Ordered mesoporous materials for water pollution treatment:Adsorption and catalysis

To meet the growing emission of water contaminants,the development of new materials that enhance the efficiency of the water treatment system is urgent.Ordered mesoporous materials provide opportunities in environmental processing applications due to their exceptionally high surface areas,large pore sizes,and enough pore volumes.These properties might enhance the performance of materials concerning adsorption/catalysis capability,durability,and stability.In this review,we enumerate the ordered mesoporous materials as adsorbents/catalysts and their modifications in water pollution treatment from the past decade,including heavy metals(Hg^(2+),Pb^(2+),Cd^(2+),Cr^(6+),etc.),toxic anions(nitrate,phosphate,fluoride,etc.),and organic contaminants(organic dyes,antibiotics,etc.).These contributions demonstrate a deep understanding of the synergistic effect between the incorporated framework and homogeneous active centers.Besides,the challenges and perspectives of the future developments of ordered mesoporous materials in wastewater treatment are proposed.This work provides a theoretical basis and complete summary for the application of ordered mesoporous materials in the removal of contaminants from aqueous solutions.

Effect of Interface Form on Creep Failure and Life of Dissimilar Metal Welds Involving Nickel-Based Weld Metal and Ferritic Base Metal

For dissimilar metal welds(DMWs)involving nickel-based weld metal(WM)and ferritic heat resistant steel base metal(BM)in power plants,there must be an interface between WM and BM,and this interface suffers mechanical and microstructure mismatches and is often the rupture location of premature failure.In this study,a new form of WM/BM interface form,namely double Y-type interface was designed for the DMWs.Creep behaviors and life of DMWs containing double Y-type interface and conventional I-type interface were compared by finite element analysis and creep tests,and creep failure mechanisms were investigated by stress-strain analysis and microstructure characterization.By applying double Y-type interface instead of conventional I-type interface,failure location of DMW could be shifted from the WM/ferritic heat-affected zone(HAZ)interface into the ferritic HAZ or even the ferritic BM,and the failure mode change improved the creep life of DMW.The interface premature failure of I-type interface DMW was related to the coupling effect of microstructure degradation,stress and strain concentrations,and oxide notch on the WM/HAZ interface.The creep failure of double Y-type interface DMW was the result of Type IV fracture due to the creep voids and micro-cracks on fine-grain boundaries in HAZ,which was a result of the matrix softening of HAZ and lack of precipitate pinning at fine-grain boundaries.The double Y-type interface form separated the stress and strain concentrations in DMW from the WM/HAZ interface,preventing the trigger effect of oxide notch on interface failure and inhibiting the interfacial microstructure cracking.It is a novel scheme to prolong creep life and enhance reliability of DMW,by means of optimizing the interface form,decoupling the damage factors from WM/HAZ interface,and then changing the failure mechanism and shifting the failure location.

Cracking on a nickel-based superalloy fabricated by direct energy deposition

Cracks have consistently been a significant challenge limiting the development of additive manufactured nickel-based superalloys.It is essential to investigate the location of cracks and their forming mechanism.This study extensively examines the impact of solidification process,microstructural evolution,and stress concentration on crack initiation during direct energy deposition(DED).The results emphasize that the crack formation is significantly related to large-angle grain boundaries,rapid cooling rates.Cracks caused by large-angle grain boundaries and a fast-cooling rate predominantly appear near the edge of the deposited samples.Liquation cracks are more likely to form near the top of the deposited sample,due to the presence ofγ/γ'eutectics.The secondary dendritic arm and the carbides in the interdendritic regions can obstruct liquid flow during the final stage of solidification,which results in the formation of solidification cracks and voids.This work paves the way to avoid cracks in nickel-based superalloys fabricated by DED,thereby enhancing the performance of superalloys.

