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Selective catalytic oxidation of NO over iron and manganese oxides supported on mesoporous silica

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Journal of Natural Gas Chemistry 2008年第3期17卷 273-277页

作者： junfeng Zhang Yan huang Xia Chen Department of Environmental Science and Engineering Xiangtan University Xiangtan 411105 Hunan China

The selective catalytic oxidation （SCO） of NO was studied on a catalyst consisting of iron-manganese oxide supported on mesoporous silica （MPS） with different Mn/Fe ratios. Effects of the amount of manganese and iron, oxygen, and calcination temperature on NO conversion were also investigated. It was found that the Mn-Fe/MPS catalyst with a Mn/Fe molar ratio of 1 showed the highest activity at the calcination temperature of 400 °C. The results showed that over this catalyst, NO conversion reached 70% under the condition of 280 °C and a space velocity of 5000 h-1. SO2 and H2O had no adverse impact on the reaction activity when the SCO reaction temperature was above 240 °C. In addition, the SCO activity was suppressed gradually in the presence of SO2 and H2O below 240 °C, and such an effect was reversible after heating treatment.

关键词： selective catalytic oxidation of NO nitrogen monoxide mesoporous silica iron manganese

Orthorectification of IKONOS and Impact of Different Resolution DEM

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Geo-Spatial Information Science 2006年第2期9卷 108-111页

作者： XU junfeng huang Jingfeng Institute of Agricultural Remote Sensing and Information Technology Zhejiang University Hangzhou 310029China　

IKONOS image has been wildly used in city planning, precision agriculture and emergence response. However, the accuracy of IKONOS Geo product is limited due to distortion caused by terrain relief. Orthorectification was performed to remove the distortion and the impact of different DEM on orthorectification were evaluated. 38 ground control points (GCPs) and 25 independent check points (ICPs) were collected. DEMs were generated from 1∶10 000 and 1∶50 000 topographic maps. Results show that RMS error at the check points is 1.554 0 m using DEM generated from 1∶10 000 topographic map, which can meet the accuracy requirement of IKONOS Precision product (1.9 m RMSE). While RMS error is 2.572 4 m using DEM generated from 1∶50 000 topographic map.

关键词： IKONOS orthorectify DEM

High-performance Refractive Index Sensor Based on Photonic Crystal Single Mode Resonant Micro-cavity

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稀有金属材料与工程 2006年第A3期35卷 425-428页

作者： Shengye huang junfeng Shi Dongsheng Wang Wei Li State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision Instruments and Mechanology Tsinghua University Beijing 100084 China

An effective refractive index sensor built with square lattice photonic crystal is proposed,which can be applicable to photonic integrated *** photonic crystal waveguides rather than conventional ridge waveguides are used as entrance/exit waveguides to the *** layers of photonic lattice are set between the photonic crystal waveguides and the micro-cavity to achieve both a high transmission and a high *** plane wave method is utilized to calculate the disperse curves and the finite difference time domain scheme is employed to simulate the light *** the resonant wavelength of about 1500 nm,the resonant wavelength shifts up by 0.7 nm for each increment of Δn=0.001.A transmission of more than 0.75 is *** the position disorder of the photonic crystal doesn't affect the sensitivity of the sensor, the transmission reduces rapidly as the disorder increases.

关键词： optical biosensor refractive index sensor photonic crystal resonant cavity

Cotton GhMYB7 is predominantly expressed in developing fibers and regulates secondary cell wall biosynthesis in transgenic Arabidopsis

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Science China(Life Sciences) 2016年第2期59卷 194-205页

作者： junfeng huang Feng Chen Siyu Wu Juan Li Wenliang Xu Hubei Key Laboratory of Genetic Regulation and Integrative Biology School of Life Sciences Central China Normal University

The secondary cell wall in mature cotton fibers contains over 90%cellulose with low quantities of xylan and ***,little is known regarding the regulation of secondary cell wall biosynthesis in cotton *** this study,we characterized an R2R3-MYB transcription factor,Gh MYB7,in *** MYB7 is expressed at a high level in developing fibers and encodes a MYB protein that is targeted to the cell nucleus and has transcriptional activation *** expression of Gh MYB7 in Arabidopsis resulted in small,curled,dark green leaves and also led to shorter inflorescence stems.A cross-sectional assay of basal stems revealed that cell wall thickness of vessels and interfascicular fibers was higher in transgenic lines overexpressing Gh MYB7 than in the wild *** expression of Gh MYB7 in Arabidopsis activated the expression of a suite of secondary cell wall biosynthesis-related genes(including some secondary cell wall-associated transcription factors),leading to the ectopic deposition of cellulose and *** ectopic deposition of secondary cell walls may have been initiated before the cessation of cell ***,Gh MYB7 was capable of binding to the promoter regions of At SND1 and At Ces A4,suggesting that Gh MYB7 may function upstream of NAC transcription ***,these findings suggest that Gh MYB7 is a potential transcriptional activator,which may participate in regulating secondary cell wall biosynthesis of cotton fibers.

