Zhu J.-F.,University of Sichuan |
Zhu J.-F.,Kunming Sino Platinum Metals Catalyst Co. |
Tao G.-H.,University of Sichuan |
Liu H.-Y.,University of Sichuan |
And 3 more authors.
Green Chemistry | Year: 2014
The water-soluble metal nanoparticles (NPs) stabilized by poly(N-vinyl-2-pyrrolidone) (PVP) were prepared and examined as catalysts for the one-step selective hydrogenation of phenol to cyclohexanone in water. More than 99% conversion of phenol and selectivity to cyclohexanone was obtained at 90 °C and 1 atm H2 for 16 h over "soluble" Pd NPs that were reduced by NaBH4 and stabilized by PVP. These Pd NPs were stable, and no leaching or aggregation was detected after five successive runs, showing their advantage for catalyzing the efficient synthesis of cyclohexanone via the one-step selective hydrogenation of phenol under mild conditions. © the Partner Organisations 2014.
Wang M.,Kunming University of Science and Technology |
Liao B.,Kunming University of Science and Technology |
Liu Y.,Yunnan University |
Wang S.,Kunming University of Science and Technology |
And 2 more authors.
Applied Thermal Engineering | Year: 2016
In this paper, a comprehensive computational fluid dynamics (CFD) methodology was adopted to investigate the characteristics of oxy-coal combustion in a cement kiln with a specially designed burner. The simulation was conducted under five oxidant stream conditions with different O2/N2 volume ratios: 21/79, 24/76, 27/73, 30/70, and 33/67. The results revealed that there is strong entrainment from the primary air to the secondary air, resulting in an inner recirculation zone and outside recirculation zone. The oxygen-enriched combustion increases the maximum temperature and improves the combustion efficiency; however, the uniformity of the temperature field becomes worse. The temperature rises sharply as the oxygen content increases; however, the enhancement is slight when the oxygen content exceeds 30%. At a lower oxygen content (<27%), the NOx emissions increase slowly as the oxygen content increases, whereas NOx increases sharply when the oxygen content exceeds 27% in volume. This suggests that the optimal oxygen content is no more than 27% for pulverized coal combustion in a cement kiln. The simulation results reasonably agree with the measured data. The findings of this work will help save fuel consumption and decrease production cost. © 2016 Elsevier Ltd. All rights reserved.
Zhang Y.,Kunming University of Science and Technology |
Zhang Y.,Kunming Sino Platinum Metals Catalyst Co. |
Wang K.,Kunming University of Science and Technology |
Hu J.,Kunming University of Science and Technology
Key Engineering Materials | Year: 2012
Zirconia precursor was prepared by an alcohol-aqueous coprecipitation process from raw materials of ZrOC12·8H2O and ammonia, the zirconia powders were subsequently obtained by calcination of the precursor at 600°C and ball milling. The properties of zirconia powder prepared by alcohol-aqueous method after ball-milling had been researched by BET, XRD, TEM and laser granularity instrument. The results show that by using ball-milling the agglomerate size can be effectively decreased but the primary particle size is hardly affected. The surface area of powder after calcinated can be markedly increased and narrowed size distribution can be gained by ball-milling, but the phase structure of the powder had not been changed. © (2013) Trans Tech Publications.
Yang D.-X.,Kunming University of Science and Technology |
Yang D.-X.,Kunming Sino Platinum Metals Catalyst Co. |
Ning P.,Kunming University of Science and Technology |
He J.-L.,Kunming Sino Platinum Metals Catalyst Co. |
And 3 more authors.
Key Engineering Materials | Year: 2014
The Ce0.5Zr0.5O2 nanocomposites (CZ) were prepared by co-precipitation(CP), fractional precipitation (FP) and fractional precipitation with hydrothermal treatment (FP-HT). The samples were characterized by X-ray diffraction (XRD), Brunauer-Emmet Teller method (BET), H2-temperature programmed reduction (H2-TPR), and thermogravimetric analysis (TG) under H2-N2. XRD results displayed that all samples formed a single solid solution-like ceria-zirconia phase. BET results revealed CZ prepared by FP-HT (CZ-FP-HT) had the highest surface area. H2-TPR and TG analysis under H2-N2 showed CZ-FP-HT exhibited the strongest redox ability and oxygen storage capacity. Moreover, the catalytic activity of Pd supported on CZs for CH compounds were studied. The fresh and aged Pd/CZ-FP-HT catalyst all showed a lower light-off temperature and full-conversion temperture than Pd/CZ-CP and Pd/CZ-FP catalysts. © (2015) Trans Tech Publications, Switzerland.
