In situ FT-IR study on CO2 hydrogenation over SiO2-supported PtM (M = Cr, Mo, W) complex catalysts

The in situ FT-IR spectra were used to study the CO₂ hydrogenation reaction over the SiO₂-supported heterobinuclear metal complex catalysts, PtM (M=Cr, Mo, W). The bands, which correspond to the formate species absorbed on the catalysts, were observed. During the hydrogenation reactions, the adsorbed linear and bridging CO was not observed. The experimental results suggest that for the CO₂ and CO hydrogenation reaction over the same catalysts, their catalytic active intermediate species and the reaction mechanisms should be different.     

Design and modeling of some sensing and actuating mechanisms for MEMS applications

In this paper, some types of sensing and actuating mechanisms for MEMS applications proposed and designed, the governing equation of models derived and solved with numerical and analytical methods. Results in a good agreement of other works and various parameters which affect on their operation investigated.     

Effects of Mo promoters on the Cu-Fe bimetal catalysts for the DMC formation from CO2 and methanol

The Mo-promoted Cu-Fe bimetal catalysts were prepared and used for the formation of dimethyl carbonate（DMC） from CO₂ and methanol.The catalysts were characterized by X-ray diffraction（XRD）, temperature programmed reduction（TPR）,laser Raman spectra（LRS）,energy dispersive spectroscopy （EDS） and temperature programmed desorption（TPD） techniques.The experimental results demonstrated that the Mo promoters can decrease the reducibility and increase the dispersion of Cu-Fe clusters.The concentration balance of base-acid sites can be readily adjusted by changing the Mo content.The moderate concentration balance of acid and base sites was in favor of the DMC formation. Under optimal experimental conditions,the highest methanol conversion of 6.99%with a DMC selectivity of 87.7%can be obtained when 2.5 wt%of Mo was loaded.     

羊毛—过渡金属络合物的合成及其选择性催化氢化性能的研究

合成和初步表征了以天然高分子羊毛为载体的羊毛一钯单金属和羊毛－钯－铁双金属络合物催化剂；研究表明，在羊毛－钯络合物催化剂中，引入第二金属能极大地改进它的催化性能，提高其催化选择性，更有效的接近酶催化剂的特征．在常温常压下，以羊毛－钯－铁双金属络合物作催化剂，能顺利地使氯代硝基苯和氯代苯甲醛选择氢化成氯代苯胶和氯代苯甲醇．产率均为１００％，有效地抑制了氰取代基的氢解脱除，络合物催化剂中的钯／铁原子比极大地影响着该类氢化反应选择性，在氯代硝基苯和氯代苯甲醛的氢化反应中，最佳的钯／铁原子比分别为１：３和１５：１，这时反应的选择性均达到１００％，溶剂和温度对氢化反应速度均有一定的影响．     

表面有机金属化学(Ⅱ)

简要总结和评述了硅胶表面负载的一些过渡金属氢化物的烷烃碳-碳键和碳-氢键活化、金属铑和铂表面负载的有机锡物种的选择加氢和脱氢及有机金属化合物的沸石分子筛内外表面改性方面的研究进展,指出了今后拟重点研究的一些问题。     

Ultrasonic-assisted preparation and characterization of magnetic ZnFe2O4/g-C3N4 nanomaterial and their applications towards electrocatalytic reduction of 4-nitrophenol

Nanoball-structured ferromagnetic zinc ferrite nanocrystals (ZnFe₂O₄ NPs) entrapped with graphitic-carbon nitride (g-C₃N₄) was produced via straightforward and facile sonochemical synthetical technique (titanium probe; 100 W/cm² and 50 KHz). The morphological (SEM), elemental (EDS), diffraction (XRD), XPS, and electrochemical studies (CV) have been carry out to verify the nanostructure and shape of the materials. The ZnFe₂O₄ NPs/g-C₃N₄ electrode (GCE) was constructed which displayed outstanding electrochemical ability towards toxic 4-nitrophenol (NTP). A sensitive, selective, reproducible, and durable electrochemical NTP sensor was developed by ZnFe₂O₄ NPs/g-C₃N₄ modified electrode. The modified sensor exhibited a high sensitivity and 4.17 nanomolars of LOD. It’s greater than the LOD of previously reported NTP modified sensors. The real-time experiments of the modified electrochemical (ZnFe₂O₄ NPs/g-C₃N₄ electrode) sensor were successfully explained in various water (river and drinking) samples and its showed high standard recoveries. Therefore, sonochemical synthetical method and fabrication of modified electrode were developed this work based on environmental analysis of NTP sensor.     

