查看更多>>摘要：Here,a simple method is used for the preparation of calcium alginate-activated carbon composite beads(Alg-ACBDs).These beads were introduced into different metal salt solutions for decoration with single metal nanoparticle(M°)and double metal nanoparticles(M~0-M~0).The prepared M~0/Alg-ACBDs catalysts,such as,Cu~0/Alg-ACBDs,Ag°/Alg-ACBDs,Fe~0/Alg-ACBDs,Cu~0-Ag~0/Alg-ACBDs,and Fe~0-Cu~0/Alg-ACBDs were evaluated against NaBH4 methanolysis.In addition,different surfactants,such as,brij-56,pluronic F-127,and urea(Co(NH2)2),different amount of NaBH4,catalyst,and temperature effect was also investigated for higher H2 generation from NaBH4 methanolysis.Similarly,the synthesized catalysts were used for the reduction of different nitrophenols(NPs)and dyes.The Fe°-Cu°/Alg-ACBDs catalyst efficiently catalyzed the reduction reaction of 4-NP and methyl orange(MO)and both were studied in detail.The corresponding reduction rate of 4-NP and MO was observed as 1.829 and 1.163 min-1,respectively.Moreover,the recyclability of the catalyst was investigated for 4-NP and H2 generation,where no decrease in the reduction percentage of 4-NP was recorded,while reduction in their catalytic rates was observed.
查看更多>>摘要：Alzheimer's disease(AD),as a neurodegenerative disease,has become a major disease threatening the physical and mental health of the elderly.In order to find potential cost-effective and valuable AD biomarkers from human serum,we developed and designed a post-modified functional nanomaterial denoted as H-CeO2@PEI-Ti with a porous hollow structure modified with polyethyleneimine(PEI)and Ti~(4+).This post-modified porous hollow nanomaterial integrated multiple enrichment strategies,including immobilized metal ion affinity chromatography(IMAC)and metal oxide affinity chromatography(MOAC)with electrostatic interaction synergy and hydrogen bond assistance was applied to the phosphoproteomics for the first time.The experimental results demonstrated good performance in the enrichment of standard phosphoprotein tryptic digests,such as extremely low detection limit(0.02 fmol),excellent selectivity(1:5000 M ratio of p-casein and BSA),given that the large specific surface area created by the special porous hollow structure.In serum analyses,49 phosphopeptides corresponding to 31 phosphoproteins were identified in the serum of the normal controls,and 49 phosphopeptides corresponding to 32 phosphoproteins in AD patients.More importantly,some functional items based on Gene Ontology(GO)analysis after enrichment for human serum supported the molecular biological processes that may be related to the pathogenesis of AD,including copper ion binding,heparin binding and retinoid metabolism.
查看更多>>摘要：In this work,Pt-NixOy heteroaggragate nanoparticles confined in hollow mesoporous silica nanospheres(Pt-NixOy@HMSNs)are synthesized in one-pot,which features Pt-NixOy hybrid nanoparticles inside hollow cavities of mesoporous silica nanospheres.Through adjusting the ratios of Pt~(2+)/Ni~(2+)in micelles,Pt-NixOy@HMSNs with different Pt/Ni ratios are synthesized.The obtained materials were tested for hydrolysis of ammonia borane with detailed kinetic studies.Compared to Pt@HMSNs and Ni@HMSNs,Pt4-(NixOy)_(1/x)@HMSNs show the enhanced performance in AB hydrolysis.The catalytic activity improvement is ascribed to the synergistic effect of Pt-NixOy and the void confinement,where the interfaces of Pt-NixOy greatly enhance the hydrolysis activity and the confinement of functional nanoparticles inside the central voids increases their structural and catalytic stability.