Gu Y.W.,Kunming University of Science and Technology |
Gu Y.W.,Kunming Sino Platinum Metals Catalyst Co. |
Zhang H.Y.,Kunming University of Science and Technology |
Liu F.,Kunming Sino Platinum Metals Catalyst Co. |
Li Y.Y.,Kunming Sino Platinum Metals Catalyst Co.
Materials Research Innovations | Year: 2015
Activated carbon was modified with γ-Al2O3 by the impregnation precipitation method, and the obtained Al2O3-AC was characterised by a surface area and pore size analyser, transmission electron microscopy and X-ray diffraction analyser. The results suggested that the content of γ-Al2O3 on the carbon surface was an important factor for the specific surface area. Transmission electron microscopy and X-ray diffraction analysis indicated that with an increase of the content of γ-Al2O3, more γ-Al2O3 wires or bars could be observed. Rosin disproportionation reaction revealed that the Pd catalyst prepared with Al2O3-AC as support had higher catalytic activity than that using the original carbon. With an increase in the content of γ-Al2O3, the maximum catalytic activity was achieved when the γ-Al2O3 content increased to 10wt-%, while the catalytic activity basically remained unchanged when the content of γ-Al2O3 varied from 10 to 15 wt-%. © W. S. Maney & Son Ltd 2015.
Liu Y.Q.,Kunming University of Science and Technology |
Liu Y.Q.,Yunnan University |
Zhang A.M.,Kunming Sino platinum Metals Catalyst Co. |
Qing S.,Kunming University of Science and Technology |
And 3 more authors.
IOP Conference Series: Materials Science and Engineering | Year: 2015
With the intensification of the global energy crisis, the production cost of enterprises is continuously increasing because of the rising fuel prices and high requirements for environmental protection. As result, energy savings and environmental protection are vital considerations for a variety of enterprises. As a practical energy-saving technology, oxygen-enriched combustion has played a major role in energy saving and emissions reduction as its application in industrial furnaces has been popularized in recent years. This experiment was conducted in a cement rotary kiln with a capacity of 4000 t/d in a factory in China. Based on measured data in the oxygen-enriched combustion experiment, we determined the patterns of variation in the main parameters of the cement rotary kiln under oxygen-enriched production conditions. The results provide important theoretical and practical base for the cement building materials industry in energy saving and emissions reduction.
Zhang Z.,Kunming Institute of Precious Metals |
Huan Y.,Kunming Sino Platinum Metals Catalyst Co. |
Huan Y.,Kunming University of Science and Technology |
He X.,Kunming Sino Platinum Metals Catalyst Co. |
And 3 more authors.
Xiyou Jinshu Cailiao Yu Gongcheng/Rare Metal Materials and Engineering | Year: 2011
Pore structural parameters of 2 kinds of alumina before and after modification were reported, and with the modified alumina as coating Pd-based catalysts were prepared. The results show that the modified Al2O3-02 has specific area of 134.691 m2 · g-1 and pore structure of 0.5851 cm3 · g-1 and 8.6877 nm. The obtained Pd-based catalyst TWC-02 has superior properties. After calcining the catalyst at 950°C, Pd grains homogeneously disperse in the surface of modified Al2O3-02; even ≥ 1050°C, the dispersity of Pd is still good. Alumina has the effect of structure promoter on Pd-based catalyst. The superiority of the structure character of Al2O3-02 is also proved by a light-off active test.
Hu D.,Kunming Sino Platinum Metals Catalyst Co. |
Hu D.,Kunming Institute of Precious Metals |
Yu J.,Kunming Sino Platinum Metals Catalyst Co. |
Yu J.,Kunming Institute of Precious Metals |
And 3 more authors.