Electrodynamics of TEM radiation normally incident upon a semi-infinite two-layered metal in the good-conductor approximation

Analytic expressions for power dissipated in each of both metals for the case of a steady-state transverse electromagnetic (TEM) plane wave normally incident upon an arbitrary semi-infinite bimetallic bulk structure in the good-conductor approximation are obtained. Assuming the material parameters are linear in the TEM amplitude, expressions for power dissipation in each metal, as well as the surface impedance of the bimetallic structure are in arbitrarily good agreement with results obtained from a transmission-line analog and Pynting's theorem. The power dissipation for structures with a constant thickness of metal 1 are plotted as a function of the conductivity of metal 1 and are superimposed upon the general phase space domain to self-consistently illustrate the applicability of the continuum approximation used.     

When adding an unreactive metal enhances catalytic activity: NOx decomposition over silver-rhodium bimetallic surfaces

Recent experiments indicate unexpectedly high catalytic activity for decomposition of NO_x species over Ag-Rh nanoparticles, but the crucial role played by the coinage metal remains unclear. We have therefore performed ab-initio density functional calculations aimed at elucidating key features of NO surface chemistry on Ag, Rh, and Rh-Ag alloy substrates. Through investigation of thermochemistry and reaction barriers, and analysis of the alloy density of states, we explain the paradox that addition of an unreactive coinage metal can radically enhance the activity of a transition metal catalyst.     

CeO2负载NiCo双金属催化苯酚液相加氢

采用湿化学浸渍法制备了CeO2纳米棒负载的CoNi双金属催化剂，并研究了其在150 ℃，3 MPa H2下对苯酚加氢成环己醇反应的催化活性，发现具有合适NiCo质量比的NiCo/r-CeO2催化剂显示出比单金属催化剂高的催化活性。通过TEM和XRD证明了NiCo合金的形成和高分散性，H2-TPR和CO2-TPD揭示了合金中钴和镍之间的电子相互作用导致金属与载体之间的相互作用力发生变化， XPS也表明NiCo合金中Ni和Co的电子态也发生了变化。结合表征结果和双金属催化剂催化苯酚加氢反应的活性，表明添加Co可以调节活性部位的表面性能，进而影响NiCo双金属催化剂在苯酚加氢反应中的催化活性。     

High-performance electrocatalyst of vanadium-iron bimetal organic framework arrays on nickel foam for overall water splitting

The development of active,low-cost and durable bifunctional electrocatalysts toward both oxygen evolution reaction(OER) and hydro gen evolution react ion(HER) a re important for overall water splitting.Here,well-defined arrays of vanadium-iron bimetal organic frameworks(VFe-MOF) with controllable stoichiometry have been successfully prepared on nickel foam(NF).The as-fabricated VFe-MOF@NF electrode exhibits excellent electrocatalytic activity and durability for OER and HER in alkaline medium.The material's overpotentials of 10 mA/cm~2 are 246 mV for OER and 147 mV for HER,respectively.The electrolyzer made from the VFe-MOF@NF electrodes as both the cathode and anode in 1 mol/L KOH needs only a voltage of 1.61 V to reach a current density of 10 mA/cm~2.The superior performance of VFeMOF@NF can be attributed to the morphological control and electronic regulation of the bimetals,that is,1) the exposure of the active sites at electrocatalyst/electrolyte interfaces due to the array structure;2)the synergistic effect of vanadium and iron metals on electro-catalyzing the overall water splitting.