We investigated ^(50,52-54)Cr-induced fusion reactions for the synthesis of the superheavy element in the 104≤Z≤122 range.The cross sections produced in this investigation using ^(54)Cr projectiles were compared with those obtained in prior experiments.The estimated cross sections from this analysis are consistent with the findings of prior studies.From the current study,the predicted cross section was found to be 42fb at 236 MeV for ^(53)Cr+^(243)Am,23.2 fb at 236 MeV for ^(54)Cr+^(247)Cm,95.6 fb at 240 MeV for ^(53)Cr+248Bk,and 1.33 fb at 242 MeV for ^(53)Cr+250Cf.Consequently,these projected cross sections with excitation energy and beam energy will be useful in future Cr-induced fusion reaction investigations.
Two-dimensional(2D)materials have attracted a great deal of research interest because of their unique electrical,magnetic,optical,mechanical,and catalytic properties for various applications.To date,however,it is still difficult to fabricate most functional oxides as 2D materials unless they have a layered structure.Herein,we report a one-step universal strategy for preparing versatile non-layered oxide nanosheets by directly annealing the mixture of metal nitrate and dimethyl imidazole(2-MI).The 2-MI plays the key role for 2D oxides since 2-MI owns a very low molten point and sublimation temperature,in which its molten liquid can coordinate with metal ions,forming a metal-organic framework,and easily puffing by its gas molecules.A total of 17 materials were prepared by this strategy,including non-layered metal oxide nanosheets as well as metal/metal oxide loaded nitrogen-doped carbon nanosheets.The as-prepared cobalt particle-loaded nitrogen-doped carbon nanosheets(Co@N/C)exhibit remarkable bifunctional oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)electrocatalytic activity and durability.Besides,the Zn-air battery utilizing a Co@N/C catalyst exhibits high power density of 174.3 mW·cm^(-2).This facile strategy opens up a new way for large-scale synthesis of 2D oxides that holds great potential to push 2D oxides for practical applications.
Lignin is the most abundant naturally phenolic biomass,and the synthesis of high-performance renewable fuel from lignin has attracted significant attention.We propose the efficient synthesis of high-density fuels using simulated lignin cracked oil in tandem with hydroalkylation and deoxygenation reactions.First,we investigated the reaction pathway for the hydroalkylation of phenol,which competes with the hydrodeoxygenation form cyclohexane.And then,we investigated the effects of metal catalyst types,the loading amount of metallic,acid dosage,and reactant ratio on the reaction results.The phenol hydroalkylation and hydrodeoxygenation were balanced when 180℃ and 5 MPa H_(2)with the alkanes yield of 95%.By extending the substrate to other lignin-derived phenolics and simulated lignin cracked oil,we obtained the polycyclic alkane fuel with high density of 0.918 g·ml^(-1)and calorific value of41.2 MJ·L^(-1).Besides,the fuel has good low-temperature properties(viscosity of 9.3 mm^(2)·s^(-1)at 20℃ and freezing point below-55℃),which is expected to be used as jet fuel.This work provides a promising way for the easy and green production of high-density fuel directly from real lignin oil.
Metal oxide supported metal catalysts show promising catalytic performance in many industry-relevant reactions.However,the enhancement of performance is often limited by the insufficient metal/metal oxide interface.In this work,we demonstrate a general synthesis of Pt-early transition metal oxide(Pt-MO_(x),M=Ti,Zr,V,and Y)catalysts with rich interfacial sites,which is based on the air-induced surface segregation and oxidation of M in the supported Pt-M alloy catalysts.Systematic characterizations verify the dynamic structural response of Pt-M alloy catalysts to air and the formation of Pt-MO_(x) catalysts with abundant interfacial sites.The prepared Pt-TiO_(x) interfacial catalysts exhibit improved performance in hydrogenation reactions of benzaldehyde,nitrobenzene,styrene,and furfural,as a result of the heterolytic dissociation of H_(2) at Pt-metal oxide interfacial sites.
Glycerol monolaurate(GML)is a widely used industrial chemical with excellent emulsification and antibacterial effect.The direct esterification of glycerol with lauric acid is the main method to synthesize GML.In this work,the kinetic process of direct esterification was systematically studied using p-toluenesulfonic acid as catalyst.A complete kinetic model of consecutive esterification reaction has been established,and the kinetic equation of acid catalysis was deduced.The isomerization reactions of GML and glycerol dilaurate were investigated.It was found that the reaction was an equilibrium reaction and the reaction rate was faster than the esterification reaction.The kinetic equations of the consecutive esterification reaction were obtained by experiments as k_(1)=(276+92261Xcat)exp(-37720/RT)and k_(2)=(80+4413Xcat)exp(-32240/RT).The kinetic results are beneficial to the optimization of operating conditions and reactor design in GML production process.
Ethylene glycol(EG)plays a pivotal role as a primary raw material in the polyester industry,and the syngas-to-EG route has become a significant technical route in production.The carbon monoxide(CO)gas-phase catalytic coupling to synthesize dimethyl oxalate(DMO)is a crucial process in the syngas-to-EG route,whereby the composition of the reactor outlet exerts influence on the ultimate quality of the EG product and the energy consumption during the subsequent separation process.However,measuring product quality in real time or establishing accurate dynamic mechanism models is challenging.To effectively model the DMO synthesis process,this study proposes a hybrid modeling strategy that integrates process mechanisms and data-driven approaches.The CO gas-phase catalytic coupling mechanism model is developed based on intrinsic kinetics and material balance,while a long short-term memory(LSTM)neural network is employed to predict the macroscopic reaction rate by leveraging temporal relationships derived from archived measurements.The proposed model is trained semi-supervised to accommodate limited-label data scenarios,leveraging historical data.By integrating these predictions with the mechanism model,the hybrid modeling approach provides reliable and interpretable forecasts of mass fractions.Empirical investigations unequivocally validate the superiority of the proposed hybrid modeling approach over conventional data-driven models(DDMs)and other hybrid modeling techniques.