关键词： cotton (Gossypium hirsutum) fiber development MYB transcription factor secondary cell wall (SCW) biosynthesis ectopic gene expression

Sulfur vacancies-doped Sb_(2)S_(3) nanorods as high-efficient electrocatalysts for dinitrogen fixation under ambient conditions

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Green Energy & Environment 2022年第4期7卷 755-762页

作者： Xuyan Wang Jianwei Bai Yantao Wang Xiaoying Lu Zehua Zou junfeng huang Cailing Xu State Key Laboratory of Applied Organic Chemistry Laboratory of Special Function Materials and Structure Design of the Ministry of EducationCollege of Chemistry and Chemical EngineeringLanzhou UniversityNo.222 Tianshui South RoadLanzhou730000China Lanzhou No.11 Middle School No.523 Pingliang RoadLanzhou730000China

Tuning surface electron transfer process by sulfur(S)-vacancies engineering is an efficient strategy to develop high-efficient catalysts for electroreduction N_(2) reaction(NRR). Herein, the distinct Sb_(2)S_(3) nanorods with S-vacancies(Sv-Sb_(2)S_(3)) have been synthesized by a simple twostep method including hydrothermal and hydrogenation in H_(2)/Ar atmosphere, which shows improved performance for NRR with the NH_(3) yield rate of 10.85 μg h^(-1) mgcat^(-1) at-0.4 V vs. RHE, the faradaic efficiency(FE) of 3.75% at -0.3 V vs. RHE and excellent stability for 24 h, largely outperforming bulk Sb_(2)S_(3). X-ray photoelectron spectroscopy(XPS) and density function theory(DFT) calculations demonstrate that the abundant S-vacancies can create an electron-deficient environment and modulate the electron delocalization in Sv-Sb_(2)S_(3), which can not only facilitate the N_(2) molecule adsorption, but also activate the N≡N, resulting in the enhanced performance for NRR.

关键词： Electrocatalyst N_(2)electroreduction reaction Vacancies Defect engineering

K2HPO4-mediated Photocatalytic H_(2)Production over NiCoP/RP Heterojunction

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Chinese Journal of Structural Chemistry 2022年第6期41卷 62-68页

作者： junfeng huang Chenyang Li Xiaoyun Hu Jun Fan Binran Zhao Enzhou Liu School of Chemical Engineering/Xi'an Key Laboratory of Special Energy Materials Northwest UniversityXi’an 710069China School of Physics Northwest UniversityXi’an 710069China

In this work,bimetallic NiCoP nanoparticles(NPs)were firstly prepared by a solvothermal method using red phosphorus(RP)as P source,and it was combined with RP nanosheets via a physical grinding *** indicates that NiCoP has better charge transfer ability and faster H_(2)releasing kinetics than the corresponding single metal phosphides alone.6 wt%NiCoP/RP exhibits an excellent H_(2)evolution activity in 20 vol.%triethanol-amine/water solution under a 300W Xe-lamp irradiation,and the corresponding H_(2)production rate is 1535.6μmol·g^(-1)·h^(-1),which is 7.4,3.2 and 2.6 times higher than those of pure RP,6 wt%Co_(2)P/RP and 6 wt%Ni_(2)P/RP,*** addition,we demonstrate that K_(2)HPO_(4)can further enhance the H_(2)evolution kinetics by inducing a new H^(+)reduction path,when appropriate K_(2)HPO_(4)is introduced into the reaction *** H_(2)production rate of 6 wt%NiCoP/RP is boosted from 1535.6 to 2793.9μmol·g^(-1)·h^(-1) due to the easier combination between H^(+)and electrons with the assistance of HPO_(4)^(2-).It is 13.4 times higher than that of pure *** work demonstrates that bimetallic phosphides with suitable electrolytes can greatly enhance the photocatalytic H_(2)evolution efficiency.