查看更多>>摘要：Herein,a bifunctional self-pillared MFI nanosheets zeolite(Sn-B-SPP)is designed to achieve the highly selective conversion of sucrose to fructose,which is significant for utilization of the nature abundant sucrose.This Sn-and B-containing SPP zeolite was prepared through a facile solid-state ion exchange approach based on a B-SPP,which overcomes the difficulty of direct nucleation.Sn-B-SPP possesses the structural advantages of ultra-thin intergrown nanosheets materials such as high external surface area,extremely short diffusion length and highly exposed active sites,which are conducive for the conversion of bulky substrates.Meanwhile,the concerted Lewis acidity and weak Br0nsted acidity are essential for the sucrose conversion in alcohol,achieving a 77.0% fructose yield in 4 h after hydrolysis,far surpassing the performance of its microporous analogue and conventional hierarchical Sn-B-MFI.
查看更多>>摘要：Pure and compact zeolite SSZ-13 membrane with excellent dehydration performance was obtained with organ structure-directing agent(OSDA)free synthesis method.The seed precursor on the support affected the phas morphology and compactness of the obtained membranes.Without the usage of the seed,GIS membrane wi notable cracks were formed.Compared to the seed of H-SSZ-13,the crystallization rate of SSZ-13 crystal w,faster with the NH4-SSZ-13 seed.And the crystallinity of SSZ-13 crystal prepared with NH4-SSZ-13 seed w; obviously higher than that prepared with H-SSZ-13.In addition,the pure zeolite SSZ-13 can be obtained wi NH4-SSZ-13 seed,while GIS impurities and SSZ-13 co-existed in the product prepared with H-SSZ-13 see indicating that NH4-SSZ-13 seed showed higher inductive effect than H-SSZ-13 seed on the formation of SSZ-1 crystal.Thus,pure and compact SSZ-13 membrane can be synthesized with NH4-SSZ-13 seed.The characte ization results showed that the SSZ-13 membrane was obtained via dissolution-recrystallization rout Furthermore,the synthesis parameters of zeolite SSZ-13 membrane by OSDA free method were optimized sy tematically.The results revealed that synthesis temperature,time and the synthesis gel component would affe the morphology,phase and compactness of the obtained membrane.The SSZ-13 membrane with the optim conditions showed good reproducibility and a relatively high pervaporation dehydration performance,tl average water in permeate was 99.9%,and the average water flux was 1.82 kg/m~2-h,implying that pure zeoli SSZ-13 membrane,which was obtained by OSDA free method with optimum synthesis parameters,showed potential application value towards pervaporation dehydration process.
查看更多>>摘要：MFI metallosilicates AlMFI and FeMFI were prepared by hydrothermal synthesis,and Zn species were introduced into these MFI-type zeolites by ion exchange.Acetone-to-aromatics(ATA)reactions were carried out using the MFI-type zeolites before and after Zn ion exchange treatment.We examined the effects of zeolite Br0nsted acid strength,Zn species,and Zn dose on(1)selective production of benzene-toluene-xylene(BTX)from acetone,and(2)catalyst lifetime.AlMFI selectively produced BTX due to its strong Br0nsted acidity,and the introduction of Zn further enhanced its BTX selectivity.In contrast,FeMFI showed high selectivity for light olefins even after Zn ion exchange treatment.Increasing the Zn dose added to AlMFI did not improve its BTX selectivity but did suppress the catalytic deactivation rate.Together,the effects of Zn addition and AlMFI's strong Br0nsted acidity resulted in highly selective BTX production and long catalyst lifetimes in the ATA reaction.
查看更多>>摘要：Several different types of seeds have been introduced into the organic template-free synthesis of zeolite ECR-1.The corresponding crystallization process was affected by the structural properties of added seeds.A radicalized seeds-assist route for the rapid synthesis of zeolite ECR-1 in the absence of organic templates is demonstrated.The radicalized zeolite ECR-1 seeds can accelerate the induction and growth period of crystallization simultaneously.The crystalized zeolite ECR-1 products were characterized by X-ray diffraction,scanning electron microscopy,X-ray fluorescence,nitrogen adsorption-desorption and temperature-programmed desorption of ammonia.Compared with those synthesized in the presence of normal seeds,the zeolite ECR-1 products obtained via radicalized seeds-assist route exhibited higher crystallinity,consumed shorter crystallization time and presented a better catalytic performance in iso-butane cracking reaction.
