The precursor NiMoO4 nanorod arrays were prepared on nickel foam by a hydrothermal method using ammonium molydate tetrahydrate [(NH4)6Mo7O24·4H2O] as the Mo source and nickel nitrate hexahydrate [Ni(NO3)2·6H2O] as the Ni source, and subsequently were nitrogenized via a thermal treatment to obtain the NiMoN with rod?like array structure.The phase structure and surface morphology of the catalytic electrode material were characterized by X?ray diffraction (XRD) and scanning electron microscopy (SEM).Besides,the half?reaction oxygen evolution reaction (OER),hydrogen evolution reaction (HER),and overall water electrolysis performance of the material were evaluated by adopting various electrochemical characterizations,including linear scanning voltammetry (LSV),Tafel slope, and electrochemical impedance spectroscopy (EIS).The test results show that the NiMoN?9 catalytic electrode material has both high OER and HER activities.The OER overpotentials for this material to reach 100.00 mA/cm2 are only 293 mV and 340 mV respectively in alkaline fresh water and alkaline simulated seawater,while the corresponding HER overpotentials are 361 mV and 400 mV.In addition,the NiMoN?9 material also exhibits good activities in both water electrolysis and seawater electrolysis with the cell voltages of 2.016 V and 2.032 V respectively to obtain 100.00 mA/cm2 as well as robust stabilities over 55 h.
Hydrocracking is a crucial technology in the refining and petrochemical sectors. It is of great theoretical and practical significance to deeply understand the mechanism of hydrocracking reactions with the aid of reaction kinetics modeling. This paper recounted the research progress in the kinetic modeling of heavy oil distillation and hydrotreating and shows the methods for computing model parameters corresponding to the modeling method and predicting products. The study showed that the reaction kinetics modeling evolved from the decentralized lumped model based on the distillation range from a macroscopic perspective to a continuous lumped model based on production scenarios and then to a complicated microscopic lumped model at the molecular level. In addition, the study compared the advantages and disadvantages of various models in terms of their capacity to reliably predict the composition of products, the intricacy of parameter estimation, rate coefficients, feed dependence, and experimental data required. It also explained the industrial applicability of the lumped model as well as the construction and method for solving molecular hierarchical reaction networks in molecular lumps. Finally, it gives the development prospects of the lumped kinetic model according to the modeling difficulties, the computing power of computers, and the analysis of technology development trends.
This study uses the solvent extraction method to separate and recover aluminum and nickel from the alkali leaching residue of spent hydrogeneration catalysts. It compared and analyzed the extraction efficiency of P204 (Di (2?ethylhexyl) phosphate) and P507 (2?ethylhexylphosphonic acid mono?2?ethylhexyl ester) and investigated the effects of initial pH, the volume fraction of P204, the saponification rate of P204, and the ratio of V(org)/V(aq) on the extraction of aluminum and nickel in the P204 extraction system. The experimental results show that P204 demonstrates better extraction performance than P507 in the separation of aluminum and nickel. Under a concentration of 35% and saponification ratio of 30% of P204, initial pH of 2.75, and V(org)/V(aq) of 3∶1, the extraction rate of aluminum and nickel is 96.45% and 2.77%, respectively. In the two?stage countercurrent extraction process, the extraction rate of aluminum can reach more than 99.50% while that of nickel is below 3.60%. The loaded organic solvent was stripped at 60 ℃ and V(org)/V(aq) =2∶1 for 20 minutes by 6 mol/L HCl solution, and the stripping efficiency of aluminum in the organic phase is 98.04%. Thus, the separation of aluminum and nickel in spent catalysts can be effectively realized.
The effect of hydraulic retention time (HRT) on the performance of a combined packed sequencing batch biofilm reactor (SBBR) for treating simulated domestic wastewater was investigated.The changes of denitrification performance,denitrification rate and EPS in SBBR were detected and analyzed at different HRT (16 h, 12 h and 8 h).The results indicate that HRT has no significant effect on COD removal rate.Shortening HRT inhibited the activity of microorganisms on the biofilm,increased the mass fraction of TB?EPS and LB?EPS by 30.25% and 29.88%,and decreased the denitrification rate to 64.1%.The best HRT obtained from the experiment was 12 h.
