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Efficient oxidation of monosaccharides to sugar acids under neutral condition in flow reactors with gold-supported activated carbon catalysts

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Frontiers of Chemical Science and engineering 2024年第9期18卷 113-123页

作者： Ziqin Gong Zengyong Li Xu Zeng Fengxia Yue Wu Lan Chuanfu Liu state key laboratory of pulp and paper engineering School of Light Industry&EngineeringSouth China University of TechnologyGuangzhou 510640China Anhui Provincial engineering center for High Performance Biobased Nylons School of Materials and ChemistryAnhui Agricultural UniversityHefei 230036China

A significant reaction in the synthesis of biomass-based chemicals is the catalyst-based and targeted oxidation of monosaccharides into valuable sugar *** this study,an activated carbon supported gold catalyst was used to oxidize glucose and xylose to gluconic acid and xylonic acid under neutral *** of reaction conditions for the catalysts was performed using both a batch reactor and a flow-through *** a batch reactor,the yields of gluconic and xylonic acid reached 93%and 92%,respectively,at 90°C within 180 *** a flow reactor,both reactions reached a similar yield at 80°C with the weight hourly space velocity of 47.1 h^(-1).The reaction kinetics were explored in the flow *** oxidation of glucose and xylose to gluconic and xylonic acid followed a first-order kinetics and the turnover frequency was 0.195 and 0.161 s^(-1),*** activation energy was evaluated to be 60.58 and 59.30 kJ·mol^(-1),*** study presents an environmentally friendly and feasible method for the selective oxidation of monosaccharides using an activated carbon supported gold catalyst,benefiting the high-value application of carbohydrates.

关键词： monosaccharides oxidation gluconic acid xylonic acid flow reactor kinetics

CFD investigation of structural effects of internal gas intake on powder conveying performance in fuel supply systems for aerospace engines

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Particuology 2024年第9期92卷 140-154页

作者： Guanlong Ren Haijun Sun Fangjun Chen Wen Shen Yunzhen Cai Yihua Xu Henrik Ström Bilainu Oboirien Qingang Xiong School of Aircraft engineering Nanchang Hangkong UniversityNanchang330063China engineering research center of Aero-engine technology for General Aviation Ministry of EducationNanchang330063China state key laboratory of pulp and paper engineering South China University of TechnologyGuangzhou510640China Department of Mechanics and Maritime Sciences Chalmers University of TechnologyGöteborg41296Sweden Department of Chemical engineering University of JohannesburgJohannesburg17011South Africa

Optimal design of gas intake in powder fuel supply systems is crucial for performance of aerospace *** is little research on the impact of intake structure on powder conveying *** novel internal intakes were proposed,which are spherical,cube-shaped,and *** validation,CFD simulations demonstrate that fluctuation of mass flow rate of powders in the dome-shaped intake is reduced by about 73.3%compared with the annular external *** trends of phase velocities are similar for the spherical and cube-shaped intakes,while those are similar for the annular external and dome-shaped internal *** of area of gas zone for the annular external and spherical internal intakes is larger than that for the cube-shaped and dome-shaped internal *** and relative pressure drop in the fluidization chamber have a stable stage,and fluctuation of relative pressure drop is small when dome-shaped internal intake is used.

关键词： Powder supply system Intake structure Dense gas-solid flow Two-fluid model Powder fluidization Pressure drop

Simple-structured hydrophilic sensors for sweat uric acid detection with laser-engraved polyimide electrodes and cellulose paper substrates

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Chinese Chemical Letters 2024年第3期35卷 443-448页

作者： Linhe Xu Xueshan Hu Shuang Zhou Ze Zhang Junxian Zhang Chao Li Daxian Zuo Hao Liu Gang Chen Jiayu Wan Jinsong Tao state key Lab of pulp and paper engineering South China University of TechnologyGuangzhou 510640China Future Battery research center Global Institute of Future TechnologyShanghai Jiao Tong UniversityShanghai 200240China