Cell-free biocatalysis coupled with photo-catalysis and electro-catalysis: Efficient CO_(2)-to-chemical conversion

The increasing atmospheric carbon dioxide (CO_(2)) concentration has exposed a series of crises in the earth's ecological environment.How to effectively fix and convert carbon dioxide into products with added value has attracted the attention of many researchers.Cell-free enzyme catalytic system coupled with electrical and light have been a promising attempt in the field of biological carbon fixation in recent years.In this review,the research progresses of photoenzyme catalysis,electroenzyme catalysis and photo-electroenzyme catalysis for converting carbon dioxide into chemical products in cell-free systems are systematically summarized.We focus on reviewing and comparing various coupling methods and principles of photoenzyme catalysis and electroenzyme catalysis in cell-free systems,especially the materials used in the construction of the coupling system,and analyze and point out the characteristics and possible problems of different coupling methods.Finally,we discuss the major challenges and prospects of coupling physical signals and cell-free enzymatic catalytic systems in the field of CO_(2) fixation,suggesting possible strategies to improve the carbon sequestration capacity of such systems.

Non-Gaussian quantum states generated via quantum catalysis and their statistical properties

A new kind of non-Gaussian quantum catalyzed state is proposed via multiphoton measurements and two-mode squeezing as an input of thermal state.The characteristics of the generated multiphoton catalysis output state depends on the thermal parameter,catalyzed photon number and squeezing parameter.We then analyze the nonclassical properties by examining the photon number distribution,photocount distribution and partial negativity of the Wigner function.Our findings indicate that nonclassicality can be achieved through the implementation of multiphoton catalysis operations and modulated by the thermal parameter,catalyzed photon number and squeezing parameter.

Recent advances in nickel-based catalysts in eCO_(2)RR for carbon neutrality

The excessive use of nonrenewable energy has brought about serious greenhouse effect.Converting CO_(2) into high-value-added chemicals is undoubtedly the best choice to solve energy problems.Due to the excellent cost-effectiveness and dramatic catalytic performance,nickel-based catalysts have been considered as the most promising candidates for the electrocatalytic CO_(2) reduction reaction(eCO_(2)RR).In this work,the electrocatalytic reduction mechanism of CO_(2) over Ni-based materials is reviewed.The strategies to improve the eCO_(2)RR performance are emphasized.Moreover,the research on Ni-based materials for syngas generation is briefly summarized.Finally,the prospects of nickel-based materials in the eCO_(2)RR are provided with the hope of improving transition-metal-based electrocatalysts for eCO_(2)RR in the future.

Identification of origin of insulating polymer maneuvered photoredox catalysis

Solid non-conjugated polymers have long been regarded as insulators due to deficiency of delocalizedπelectrons along the molecular chain framework.Up to date,origin of insulating polymer regulated charge transfer has not yet been uncovered.In this work,we unleash the root origin of charge transport capability of insulating polymer in photocatalysis.We ascertain that insulating polymer plays crucial roles in fine tuning of electronic structure of transition metal chalcogenides(TMCs),which mainly include altering surface electron density of TMCs for accelerating charge transport kinetics,triggering the generation of defect over TMCs for prolonging carrier lifetime,and acting as hole-trapping mediator for retarding charge recombination.These synergistic roles contribute to the charge transfer of insulating polymer.Our work opens a new vista of utilizing solid insulating polymers for maneuvering charge transfer toward solar energy conversion.

Structure design and electrochemical properties of carbon-based single atom catalysts in energy catalysis:A review

Single atom catalysts(SACs) possessing regulated electronic structure, high atom utilization, and superior catalytic efficiency have been studied in almost all fields in recent years. Carbon-based supporting SACs are becoming popular materials because of their low cost, high electron conductivity, and controllable surface property. At the stage of catalysts preparation, the rational design of active sites is necessary for the substantial improvement of activity of catalysts. To date, the reported design strategies are mainly about synthesis mechanism and synthetic method. The level of understanding of design strategies of carbon-based single atom catalysts is requiring deep to be paved. The design strategies about manufacturing defects and coordination modulation of catalysts are presented. The design strategies are easy to carry out in the process of drawing up preparation routes. The components of carbon-based SACs can be divided into two parts: active site and carbon skeleton. In this review, the manufacture of defects and coordination modulation of two parts are introduced, respectively. The structure features and design strategies from the active sites and carbon skeletons to the overall catalysts are deeply discussed.Then, the structural design of different nano-carbon SACs is introduced systematically. The characterization of active site and carbon skeleton and the detailed mechanism of reaction process are summarized and analyzed. Next, the applications in the field of electrocatalysis for oxygen conversion and hydrogen conversion are illustrated. The relationships between the superior performance and the structure of active sites or carbon skeletons are discussed. Finally, the conclusion of this review and prospects on the abundant space for further promotion in broader fields are depicted. This review highlights the design and preparation thoughts from the parts to the whole. The detailed and systematic discussion will provide useful guidance for design of SACs for readers.