关键词： photocatalysis hydrogen red phosphorus bimetallic cocatalyst K_(2)HPO_(4)

Catalytic reduction of nitric oxide with carbon monoxide on copper-cobalt oxides supported on nano-titanium dioxide

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Journal of Environmental Sciences 2009年第9期21卷 1296-1301页

作者： CHEN Xia,ZHANG junfeng,huang Yan,TONG Zhiquan,huang Ming Department of Environmental Engineering,Xiangtan University,Xiangtan 411105,China Department of Environmental Engineering Xiangtan University Xiangtan 411105 China

A series of copper-cobalt oxides supported on nano-titanium dioxide were prepared for the reduction of nitric oxide with carbon monoxide and characterized using techniques such as XRD, BET and TPR. Catalyst CuCoOx/TiO2 with Cu/Co molar ratio of 1/2, CuCo total loading of 30% at the calcination temperature of 350℃ formed CuCo204 spinel and had the highest activity. NO conversion reached 98.9% at 200℃. Mechanism of the reduction was also investigated, N20 was mainly yielded below 100℃, while N2 was produced instead at higher temperature. O2 was supposed to accelerate the reaction between NOx and CO for its oxidation of NO to give more easily reduced NO2, but the oxidation of CO by O2 to CO2 decreased the speed of the reaction greatly. Either SO2 or H20 had no adverse impact on the activity of NO reduction; however, in the presence of both SO2 and H20, the catalyst deactivated quickly.

关键词： CuCoOx/TiO2 carbon monoxide nitric oxide catalytic reduction

Selenization triggers deep reconstruction to produce ultrathin γ-NiOOH toward the efficient water oxidation

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Journal of Energy Chemistry 2021年第12期30卷 651-658,I0015页

作者： Kailu Guo Hua Li junfeng huang Yantao Wang Yong Peng Siyu Lu Cailing Xu State Key Laboratory of Applied Organic Chemistry Laboratory of Special Function Materials and Structure Design of the Ministry of EducationCollege of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000GansuChina School of Materials and Energy Lanzhou UniversityLanzhou 730000GansuChina Green Catalysis Center College of ChemistryZhengzhou UniversityZhengzhou 450000HenanChina

Transition metal chalcogenides will be in situ transformed into metal oxyhydroxides during oxygen evolution reaction(OER) process in alkaline ***,most of these compounds only undergo surface reconstruction under operating conditions,which contains a large percentage of inactive atoms in the core,thus limiting the exposure of the active ***,we synthesize a Ni-Mo-Se precatalyst with three-dimensional hierarchical structure and develop a facile on-site electrochemical activation strategy for achieving deep reconstruction of the *** the combination of multiple spectroscopic characterizations and high resolution electron microscopy techniques,we unravel that the Ni-Mo-Se precatalyst is deeply reconstructed into γ-NiOOH with co-leaching of Mo and Se after the anodic *** flower-like γ-NiOOH is constituted by distorted ultrathin nanosheets with a thickness of ~4.5 nm and contains abundant intercalated species such as water and OH^(-)/CO_(3)^(2-) thus offering a large quantity of accessible active *** reach the current density of 10 mA cm^(-2),the derived electrode requires an overpotential of only 244 mV,outperforming almost all the reported *** work highlights the reconstruction chemistry and provides a simple method for the preparation of efficient OER electrocatalyst.

关键词： Electrocatalyst Deep reconstruction NiOOH Ni-Mo-Se Oxygen evolution reaction

An experiment on multibubble sonoluminescence spectra in sodium chloride solution

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Chinese Science Bulletin 2008年第10期53卷 1468-1472页

作者： CHEN Zhan XU junfeng huang Wei CHEN WeiZhong MIAO GuoQing Institute of Acoustics and Key Laboratory of Modern Acoustics of Ministry of Education Nanjing University Nanjing 210093 China

We investigated experimentally the spectra of MBSL in sodium chloride water solution with krypton as dissolved gas. We observed and compared the spectra of hydroxyl ion at 310 nm and that of sodium atom at 589 nm. It has been found that under the same experimental condition, the intensity of sodium atom spectra is obviously higher than that of the hydroxyl ion spectra, and is more sensitive to the experimental condition. The krypton content, the concentration of sodium chloride solution, and the driving sound pressure obviously affect the spectra intensity in certain range.

关键词：气穴现象声致发光光谱氯化钠溶液