theoretical efficiency. However, rational design of efficient ENRR catalyst remains to be the key challenge for the future development of practical ENRR process. In this work, we propose a strategy to enhance the performance of ENRR catalyst by catalyst-support interactions. This strategy is verified with Au/ZrO 2 catalyst. Both experimental and theoretical investigations show that electron is transferred from ZrO 2 substrate to Au. Such an electron transfer process modifies the electronic structure of Au, which enhances the ENRR activity HER performance of the Au active components. Benefiting from the catalyst-support interactions, the optimal Au/ZrO 2 catalyst shows a high ammonia yield of 54.84 μg h −1 mg −1 Au .
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ACS Catalysis
·
2016
·
IF 9.307
Shanhui Zhu,Yanfeng Xue,Jing Guo,Youliang Cen,Jianguo Wang,Weibin Fan
The high-yield synthesis of the biofuel γ-valerolactone (GVL) is a challenging task, which currently stems from the depolymerization of cellulose to levulinic acid, followed by its hydrogenation. We have developed a novel integrated process for the production of GVL from hemicellulose without using liquid acids and external hydrogen. The hemicellulose feed underwent hydrolysis and consecutive dehydration to produce furfural over ZSM-5 catalyst. Subsequently, the formed furfural with 2-propanol performed tandem conversion to GVL over Au/ZrO2 catalyst combined with ZSM-5. This process gave a high yield of GVL under mild conditions: up to 61.5% based on hemicellulose. The outstanding performance was mainly ascribed to the strong interface interaction of Au with ZrO2 species, large amounts of medium-strength acid sites over ZSM-5, and efficient synergy between active metal and acid sites.
研究领域:
生物化学
·
催化化学
✓ 已验证
DOI
高影响因子
ChemSusChem
·
2022
·Vol. 15
·期 13
·e202200092
·
IF 9.14
Xiaohong Hu,Zhijian Li,Haiyong Wang,Haosheng Xin,Song Li,Chenguang Wang,Longlong Ma,Qiying Liu
Graphical Ring-opening : Au/ZrO 2 catalysts with excellent ring-opening hydrogenolysis ability are developed for the selective hydrogenolysis of 5-hydroxymethylfurfural and furfural to produce 2-hexanol and pentanol (1-pentanol and 2-pentanol). The Au-O−Zr interfaces with Lewis acid and metal functionalities play key roles for obtaining the target products with high yield. 2-Hexanol (2-HOL) is a versatile biomass-derived platform molecule for synthesis of liquid transportation fuels, lubricants, or detergents. Herein, a one-step preparation of 2-HOL using 5-hydroxymethylfurfural (HMF) as a substrate was reported for the first time. Several Au-based catalysts supported on different metal oxides were prepared to explore the relationship between carrier and catalytic activity. The results showed that the highest 2-HOL yield of 65.8 % was obtained at complete HMF conversion over the 5 %Au/ZrO 2 catalyst. The 5 %Au/ZrO 2 catalyst exhibited excellent durability after five consecutive recycling runs, while confirming its remarkable ring-opening hydrogenolysis on other biomass-derived furanics, furfural, with a total yield of 1-pentanol and 2-pentanol of 67.4 %. The distinguished ring-opening hydrogenolysis performance of the Au/ZrO 2 catalyst originated from a synergistic effect between the interfacial Au-O-Zr oxygen vacancies-induced Lewis acidic sites (activating C−OH/C=O bonds) and metallic Au (activating H 2 ). This work provides a possibility for producing 2-HOL from HMF with high yield, expanding the sustainable application of lignocellulosic biomass.
研究领域:
催化
·
化学工程
·
可再生能源
·
绿色化学
✓ 已验证
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2021
·
IF 7.46
Qianchun Zhang,Qin Zhou,Shan Tang,Yuxian Zhao,Yuguo Zheng,Li Jiang
Novel sugar-coated haws-sticklike Au/ZrO 2 nanofibers were fabricated by a solvothermal method using a simple precipitation approach. The nanostructure , surface morphology , and elementary composition of the Au/ZrO 2 nanofibers were explored by X-ray diffractometry, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy , N 2 adsorption-desorption isotherms, and energy dispersive spectroscopy . The unique sugar-coated haws sticklike structure with multiple crystal faces (111) as active sites enhanced greatly cataluminescence property for propanal , and the developed propanal sensor based on Au/ZrO 2 nanofibers demonstrated good analytical characteristics with super-fast detection, high sensitivity, and selectivity. The response and recovery time were 1 and 5 s, respectively, the useable linear range was 0.181–38.8 mg/m 3 with a low limit of detection of 0.060 mg/m 3 , and the stability was proved to be fairly excellent for at least 120 days. Besides, the sensor was successfully applied to the analysis of propanal in real samples, and satisfactory recoveries (90.1–109%) with RSDs of 2.6–8.4% were achieved. Moreover, the cataluminescence sensing mechanism was further investigated by density functional theory and GC/MS analysis. The developed methodology has broad application prospects for the detection of propanal at low concentrations.