查看更多>>摘要：The photocalalytic activity of four mesoporous RE metal(Ce~(3+),La~(3+),Sm~(3+),Dy~(3+))doped titania was compared and investigated under UVA and visible light irradiation.The photocatalysts were synthesized by using a template guided sol-gel method and were fully characterized by XRD,FTIR,UV-Vis,TEM and Nitrogen adsorption-desorption techniques.The presence of the dopant in the mesoporous RE metal doped titania samples has been demonstrated by FTIR,XPS and EDX techniques.The results confirm that the doping of titania particles with rare earth metals could be achieved and the doping process do not change the crystalline phase of TiO2.The pho-tocatalytic activity decreases in the following order:Sm-TiO2>Dy-TiO2>La-TiO2>Ce-TiO2.Moreover,quenching experiments were carried out to further disclose the contribution of involved ROS in the process.
查看更多>>摘要：A new type of hierarchical porous carbon with tri-modal pore structure(Tri-PC),i.e.,ordered micropores(1.3 nm),uniformly distributed mesopores(2-10 nm)and"earthworm-shaped"mesochannels(with a diameter of 20 nm)running through the whole particle was successfully realized via a novel and facile template approach,in which zeolite Y was firstly gone through a pore expansion using oxalic acid-ammonium fluoride mixture to prepare hierarchical porous zeolite.The hierarchical porous zeolite was subsequently used as the template to catalytically grow carbon via CVD technique.Tri-PC was then obtained after the removal of the template.The as synthesized Tri-PC showed great potential as the catalyst support.We evaluated the ORR catalytic activity of Tri-PC supported platinum nanoparticles(Pt/Tri-PC)in alkaline electrolyte,which exhibits 20 mV higher onset potential(0.95 V)and 30 mV higher half-wave potential(0.87 V)than commercial 10 wt% Pt/C catalyst.Meanwhile,the electrochemical impedance spectroscopy measurement showed that Pt/Tri-PC had lower charge transfer resistance.High performance benefits from a collaborative hierarchical architecture.Micropores offer a large specific surface area and sufficient active sites,mesopores increase the accessibility of active sites and shorten the diffusion path of fuels and products,and mesochannels further enhance the connectivity of the entire pore network.The present work highlights the significance of the hierarchical porous structure for enhancing the catalytic performance of catalysts and suggests that Tri-PC could be used as an advanced catalyst support in many fields.
查看更多>>摘要：The gold recovery from wastewater is not only beneficial to environmental protection,but also to alleviate the shortage of resources.Chitosan is considered as an excellent adsorption material,but its application in gold recovery is always some shortcomings including low adsorption capacity and selectivity.This work developed an efficient biosorbent(CS-ES)by functionalizing chitosan with poly(ethylene sulfide)for gold recovery from simulated wastewater.The properties and adsorption mechanism of CS-ES were investigated using SEM,EDS,XRD,FT-IR,BET and XPS.The results of experiments revealed that the adsorption efficiency of CS-ES for Au(III)reaches more than 90% in a wide pH range(2.0-6.0)and the highest adsorption efficiency about 99.07% was achieved at pH = 5.0.At 318 K,the highest adsorption ability of CS-ES for gold ions was 657.49 mg/g.The adsorption findings supported the Langmuir and pseudo-second-order models,suggesting that monolayer chemisorption is the dominant adsorption mechanism.The thermodynamic performance(AH° and AS°>0,AG°<0)showed that gold ion adsorption by CS-ES is spontaneous exothermic reaction.CS-ES shows an excellent reproducibility after four adsorption-desorption cycles and selectivity against six metal ions.Moreover,a variety of physicochemical and spectroscopic tests demonstrate the extremely effective adsorption and in-situ reduction of gold by CS-ES are based on electrostatic attraction,chelation,and reduction between gold and nitrogen/sulfur groups.In this work,a novel adsorbent for recovering Au(III)from wastewater was devised with great efficiency,selectivity and repeatability.
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