Papers by Author: Qian Yu

Abstract: Wood vinegar, as one of the main products of pyrolysis of wood, is very useful, but its system is not stable, easy to produce surface floating oil and precipitation. By test, it was found that 200 mg cetyl trimethyl ammonium bromide (CTMAB) was added to a liter of wood vinegar, and was stirred for 2 hours, wood vinegar surface floating oil and precipitation could be greatly reduced . It would provide useful data for the subsequent development of the wood vinegar.

Abstract: The Pd-based oxidation catalysts on stainless steel wire mesh(SSWM) monolith were prepared by electroless plating method. The effect of two different acid bath (including HNO3-HF and concentrated HCl) on the surface morphology of SSWM substrate and the adhesion of palladium particles with substrate were firstly studied. Then the etched SSWM monoliths were used as support to prepare Pd/SSWM monolith catalysts by electroless plating method and their application in toluene catalytic oxidation was also studied. The results indicated that the optimal palladium loading was 0.3wt% and the calcination temperature was 600°C. And the catalyst etched by HNO3-HF showed better activity in toluene catalytic oxidation and worse adhesion of palladium particles with substrate than that etched by concentrated HCl.

Abstract: Pure wood vinegar is widely used in industry, agriculture and other areas as regulators, but the wood vinegar which produced usually is filled with oil on the surface .The paper mainly study on removing the floating oil on the surface of wood vinegar,choosing the best surfactant called Tween 80 to removing the floating oil and making wood vinegar in a steady system. By this way, it will not appear oil on the surface of wood vinegar for more than half an year, which will broaden the commercial application of wood vinegar

Abstract: Catalytic combustion of toluene on Cu-Mn complex oxides was investigated. The catalysts were prepared by urea-based hydrothermal method and characterized by XRD and SEM. It was found that both the decrease of the Cu/Mn molar ratio and the increase of reaction time contributed to improving catalytic activity for toluene combustion. The temperature for 99% conversion of toluene (T₉₉) was lowered to 210°C. The main crystalline phases of Cu-Mn complex oxides were CuO and Cu_0.45Mn_0.55O₂. It was showed that the existence and high dispersion of Cu-Mn complex oxides were related to the catalytic combustion activity.

Abstract: The styrene-acrylic emulsion modified by the ethylsiloxane as a cross-linking monomer and the hydroxyl phosphate as a flash-rust functional monomer was synthesized. The waterborne anti-corrosion coating film prepared by the styrene-acrylic emulsion exhibits a good overall performance, especially the an excellent corrosion resistance.

Abstract: Catalytic combustion of volatile organic compounds (VOCs) is a high efficient and low-polluted technique. In this paper, the palladium-based combustion catalysts on cordierite honeycomb ceramics (CHC) substrate without interlayer film — Pd/CHC, were prepared by electroless plating method, and the effect of preparing conditions for the catalysts on the catalytic performance of toluene combustion was mainly studied. The optimal conditions were confirmed as follows: plating bath temperature is 60°C, plating time is 30min, palladium salt concentration is 0.2g/L, and calcination temperature after plating is 500°C. Finally, the stability test further indicated that the Pd/CHC catalyst prepared by the optimal electroless plating conditions has good catalytic stability.

Abstract: There are many areas in the world where the ground water has been contaminated by arsenic. One process to purify the water is to use TiO₂ to adsorb the arsenic. As the TiO₂ surface can be cleaned and reused, it has a promising potential as a water purifier. In this paper, the plane-wave function method, based on the density functional theory, has been used to calculate the structures of arsenic(III) on a perfect TiO₂ anatase (1 0 1) surface. All the arsenic(III) solution species such as H₃AsO₃, H₂AsO₃^-1, HAsO₃^-2 and AsO₃^-3 are put onto the surface with many different possible structures to obtain the adsorption energy. Based on the adsorption energy, the bidentate binuclear (BB) adsorption configurations of arsenic(III) on the surface are more favorable at low concentrations, whereas BB form and monodentate mononuclear (MM) form may coexist at higher concentrations. The models and results fit well with published experimental results. The results and conclusions will be of benefit to further research on arsenite adsorption and its photocatalytic oxidation on a TiO₂ surface.

Abstract: The palladium-based combustion catalysts on cordierite honeycomb ceramics (CHC) substrate without interlayer film (Pd/CHC) were prepared by electroless plating method. By means of scanning electron microscopy (SEM) and BET specific surface area, it was found that the palladium phases on the prepared catalyst after calcination treatment at 500°C were well dispersed on substrate with small and uniform particles. The X-ray diffraction, energy dispersion X-rays (EDX) analysis, adherence test and temperature programmed reduction (H₂-TPR) analysis further indicated that the palladium phase had good adherence strength on the surface of CHC substrate and the moderate ratio of metallic Pd and PdO phase was only obtained on the catalyst calcined at 500°C . Moreover, the results of activity tests for toluene combustion showed that the 0.24%Pd/CHC catalyst had good low temperature catalytic activity and temperature-resistance property. The total combustion temperature (T₉₀) for toluene over catalyst calcined at 300, 500 and 900°C was at 239, 225 and 233°C respectively. And the toluene conversion could keep up above 97% during the stability test of Pd/CHC catalyst at 230°C for 105 h, indicating the good catalytic stability of the prepared catalyst.

Abstract: The palladium based combustion catalysts on FeCrAl alloy substrate (Pd/FeCrAl) were prepared by electroless plating method. By means of scanning electron microscopy (SEM), X-ray diffraction and BET specific surface area, it was found that the prepared catalyst after calcination treatment at 800°C could obtain utmost PdO phases, which were well dispersed on substrate with small and uniform particles. The EDX analysis and the adherence tests further indicated that a synergistic interaction was formed between palladium components and substrate on catalyst calcined above 600°C, which might be caused by α-alumina whiskers packaging palladium particles on the surface of substrate. Moreover, the results of activity tests for toluene combustion showed that the 0.1%Pd/FeCrAl catalyst had good low temperature catalytic activity and temperature-resistance property. The total combustion temperature (T90) for toluene over catalyst calcined at 600, 800 and 1000°C was at 218, 207 and 217°C respectively. And the toluene conversion could keep up above 99% during the stability test of Pd/FeCrAl catalyst at 210°Cfor 50 h, indicating the good catalytic stability of Pd/FeCrAl catalyst.

Abstract: Reverse micro emulsion method showed some advantages in the preparation of the catalyst MnBaAl11O19-δ with large surface area and high activity, when compared with sol-gel method or co-precipitation method. The influences of water content in reverse micro emulsion on nanostructure catalyst MnBaAl11O19-δ were discussed in this paper. The catalyst MnBaAl11O19-δ was prepared by reverse microemulsion method with a system consisted of 55% of n-heptane, 15% of emulsifier OP-10, 15% of 1-octanol and 15% of water (volume ratio). It resulted in the catalyst a length of 10-30nm plated-like phase and large surface area of 106 m2/g. The catalyst was applied in dimethyl ether combustion and it showed high activity with T10% at 160 °C and T90% at 300 °C. The recycle reverse micro emulsion was reused to prepare the catalyst MnBaAl11O19-δ. The catalyst MnBaAl11O19-δ prepared with that, still showed large surface area of 65m2/g and high activity with T10% at 170 °C and T90% at 320 °C in dimethyl ether catalytic combustion.