Biosynthesizing Au nanoparticles(AuNPs)from gold-bearing scraps provides a sustainable method to meet the urgent demand for AuNPs.However,it remains challenging to efficiently biosynthesize AuNPs of which the diameter is less than 10 nm from a trace amount of Au^(3+)concentration at the level of tens ppm.Here,we constructed an exoelectrogenic cell(eCell)-conductive reduced-graphene-oxide aero-gel(rGA)biohybrid by assembling Shewanella sp.S1(SS1)as living biocatalyst and rGA as conductive ad-sorbent,in which Au^(3+)at trace concentrations would be enriched by the adsorption of rGA and reduced to AuNPs through the extracellular electron transfer(EET)of SS1.To regulate the size of the synthe-sized AuNPs to 10 nm,the strain SS1 was engineered to enhance its EET,resulting in strain RS2(pYYD-P tac-ribADEHC&pHG13-P_(bad)-omcC in SS1).Strain RS2 was further assembled with rGA to construct the RS2-rGA biohybrid,which could synthesize AuNPs with the size of 7.62±2.82 nm from 60 ppm Au^(3+)so-lution.The eCell-rGA biohybrid integrated Au^(3+)adsorption and reduction,which enabled AuNPs biosyn-thesis from a trace amount of Au^(3+).Thus,the required Au^(3+)ions concentration was reduced by one or two orders of magnitude compared with conventional methods of AuNPs biosynthesis.Our work devel-oped an AuNPs size regulation technology via engineering eCell’s EET with synthetic biology methods,providing a feasible approach to synthesize AuNPs with controllable size from trace level of gold ions.
FeOOH have received considerable attention due to their natural abundance and cost-effectiveness.Despite the significant progress achieved,the one-step synthesis of integrated FeOOH is still a major challenge.Meanwhile,the current research on FeOOH catalyst still suffers from the unclear mechanism of controlling morphology.Here,density functional theory(DFT)calculations and X-ray photoelectron spectroscopy(XPS)demonstrated the strong electron-capturing and hydrogen absorption ability of Co in FeOOH,which further promotes the formation and stabilization of FeOOH.We used a one-step electrodeposition method to synthesize Co introduced FeOOH integrated electrocatalyst and propose to introduce ions with different valence states to regulate the morphology of FeOOH by precise modulation of electric double layer(EDL)composition and thickness.The prepared Co-FeOOH-K^(+)has a larger electrochemically active surface area(ECSA)(325 cm^(2))and turnover frequency(TOF)value(0.75 s^(-1)).In the electrochemical experiments of an alkaline anion exchange membrane electrolyzer,Co-FeOOH-K^(+)shows better oxygen evolution performance than commercial RuO_(2) under industrial production conditions and has good industrial application prospects.
Jiaxin LiuYue ShiYanli GuZheng LvLiang ZhaoYu YangTianrong ZhanJianping LaiLei Wang
The electrochemical CO_(2) reduction reaction(CO_(2)RR)has received widespread attention as a promising method for producing sustainable chemicals and mitigating the global warming.Here,we demonstrate a general and facile synthetic route for the metal-nitrogen-carbon(M-N-C)type catalyst by simply calcinating metal acetate and urea with commercial carbon black,which have potential application in CO_(2)RR.The synthesized Ni-NC-600 catalyst has the structure of single Ni atom coordinated with one N atom and three C atoms(Ni-N_(1)C_(3)),which is suggested by X-ray absorption spectroscopy.The Ni-NC-600 catalyst exhibits high CO_(2)RR catalytic performance and a high CO Faraday efficiency above 98%in a wide potential range from-0.7 to-1.3 V(vs.reversible hydrogen electrode(RHE)),superior to most of the reported Ni-N-C catalysts.This work has developed a facile strategy to synthesize high performance CO_(2)RR catalyst.
The rational design of efficient bimetallic nanoparticle(NP)catalysts is challenging due to the lack of theoretical understanding of active components and insights into the mechanisms of a specific reaction.Here,we report the rational design of nanoreactors comprising hollow carbon sphere-confined PtNi bimetallic NPs(PtNi@HCS)as highly efficient catalysts for hydrogen generation via ammonia borane hydrolysis in water.Using both density functional theory calculations and molecular dynamics simulations,the effects of an active PtNi combination and the critical synergistic role of a hollow carbon shell on the molecule diffusion adsorption behaviors are explored.Kinetic isotope effects and theoretical calculations allow the clarification of the mechanism,with oxidative addition of an O-H bond of water to the catalyst surface being the rate-determining step.The remarkable catalytic activity of the PtNi@HCS nanoreactor was also utilized for successful tandem catalytic hydrogenation reactions,using in situ-generated H_(2) from ammonia borane with high efficiency.The concerted design,theoretical calculations,and experimental work presented here shed light on the rational elaboration of efficient nanocatalysts and contribute to the establishment of a circular carbon economy using green hydrogen.