研究领域:
纳米材料科学
·
分析化学
·
环境监测
✓ 已验证
DOI
高影响因子
JOURNAL OF RAMAN SPECTROSCOPY
·
2022
·Vol. 53
·期 8
·1386-1393
·
IF 2.727
Tong-Jiang Li,Bao-Ying Wen,Yue-Jiao Zhang,Lin Zhang,Jian-Feng Li
Organophosphorus (OPs) compounds have received enormous attention due to high neurotoxicity. However, the complex detection environment makes it very difficult to detect the OPs compounds at extremely low-concentration. Therefore, it is vital to develop a high sensitive analytical method for the detection of low-concentration OPs compounds at complex environment. Here, we proposed a novel surface-enhanced Raman scattering (SERS) substrate based on the core-shell structure Au@ZrO 2 for the detection of extremely low-concentration OPs compounds. By using above SERS substrate, we tested different kinds of OPs compounds and obtained excellent detection results. The detection limit of methyl parathion and triazophos can reach 0.01 mg/kg. Meanwhile, under the actual system (orange peel), the detection limit of the methyl parathion and triazophos also can reach 0.5 and 0.1 mg/kg, respectively. In addition, the above substrate is also very effective for the detection of dimethyl methylphosphonate (DMMP), a simulant for the chemical warfare agent (sarin), and the detection limit can reach 100 mg/kg. Besides, we also verified the reproducibility and stability of Au@ZrO 2 , which showed excellent properties. The relative standard deviation (RSD) of the SERS signal intensity for 20 tests was 6.38% and the enhancement ability of Au@ZrO 2 can remain stable within 30 days. These results show that the proposed Au@ZrO 2 SERS substrate has great potential in the detection of OPs compounds at extremely low-concentration in the complex detection environment.
研究领域:
分析化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2013
·Vol. 109
·期 2
·551-562
·
IF 1.104
Cui Wenjing,Zhu Huaiyong,Jia Meilin,Ao Wulan,Zhang Yulin,Zhaorigetu Bao
Imines were synthesized from benzyl alcohol and amines by using catalysts of gold nanoparticles supported on ZrO 2 (Au/ZrO 2 ). The effects of reaction time, temperature, gold loadings and base were investigated. High yields were achieved under moderate conditions (60 °C) in the presence of KOCH 3 . For instance, the yield of N -benzylidenebenzylamine produced from benzyl alcohol and benzylamine on 3 wt% Au/ZrO 2 is 87 %. The synthesis of imine involves two reaction steps: selective oxidation of benzyl alcohol to benzaldehyde and the coupling reaction of amines with benzaldehyde. In the first step, the base promotes the selective oxidation. The reactions of benzyl alcohol with three different amines, aniline, n -butylamine and benzylamine, were conducted to produce corresponding imines. The results show that the amine with stronger nucleophilicity has better ability to react with benzaldehyde in the second step, resulting in higher yield of the corresponding imine. We proposed a tentative mechanism for the synthesis process.
研究领域:
催化化学
·
有机合成
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2020
·
IF 6.215
Tian Tao,Yang Zhou,Chaohui He,Hanping He,Mingyu Ma,Zhiwei Cai,Nan Gao,Kai Wang,Ruizhi Zhu,Gang Chang,Zhihua Liu,Yunbin He
The excessive use of pesticides does great harm to environment and human health, a high performance sensor is urgently needed for the management of pesticides contamination. Herein, a novel graphene electrochemical transistor (GECT) for the detection of methyl parathion (MP) was successfully fabricated for the first time. A single layer of graphene was covered between the source and drain electrodes by the wet transfer method to act as channel for the transistor. Au-ZrO 2 nanocomposites were electrodeposited at graphene channel of the device, considering the special affinity of ZrO 2 nanoparticles toward phosphate group and electrocatalytic ability of Au nanoparticles. The sensing mechanism was attributed to the change of carrier concentration in channel induced by the electrochemical reaction of MP at the graphene channel, which built up the mathematic relationship between the change of channel current and the concentration of MP. Different modified materials and electrodeposition conditions were compared and optimized. Due to the high carrier mobility of graphene and excellent catalytic performance of Au-ZrO 2 nanocomposites in the channel, the developed sensor showed a limit of detection as low as 0.1 ng/mL and ultra-wide linear range from 0.4 ng/mL to 7 μg/mL, which are comparable or superior to those using the large-scale instruments. Meanwhile, the device exhibited good selectivity toward usual interferents and high accuracy for detection of MP in Chinese cabbage samples, demonstrating the promising practicality of the devices. It is expected that GECT can act as a desirable transducer platform for highly sensitive and selective detection of pesticides.