Why the abnormal phenomena of D-band center theory exist?A new BASED theory for surface catalysis and chemistry

Since the D-band center theory was proposed,it has been widely used in the fields of surface chemistry by almost all researchers,due to its easy understanding,convenient operation and relative accuracy.However,with the continuous development of material systems and modification strategies,researchers have gradually found that D-band center theory is usually effective for large metal particle systems,but for small metal particle systems or semiconductors,such as single atom systems,the opposite conclusion to the D-band center theory is often obtained.To solve the issue above,here we propose a bonding and anti-bonding orbitals stable electron intensity difference(BASED)theory for surface chemistry.The newly-proposed BASED theory can not only successfully explain the abnormal phenomena of D-band center theory,but also exhibits a higher accuracy for prediction of adsorption energy and bond length of intermediates on active sites.Importantly,a new phenomenon of the spin transition state in the adsorption process is observed based on the BASED theory,where the active center atom usually yields an unstable high spin transition state to enhance its adsorption capability in the adsorption process of intermediates when their distance is about 2.5Å.In short,the BASED theory can be considered as a general principle to understand catalytic mechanism of intermediates on surfaces.

Cobalt phthalocyanine promoted copper catalysts toward enhanced electro reduction of CO_(2)to C_(2):Synergistic catalysis or tandem catalysis?

The activity and selectivity of electrocatalytic CO_(2)reduction reaction(CO_(2)RR)to C_(2)products on metal catalysts can be regulated by molecular surfactants.However,the mechanism behind it remains elusive and debatable.Herein,copper nanowires(Cu NWs)were fabricated and decorated with cobalt phthalocyanine(CoPc).The electronic interaction between the Cu NWs,CoPc,CO_(2) and CO_(2)RR intermediates were explored by density functional theory(DFT)calculations.It was found that the selectivity and activity of CO_(2)RR towards C_(2)products on Cu NWs were considerably enhanced from 35.2%to 69.9%by surface decoration of CoPc.DFT calculations revealed that CO_(2)RR can proceed in the interphase between Cu substrate and CoPc,and the CO_(2)RR intermediates could synergistically bond with both Cu and Co metal centre in CuNWs-CoPc,which favours the adsorption of CO_(2),CO and CO_(2)RR intermediates,thus reducing the free energy for CO-COcoupling towards C_(2)products.The synergistic interaction was further extended to phthalocyanine(Pc)and other metal phthalocyanine derivatives(MPc),where a relatively weaker synergistic interaction of COintermediates with MPc and Cu substrate and only a slight enhancement of CO_(2)RR towards C_(2) products were observed.This study demonstrates a synergistic catalysis pathway for CO_(2)RR,a novel perspective in interpreting the role of CoPc in enhancing the activity and selectivity of CO_(2)RR on Cu NWs,in contrast to the conventional tandem catalysis mechanism.