Accurate detection of uric acid(UA)is crucial for diagnosing gout,yet traditional sweat-based UA sensors continue to face challenges posed by complex and costly electrode fabrication methods,as well as weakly hydrophilic ***,we designed and developed simple,low-cost,and hydrophilic sweat UA detection sensors constructed by carbon electrodes and cellulose paper *** carbon electrodes were made by carbonized polyimide films through a simple,one-step laser engraving *** electrodes are porous,possess a large specific surface area,and are flexible and *** substrates were composed of highly hydrophilic cellulose paper that can effectively collect,store,and transport *** constructed electrodes demonstrate high sensitivity of 0.4μA Lμmol^(-1)cm^(-2),wide linear range of 2–100μmol/*** addition,our electrodes demonstrate high selectivity,excellent reproducibility,high flexibility,and outstanding stability against mechanical bending,temperature variations,and extended storage ***,our sensors have been proven to provide reliable results when detecting UA levels in real sweat and on real human *** envision that these sensors hold enormous potential for use in the prognosis,diagnosis,and treatment of gout.

关键词： Laser-engraved carbon Polyimide Cellulose paper Hydrophilicity Sweat uric acid

Atomically dispersed Mn-N_(x) catalysts derived from Mn-hexamine coordination frameworks for oxygen reduction reaction

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Carbon Energy 2024年第5期6卷 114-126页

作者： Guoyu Zhong Liuyong Zou Xiao Chi Zhen Meng Zehong Chen Tingzhen Li Yongfa Huang Xiaobo Fu Wenbo Liao Shaona Zheng Yongjun Xu Feng Peng Xinwen Peng Guangdong Provincial key laboratory of Distributed Energy Systems School of Chemical Engineering and Energy TechnologyDongguan University of TechnologyDongguanChina state key laboratory of pulp and paper engineering South China University of TechnologyGuangzhouChina Department of Chemistry Centre for Advanced 2D Materials(CA2DM)National University of SingaporeSingaporeSingapore School of Chemistry and Chemical engineering Guangzhou UniversityGuangzhouChina

Metal-organic frameworks recently have been burgeoning and used as precursors to obtain various metal-nitrogen-carbon catalysts for oxygen reduction reaction(ORR).Although rarely studied,Mn-N-C is a promising catalyst for ORR due to its weak Fenton reaction activity and strong graphitization ***,we developed a facile strategy for anchoring the atomically dispersed nitrogen-coordinated single Mn sites on carbon nanosheets(MnNCS)from an Mn-hexamine coordination *** atomically dispersed Mn-N_(4) sites were dispersed on ultrathin carbon nanosheets with a hierarchically porous *** optimized MnNCS displayed an excellent ORR performance in half-cells(0.89 V *** hydrogen electrode(RHE)in base and 0.76 V *** in acid in half-wave potential)and Zn-air batteries(233 mW cm^(−2)in peak power density),along with significantly enhanced *** functional theory calculations further corroborated that the Mn-N_(4)-C(12)site has favorable adsorption of*OH as the rate-determining *** findings demonstrate that the metal-hexamine coordination framework can be used as a model system for the rational design of highly active atomic metal catalysts for energy applications.

关键词： carbon nanosheets electrocatalyst metal-organic frameworks Mn-N_(4) oxygen reduction reaction Zn-air batteries

Bimetallic NiCoP catalysts anchored on phosphorus-doped lignin-based carbon for robust oxygen evolution performance

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Rare Metals 2024年第7期43卷 3084-3095页

作者： Ling-Ying-Zi Xiong Bo-Wen Liu Lei Du Yue-Kuan Zhou Xu-Liang Lin Huan Wang Guangdong engineering technology research center for Sensing Materials&Devices Guangzhou Key Laboratory of Sensing Materials&DevicesSchool of Chemistry and Chemical EngineeringGuangzhou UniversityGuangzhou 510006China School of Chemical engineering and Light Industry Guangdong University of TechnologyGuangzhou 510006China Guangdong Provincial laboratory of Chemistry and Fine Chemical engineering Jieyang center Jieyang 515200China Sustainable Energy and Environment Thrust Function HubThe Hong Kong University of Science and Technology(Guangzhou)Guangzhou 511400China Division of Emerging Interdisciplinary Areas Department of Mechanical and Aerospace EngineeringThe Hong Kong University of Science and TechnologyHong Kong 999077China state key Lab of pulp and paper engineering South China University of TechnologyGuangzhou 510640China