研究领域:
环境科学
·
分析化学
·
纳米技术
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2019
·
IF 5.256
Nan Gao,Chaohui He,Mingyu Ma,Zhiwei Cai,Yang Zhou,Gang Chang,Xianbao Wang,Yunbin He
For the first time, a simple electrochemical co-deposition was utilized to synthesis the gold and zirconia nanocomposites modified graphene nanosheets on glassy carbon electrode (Au-ZrO 2 -GNs/GCE) for electrocatalytic analysis of methyl parathion (MP). According to Field-Emission Scanning Electron Microscopy (FE-SEM), Transmission Electronic Microscopy (TEM) and X-Ray Diffraction (XRD), the gold nanoparticles were uniformly distributed on the surface of graphene-based nanocomposite. The Au-ZrO 2 -GNs/GCE based sensor exhibited superior capacity for MP detection, ascribed to the strong affinity of zirconia towards the phosphoric group, as well as the high catalytic activity and good conductivity of Au-GNs. The best fabrication and work conditions were then obtained by systematically optimization of the electrodeposition process, pH value and enrichment time. Compared to the gold nanoparticles , zirconia or graphene modified electrodes , Au ZrO 2 -GNs/GCE sensor displayed superior electro-catalytic response toward MP oxidation . The sensor response current of square wave voltammetry was highly linearly correlated with the MP concentrations range of 1–100 ng mL −1 and 100–2400 ng mL −1 with the detection limit of 1 ng mL −1 . The Au-ZrO 2 -GNs/GCE nanocomposite sensor showed excellent accuracy and reproducibility for detection of MP in Chinese cabbage samples, providing a new method for efficient pesticide detection in practical applications.
研究领域:
分析化学
·
纳米技术
·
环境科学
·
电化学
·
传感器
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Zhijian Li,Changhui Zhu,Haiyong Wang,Yuan Liang,Haosheng Xin,Song Li,Xiaohong Hu,Chenguang Wang,Qi Zhang,Qiying Liu,Longlong Ma
For the biomass catalytic valorization in the presence of a H2 atmosphere, large amounts of H2O and H2 are necessary to improve the processing efficiency, which resulted in the waste of such generous inputs. As a model reaction, the traditional hydrodeoxygenation of 5-hydroxymethylfurfural (5-HMF) selectively produces 2,5-dimethylfuran (2,5-DMF) under high pressure H2. Meanwhile, the water-gas shift reaction (WGSR) can counteract the harmful CO by simultaneously producing H2 from H2O. The hydrogenolysis of 5-HMF to 2,5-DMF produces H2O because of the hydroxyl group removal. Therefore, adding a trace amount of H2O to initiate 5-HMF hydrodeoxygenation coupled with WGSR to achieve H2O recycling in the reaction process is of great significance but extremely challenging. Herein, we reported a new process for the selective hydrodeoxygenation of 5-HMF to 2,5-DMF coupled with WGSR using a single catalyst, Au/ZrO2. A detailed study showed that the hydrogen species produced in situ by WGSR was used for 5-HMF hydrodeoxygenation to obtain 78.5% of 2,5-DMF yield. The H/H2O cycle in the coupling reactions exhibited a H2 utilization efficiency of 88.2%. Without using external H2, this work provided a new method for 5-HMF hydrodeoxygenation to 2,5-DMF triggered by WGSR and also showed the potential for application in H2O-saving conversion of cellulosic biomass with C–OH or C═O groups to value-added chemicals and fuels.
研究领域:
生物质催化转化
·
绿色化学
·
可再生资源利用
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry Letters
·
2024
·
IF 4.8
Hongyan Yin,Can Zhang,Quanzhen Zhang,Pu Wang,Jianguo Tang,Sui Mao
Metallic nanoparticles can generate photoexcited hot carriers on the femtosecond scale under light excitation, which holds immense significance for applications such as optical communication and ultrafast imaging. In this study, a tunnelling junction structure with ZrO2 as the dielectric layer is designed and fabricated to achieve efficient hot hole collection between Au nanoparticles and P-type Si. Through characterizations of photoconductive atomic force microscopy, the electrical transition from an ohmic contact to a tunneling junction is confirmed, and the transfer pathway of Au hot holes to P-type Si upon 520 nm excitation is clearly observed. The impact of the tunneling structure on device performance is investigated through the fabrication of Si/ZrO2/Au/TiO2 photodiodes. The performance tests show that hot hole collection by the tunneling effect significantly enhances a range of parameters, e.g., external quantum efficiency by 250%. Noticeably, the external quantum efficiency attributed to photogenerated hot carriers under 520 nm excitation is estimated to exceed 2.5%. Moreover, the transient photoresponse of the photodiodes is examined with a typical rising time of less than 20 ns.
研究领域:
光电子学
·
纳米光子学
·
固态物理
·
材料科学
·
半导体器件
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）