Discussion of Misleading on the Interpretation of the Word “Catalysis, Catalyst”

The main idea of this paper is what the resource of the serious error of the widely popular Chemical Reaction Mode catalysis Mechanism-CRMM is. The wrong definition of “catalysis, catalyst” by the catalytic academia boss leads to the wrong interpretation of “catalysis, catalyst” by linguists (Dictionary). The interpretation of “catalysis, catalyst” in a dictionary is misleading. The most fundamental reason for this error is that catalysis experts always believe that catalysts participate in chemical reactions. The result will appear as a series of impossible events. Such as catalysis cyclic reaction, opinions vary intermedium, catalysts repeated decomposition—formation, oxidation-reduction or life and death (enzyme), Sabatier’s principle and Boudart’s principle. The wrong theory leads the research and application of catalysts to the bottomless abyss, and industrial production suffers great losses. Electron Orbital Deformation-Recovere cyclic catalysis Mechanism-EODRM or Electron Cyclic Donate-Adopt catalysis Mechanism-ECDAM shows that the catalytic phenomenon is a physical phenomenon, not a chemical phenomenon, the catalyst does not participate in chemical reactions, only contact is the electron donate-adopt cycle, is the electron orbital deformation recovery cycle Chinese and foreign scholars should change the interpretation on the “catalysis, catalyst”, or add two new words: “contact and contactor”, it is to give up “catalysis, catalyst” altogether.

New paths and research directions in CO_(2) conversion by electro-, photoand plasma catalysis

CO_(2) conversion into value-added products by electro-, photoand plasma catalysis under mild operating conditions(ambient temperature and pressure) is an emerging area to achieve carbon circularity by producing chemicals and fuels using directly renewable energy. Among all CO_(2) conversion approaches, the electrocatalytic reduction of CO_(2) is the most mature technology, capable of achieving high productivity(i.e. high current densities) at large scale, especially for producing carbon monoxide(CO), but with many examples showing selectivity to C_(2) carbon products.

Anomalous yield and intermediate temperature brittleness behaviors of directionally solidified nickel-based superalloy

A nickel-based superalloy with good corrosion resistance was fabricated by directional solidification, and its microstructure and tensile properties at elevated temperatures were investigated. Microstructure observations reveal that the γ＇ precipitates are arrayed in the y matrix regularly with some MC, Ni5Hf and M3B2 particles distributed along the grain boundary. The tensile tests exhibit that the tensile properties depend on temperature significantly and demonstrate obvious anomalous yield and intermediate-temperature brittleness （ITB） behavior. Below 650℃, the yield strength decreases slightly but the ultimate tensile strength almost has no change. When the temperature is between 650 ℃ and 750 ℃, the yield and ultimate tensile strengths rise rapidly, and after then they both decrease gradually with temperature increasing further. The elongation has its minimum value at about 700 ℃. The TEM examination exhibits that sharing of the γ＇ by dislocation is almost the main deformation mechanism at low temperatures, but the γ＇ by-pass dominates the deformation at high temperatures. The transition temperature from shearing to by-pass should be around 800 ℃. The anomalous yield and intermediate-temperature brittleness behaviors should be attributed to the high content of γ＇. In addition, the carbides and eutectic structure also contribute some to the ITB behaviors of the alloy.

Microstructure evolution and deformation features of single crystal nickel-based superalloy containing 4.2% Re during creep

By means of microstructure observation and measurement of creep properties,the high temperature creep behaviors of a single crystal nickel-based superalloy containing Re were investigated.Results show that the single crystal nickel-based superalloy containing 4.2% Re possesses a better creep resistance at high temperature.After being crept up to fracture,the various morphologies are displayed in the different areas of the sample,and the γ＇ phase is transformed into the rafted structure along the direction vertical to the applied stress axis in the regions far from the fracture.But the coarsening and twisting extents of the rafted γ＇ phase increase in the regions near the fracture,which is attributed to the occurrence of the larger plastic deformation.In the later stage of creep,the deformation mechanism of the alloy is that the dislocations with [01^-1]and [011] trace features shear into the rafted γ＇ phase.The main/secondary slipping dislocations are alternately activated to twist the rafted γ＇ phase up to the occurrence of creep fracture,which is thought to be the fracture mechanism of the alloy during creep.

Advances in Application of Non-aqueous Phase Enzymatic Catalysis in Food Additive Production

Non-aqueous phase enzymatic catalysis technology has been widely ap- plied in the area of food additives production. This paper reviewed the types of re- action medium of non-aqueous phase enzymatic catalysis reaction, introduced the application of non-aqueous phase enzymatic catalysis technology in catalysis of L-ascorbic （isoascorbic） acid esters, short-chain acid esters, sugar esters, vitamin A esters, vi- tamin E esters, and other food additives, and finally predicted the prospects of non- aqueous phase enzymatic catalysis technology.