Class II?B reservoirs have become the main exploitation target in Daqing Oilfield, and their geological reserves account for 45.8% of the Class II reservoirs.In view of the huge difference in the exploitation of Class II?B reservoirs,a two?phase mathematical model of viscoelastic polymer solution and crude oil was built,and the logarithmic conformation method was used to transform the model.The VOF method was employed to track the two?phase interface in the displacement process,and thus a two?phase numerical model of viscoelastic polymer solution and crude oil was obtained.Moreover,the effects of pore structure and viscoelasticity of polymer on microscopic oil displacement efficiency were studied by the microscopic model of Class II reservoirs. The results demonstrate that higher reservoir heterogeneity is accompanied by lower microscopic oil displacement efficiency,and the oil displacement efficiency of Class II?A reservoirs with better pore parameters is 2.10% higher than that of Class II?B reservoirs.With the increase in viscosity,the microscopic oil displacement efficiency increases,and the oil displacement efficiency of schemes with a viscosity ratio of (viscosity ratio of polymer to crude oil) 1.5
Plasma modification is an effective way to improve the catalytic activities of materials.Firstly,Co2(OH)2CO3 precursor was synthesized by a hydrothermal method.Then,the precursor was subjected to the oxygen atmosphere low?temperature plasma, and the surface modified Co3O4 catalyst (Co3O4?P) was obtained,which was further characterized the XRD,SEM,H2?TPR,O2?TPD,TEM,XPS,FTIR,Raman spectrum and UV?visible spectrum.The results demonstrate that plasma treatment could reduce the average valence state of Co elements in Co3O4 to form more defective sites on the catalyst surface,and lower the Co-O bond energy of Co3O4 to improve its low temperature reduction performance.Under the irradiation of full solar spectrum light with intensity of 776 mW/cm2,reaction space velocity of 30 000 mL/（g·h）and toluene concentration of 500 μg/g，the toluene degradation performance of the Co3O4?P catalyst could reach 100.0%，which was approximately twice that of the Co3O4 catalyst (Co3O4?T) prepared by thermal calcination.
Hydroisomerization reactions are widely adopted in octane upgrading,diesel fuel coagulation reduction and lubricant base oil dewaxing and viscosity reduction.One?dimensional pore zeolites have unique pore?selective effects on straight?chain alkanes,and thus server as the most suitable acidic carrier and active component for isomerization in hydroisomerization reactions. Its isomerization performance is mainly depended on the topologic structure,acid properties and crystal size of zeolite.This paper mainly summarizes the research progress of synthesis,modification and application of one?dimensional pore zeolites with different topologies in recent years as well as the development trend and application prospect of these zeolites for hydroisomerization.
CeO2?X (X is the hydrothermal synthesis time, X=3, 6, 12, 24 h) carriers were prepared by varying the hydrothermal synthesis time using Ce(NO3)3·6H2O and urea as raw materials, and CuO/CeO2?X catalysts were obtained by isovolumetric impregnation with active component Cu, which were applied to methanol steam reforming (MSR) reaction. The effects of hydrothermal synthesis time on the structure and physicochemical properties of the prepared CeO2?X carriers and CuO/CeO2?X catalysts were explored by XRD, BET, H2?TPR.The performances of the CuO/CeO2?X catalyst samples were evaluated in methanol steam reforming(MSR) reaction.The results show that the CuO/CeO2?6 has good catalytic activity. At the reaction temperature of 280 °C, when the molar ratio of water to methanol was 1.2, and the space velocity of methanol vapor (GHSV) was 800 h-1, the methanol conversion rate could reach 92.8%.
Morphology regulation is an important way to improve the performance of electrocatalytic hydrogen evolution reaction. This paper investigated the effect of NiCoP with different dimension on the hydrogen evolution reaction by combining theoretical calculation and experimental analysis methods and constructed structural models of 1D nanowires (NW?NiCoP) and 2D nanosheets (NS?NiCoP).Simulation results show that NW?NiCoP exhibits higher electronic density of electronic states near the Fermi level, which is beneficial to efficient charge transfer. NS?NiCoP features higher hydrogen adsorption energy, which is favorable for the Volmer reaction.NW?NiCoP,NS?NiCoP,and 3D nanosheet?wires (NSW?NiCoP) were prepared by hydrothermal and phosphating processes. Electrochemical tests on NiCoP with different dimension indicate that the overpotential is 45 mV for NSW?NiCoP at -10 mA/cm2.
4?Isobutyloxy?2?cyclohepten?1?one was prepared by the condensation of isobutyryl chloride and 4?hydroxy?2?cyclohepten?1?one.The effects of various amounts of 4?dimethylaminopyridine(DMAP),reaction temperature and reaction time on the esterification reaction were investigated under the condition of no condensation agent.The results show that the optimized reaction condition is 0.3 mmol of DMAP under 25 ℃ for 3 h with a yield of 89%.The results of the NMR show that the synthesized product was the target molecule 4?isobutyloxy?2?cyclohepten?1?one.This esterification reaction features high yields under mild reaction conditions without the involvement of condensation agents,which is in line with the concept of the development of green chemistry.