Oxygen evolution reaction(OER)catalysts are the key core materials that determine the performance of fuel cells,metal-air batteries,electrolytic water decomposition,and other *** this work,a green lignin-based non-precious metal OER catalyst was prepared by a simple ***,c arboxylated lignin was used to complex Ni and Co in situ,and then they were placed with sodium hypophosphite in the same tube furnace for upstream and downstream high-temperature calcination to construct a lignin carbon-based Ni-Co bimetallic OER catalyst(NiCoP@C).The synthesized catalyst is a porous bimetallic phosphide with a three-dimensional network structure and high-density electrochemical active ***@C exhibited favorable catalytic activity for the oxygen evolution reaction(OER)with overpotential of 280 mV at 10 mA·cm~(-2)and a Tafel slope of 77 mV·dec~(-1).Additionally,it exhibited remarkable durability during *** functional theory(DFT)calculations revealed that by leveraging the distinctive structure of transition metal phosphide nanoparticles incorporated into a reticulated substrate,the NiCoP@C catalyst offered an increased number of active sites for OER catalysis,significantly enhancing its stability during practical *** present study broadens the utilization pathways of biomass to"turn waste into treasure,"aligning the development concept of green sustainable development.

关键词： Oxygen evolution reaction Lignin Carbon-based catalyst Nickel-cobalt bimetal Metal phosphide

Defect reduction to enhance the mechanical strength of nanocellulose carbon aerogel

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Chinese Chemical Letters 2024年第1期35卷 492-498页

作者： Haihong Lai Zehong Chen Hao Zhuo Yijie Hu Xuan Zhao Jiwang Yi Hongzhi Zheng Ge Shi Yifan Tong Ling Meng Xinwen Peng Linxin Zhong state key laboratory of pulp and paper engineering South China University of TechnologyGuangzhou 510641China Huangpu Hydrogen Energy Innovation center/Guangzhou key laboratory for Clean Energy and Materials School of Chemistry and Chemical EngineeringGuangzhou UniversityGuangzhou 510006China

Carbon aerogels prepared from renewable nano building blocks are rising-star materials and hold great promise in many ***,various defects formed during carbonization at high temperature disfavor the stress transfer and thus the fabrication of flexible carbon aerogel from renewable nano building ***,a structural defect-reducing strategy is proposed by altering the pyrolysis route of cellulose *** salt that inhibits the generation of tar volatilization during pyrolysis can prevent the formation of various structural *** with fewer defects can reduce stress concentration and remarkably enhance the compressibility of carbon aerogel,thus increasing the maximum stress retention of carbon *** carbon aerogel also has high stress sensor sensitivity and excellent temperature coefficient of *** structural defect-reducing strategy will pave a new way to fabricate high-strength carbon materials for various fields.

关键词： Biomass Cellulose nanofiber Pyrolysis Renewable Carbon aerogel

Efficient desorption and reuse of collector from the flotation concentrate:A case study of scheelite

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International Journal of Minerals,Metallurgy and Materials 2024年第11期31卷 2435-2444页

作者： Liming Tao Jianjun Wang Dejin Liao Wenkai Jia Zihan Zhao Wenfang Che Zhongxu Qi Wei Sun Zhiyong Gao School of Minerals Processing and Bioengineering Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral ResourcesEngineering Research Center of Ministry of Education for Carbon Emission Reduction in Metal Resource Exploitation and UtilizationCentral South UniversityChangsha 410083China state key laboratory of Mineral Processing BGRIMM Technology GroupBeijing 102628China Mining technology research center China Tungsten and Hightech Materials Co.Ltd.Chenzhou 423000China Luoyang Luanchuan molybdenum Group Co. Ltd.Luoyang 471500China Changsha Institute of Mining research Co. Ltd.Changsha 410012China