Xiyou Jinshu/Chinese Journal of Rare Metals | Year: 2016
Recycling platinum group metals (PGMs) from spent automobile catalysts which have become the most important PGMs secondary resources is becoming quite important, due to the limitation of natural resource deposits of PGMs and the rapid industrial development. Among the processes of PGMs' recycling from spent automobile catalysts, the hydrometallurgical leaching drew extensive concerns, but the recovery of Rh was the most inefficient. Based on the effects of liquid-solid rate, sodium chlorate, reaction temperature, [H+] concentration, [Cl-] concentration on leaching of rhodium, the leaching kinetics of rhodium extracted from spent automotive catalyst in HCl-H2SO4-NaClO3 medium was studied. The results showed that the leaching process followed the shrinking core model, which indicated that the control factor of the leaching process was the surface reaction. Enhancing the leaching temperature, initial [H+] and initial [Cl-] would accelerate the speed of rhodium leaching and raise the leaching rate. The ratio of liquid to solid and the dosage of oxidant NaClO3 had few influences on the leaching rate of rhodium. The apparent activation energy was determined as 66.719 kJ·mol-1 within the selected temperature range by Arrhenius equation. The apparent reaction progressions of [H+] and [Cl-] were 0.779 and 0.296, respectively. What was more, the correlation coefficients fitting experimental data were more than 0.97.The kinetics study of leaching rhodium from spent automotive catalyst provided some references for the recycle of platinum group metals in industry practice. © Editorial Office of Chinese Journal of Rare Metals. All right reserved.
He X.,Tianjin University |
He J.,Tianjin University |
He J.,Kunming Sino Platinum Metals Catalyst Co. |
Meng M.,Tianjin University
Catalysis Letters | Year: 2011
A series of Ce1-x Zr x O2 (x = 0, 0.1, 0.2, 0.3) solid solution supported lean-burn NO x trap (LNT) catalysts K/LaCoO3/Ce1-x Zr x O2 were prepared by successive impregnation. After sulfation the supported perovsikte LaCoO3 was well maintained; reducing treatment partly destroyed the perovsikte, but it can be well recovered by re-oxidation treatment. Based on NO x storage and sulfur-resisting performance of the catalysts, the optimal atomic ratio of Zr in Ce1-x Zr x O2 support is x = 0.2. The catalyst K/LaCoO 3/Ce0.8Zr0.2O2 exhibits much better NO x storage capacity than the Pt-based catalyst Pt/K/Ce 0.8Zr0.2O2, which is highly related to its stronger capability for NO to NO2 oxidation. During NO x storage much larger amounts of nitrate and nitrite species were identified by in situ DRIFTS over perovskite-based catalysts than over Pt-based one. The H 2-TPR results reveal that after deep sulfation little sulfur species were deposited on the catalyst K/LaCoO3/Ce1-x Zr x O2, showing strong sulfur-resisting ability. As a result, it is thought that the full replacement of Pt by perovskite LaCoO 3 in the corresponding LNT catalysts is feasible. © 2011 Springer Science+Business Media, LLC.
HE X.,Kunming University |
HE X.,Kunming Sino Platinum Metals Catalyst Co. |
SUN J.,Kunming University |
HUAN Y.,Kunming University |
And 4 more authors.
Journal of Rare Earths | Year: 2010
Al2O3 and Ce-Zr mixed oxides are important components of the automobile three-way catalyst. Various contents modifying A12O3(GAL) was physically introduced into Ce-Zr-Al mixed oxides (CZA) to form series of GAL/CZA composition. The Pd/Rh catalyst samples were prepared by different GAL/CZA support loading Pd/Rh, then aged at 950 °C for 6 h. The catalytic behavior of different Pd/Rh catalyst samples was studied. Surface area, oxygen storage capacity (OSC) and H2 adsorption capacity (TPR) of fresh and aged samples were examined by means of BET and H2-TPR. The analysis results of surface area and chemical absorption reduction showed that GAL content in GAL/CZA composition was the main effect on surface area stability of Pd/Rh catalyst. Compared with pure CZA, CZA by mixing physically with GAL could promote the surface area and stability of Pd/Rh catalyst. On the other hand, higher OSC and OSC stability should depend on CZA content in GAL/CZA composition. Compared with pure GAL, higher CZA content in GAL/CZA can promote the OSC and OSC stability of Pd/Rh catalyst. TPR showed that the optimal range of composition (CZA>60%) could obtain high reduction activity. GAL and CZA had a synergistic effect on the surface area and OSC of catalyst. The suitable mixing ratio of GAL and CZA in GAL/CZA could simultaneously get more surface area and OSC to make better catalytic activity of Pd/Rh catalyst. © 2010 The Chinese Society of Rare Earths.