基于Catalysis的面向构件建模方法研究

介绍了基于Catalysis应用面向构件建模方法进行系统分析、设计、建立系统模型的简洁方法。通过对集团型全面预算管理系统的建模过程,给出了该方法的应用细节,将基于构件的软件开发和企业级应用的特点结合起来,给基于分层结构的企业级软件系统的开发以明确的指导。

Nitrogen ligands in two-dimensional covalent organic frameworks for metal catalysis

We introduced bipyridine ligands into a series of two‐dimensional （2D） covalent organic frame‐works （COFs） using 2,2’‐bipyridine‐5,5’‐dicarbaldehyde （2,2’‐BPyDCA） as a component in the mixed building blocks. The framework of the COFs was formed by the linkage of imine groups. The ligand content in the COFs was synthetically tuned by the content of 2,2’‐BPyDCA, and thus the amount of metal, palladium（II） acetate, bonded to the nitrogen ligands could be manipulated. Both the bipyri‐dine ligands and imine groups can coordinate with Pd（II） ions, but the loading position can be var‐ied, with one ligand favoring binding in the space between adjacent COFs’ layers and the other lig‐and favoring binding within the pores of the COFs. The Pd（II）‐loaded COFs exhibited good catalytic activity for the Heck reaction.

Chlorobenzene degradation by electro-heterogeneous catalysis in aqueous solution:intermediates and reaction mechanism

This study was performed to investigate the variables that influence chlorobenzene (CB) degradation in aqueous solution by electro-heterogeneous catalysis.The effects of current density,pH,and electrolyte concentration on CB degradation were determined.The degradation effciency of CB was almost 100% with an initial CB concentration of 50 mg/L,current density 15 mA/cm2,initial pH 10,electrolyte concentration 0.1 mol/L,and temperature 25°C after 90 min of reaction.Under the same conditions,the degradation eff...

Cooperation of nitrogen-doping and catalysis to improve the Li-ion storage performance of lignin-based hard carbon

Hard carbon draws great interests as anode material in lithium ion batteries （LIBs） due to its high the- oretical capacity, high rate capability and abundance of its precursors. Herein we firstly synthesize the lignin-melamine resins by grafting melamine onto lignin. Afterwards, nitrogen doped hard carbon is pre- pared by the pyrolysis of lignin-melamine resins with the aid of catalyst （Ni（NO_3）2·6H_2O） at 1000 ℃. Compared with the samples without nitrogen-doping and catalysis, as-prepared nitrogen doped hard car- bon exhibits higher reversible capacity （345 mAh g-1 at 0.1 A g-1 ）, higher rate capability （145 mAh g-1 at 5 A g-1） and excellent cycling stability. The superior electrochemical performance is ascribed to the synergistic effect of nitrogen doping, graphitic structure and amorphous structure. Among them, nitro- gen doping could create the vacancies around the nitrogen sites, which enhance the reactivity and the electronic conductivity of materials. Additionally, graphitic structure also enhances the electronic con- ductivity of materials, thus improving the electrochemical performance of hard carbon. It is worthwhile that Iignin, renewable and abundant biopolymer, is converted to hard carbon with good electrochemical performance, which realizes the high value utilization of lignin.

Catalysis Conversion Methane into C_(2) Hydrocarbons via Electric Field Enhanced Plasma

In this paper the effect of catalyst and carrier in electric field enhanced plasma on methane conversion into C2 hydrocarbons was investigated. Methane coupling reaction was studied in the system of continuous flow reactor on Ni, MoO3, MnO2 catalysts and different ZSM-5 carriers. The per pass conversion of methane can be as high as 22%, the selectivity of ethylene can be as high as 23.8%, of acetylene 60.8%, of ethane 5.4% and of total C2 hydrocarbons was more than 90%. ZSM-5-25 was the better carrier and MnO2 was the better active component. The efficiency of energy was as high as 7.81%.