Flotation is the most common method to obtain concentrate through the selective adsorption of collectors on target minerals to make them hydrophobic and *** the hydrometallurgy of concentrate,collectors adsorbed on concentrate can damage ion-exchange resin and increase the chemical oxygen demand(COD)value of *** this work,we proposed a new scheme,i.e.,desorbing the collectors from concentrate in ore dressing plant and reusing them in flotation *** nitrate and benzohydroxamic acid(Pb-BHA)complex is a common collector in scheelite *** this study,different physical(stirring or ultrasonic waves)and chemical(strong acid or alkali environment)methods for facilitating the desorption of Pb-BHA collector from scheelite concentrate were ***-mineral desorption tests showed that under the condition of pulp pH 13 and ultrasonic treatment for 15 min,the highest desorption rates of Pb and BHA from the scheelite concentrate were 90.48%and 63.75%,***-of-mine ore flotation tests revealed that the reuse of desorbed Pb and BHA reduced the collector dosage by 30%for BHA and 25%for *** strong alkali environment broke the chemical bonds between Pb and *** cavitation effect of ultrasonic waves effectively reduced the interaction intensity between Pb-BHA collector and scheelite *** method combining ultrasonic waves and strong alkali environment can effectively desorb the collectors from concentrate and provide“clean”scheelite concentrate for metallurgic plants;the reuse of desorbed collector in flotation flowsheet can reduce reagent cost for ore dressing plants.

关键词： scheelite concentrate collector desorption reuse flotation

research on cigarette during smoking based on reverse engineering and numerical simulation

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Chinese Journal of Chemical engineering 2019年第10期27卷 2359-2375页

作者： Darong Tang JunzhangWu Jinsong Zeng Wenhua Gao Liang Du state key laboratory of pulp and paper engineering Plant Micro/Nano Fiber Research CenterSouth China University of TechnologyGuangzhou 510640China china Tobacco Guangdong Industrial Co.Ltd. Guangzhou 510385China

The three-dimensional(3 D)model of cigarette was accurately constructed through reverse engineering as the research object of numerical *** combustion process of cigarette was studied with computational fluid dynamics(CFD).Standard Laminar models with species transport approach were applied,and numerical simulation of the cigarette was analyzed with semi-implicit method for pressure–velocity *** results showed that the model could predict velocity of cigarette smoke,the distributions of temperature and pressure at different *** order to verify the correctness of model,it was found that the relationship between the velocity of smoke and pressure according to Darcy’s law on z position(x=4 mm,y=0,0 mm≤z≤50.61 mm).

关键词： Cigarette Reverse engineering Computational fluid dynamics

Preparation of lignin/TiO2 nanocomposites and their application in aqueous polyurethane coatings

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Frontiers of Chemical Science and engineering 2019年第1期13卷 59-69,F0004页

作者： Dongjie Yang Shengyu Wang Ruisheng Zhong Weifeng Liu Xueqing Qiu School of Chemistry and Chemical engineering South China University of Technology Guangzhou 510640 China state key laboratory of pulp and paper engineering South China University of Technology Guangzhou 510640 China

A simple method using a water soluble lignin quaternary ammonium salt (LQAS) and TiO2 has been developed for the preparation of lignin/TiO2 nanocomposites in an aqueous medium under mild conditions. The LQAS/TiO2 nanocomposites contain well-dispersed small particles with excellent ultraviolet (UV) shielding abilities and good compatibilities with waterborne polyurethane (WPU). When the LQAS/TiO2 nanocomposites were blended with WPU, the UV absorbance and the tensile ductility of the WPU increased significantly. The composite WPU hybrid film containing 6 wt-% LQAS/TiO2 nanocomposite had the highest visible light transmittance and had excellent ultraviolet aging properties. After 192 h of UV light irradiation, the tensile strength of the composite film was above 8 MPa and the elongation at break was 800%. This work highlights new possibilities for the utilization of alkali lignin.

关键词： lignin TiO2 nanocomposite particle polyurethane film