scholarly journals A new class of Cu/ZnO catalysts derived from zincian georgeite precursors prepared by co-precipitation

2017 ◽  
Vol 8 (3) ◽  
pp. 2436-2447 ◽  
Author(s):  
Paul J. Smith ◽  
Simon A. Kondrat ◽  
Philip A. Chater ◽  
Benjamin R. Yeo ◽  
Greg M. Shaw ◽  
...  
Keyword(s):  
Ammonium Carbonate ◽  
New Class ◽  
Copper Zinc ◽  
Co Precipitation

Zincian georgeite, an amorphous copper–zinc hydroxycarbonate, has been prepared by co-precipitation using acetate salts and ammonium carbonate.

Reaction Process of Al2(1-x)MgxTi1+xO5 Composite Powder by Chemical Co-Precipitation and Subsequent Sintering

2007 ◽  
Vol 336-338 ◽  
pp. 2347-2349 ◽  
Author(s):  
Shang Yue Shen ◽  
Rui Yang ◽  
Qiang Shen ◽  
Chuan Bin Wang ◽  
Lian Meng Zhang
Keyword(s):  
Heat Treatment ◽  
Composite Powder ◽  
Ammonium Carbonate ◽  
Raw Materials ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Reaction Process ◽  
Dynamics Analysis ◽  
Thermal Dynamics ◽  
Co Precipitation

Al2(1-x)MgxTi1+xO5(x=0.05-0.3) composite powder was prepared by the method of chemical coprecipitation and subsequent sintering using TiCl4, MgCl2 and AlCl3 solution as the raw materials, and ammonia and ammonium carbonate as the solvent. Thermal dynamics and kinetic dynamics analysis of the precursor during the heat treatment were explored in detail, and the reaction process of Al2(1-x)MgxTi1+xO5 (x=0.3) composite powder was confirmed. Results show that, as the temperature increases MgO reacts with TiO2 of anatase phase to form MgTi2O5. At about 650°C, anatase transfers into rutile. Then MgTi2O5 reacts with Al2O3 to produce MgAl2O4 at 900°C. When the temperature is above 1100°C, the desired Al2(1-x)MgxTi1+xO5(x=0.3) composite powder is synthesized by the reaction of MgAl2O4, Al2O3 and TiO2 of rutile phase.

scholarly journals Synthesis of alumina/YAG 20 vol% composite by co-precipitation

2011 ◽  
Vol 5 (4) ◽  
pp. 187-191 ◽  
Author(s):  
Radosław Lach ◽  
Krzysztof Haberko ◽  
Mirosław Bucko
Keyword(s):  
Elevated Temperatures ◽  
Ammonium Carbonate ◽  
Nitrate Solution ◽  
Yttrium Nitrate ◽  
X Ray Diffraction ◽  
Full Transformation ◽  
X Ray ◽  
Co Precipitation

Co-precipitation of alumina/YAG precursor from aluminum and yttrium nitrate solution with ammonium carbonate results in dawsonite. Its crystallographic parameters differ from the compound precipitated with no yttrium additive. It suggests that yttrium ions become incorporated into the dawsonite structure. The DSC/ TG and X-ray diffraction measurements show decomposition of dawsonite at elevated temperatures resulting in ?-Al2O3 and then ?- and ?-alumina modifications. Full transformation to ?-Al2O3 and YAG occurs at temperatures higher than 1230?C. Starting powder for the sintering experiments was prepared using the coprecipitated precursor calcined at 600?C. Seeding of such powder with 5 wt.% ?-Al2O3 results in material of 98% density at 1500?C. Much lower densification show compacts of unseeded powder.

Oxidation of Copper Zinc Oxide Catalysts by Carbon Monoxide

2011 ◽  
Vol 332-334 ◽  
pp. 564-567
Author(s):  
Lin Tong Wang
Keyword(s):  
Carbon Monoxide ◽  
Zinc Oxide ◽  
Low Temperatures ◽  
Oxide Catalyst ◽  
Specific Activity ◽  
Oxide Catalysts ◽  
Copper Zinc ◽  
Co Precipitation ◽  
Copper Zinc Oxide ◽  
Oxidation Of Carbon Monoxide

Copper zinc oxide catalysts are effective for the ambient temperature carbon monoxide oxidation and display higher specific activity than the current commercial hopcalite catalyst. We investigate the copper zinc oxide catalyst prepared by co-precipitation under different atmospheres for the oxidation of carbon monoxide at low temperatures and these systems are now worthy of further investigation.

The Effect of Precipitants on Co-Precipitation Synthesis of MgO-ZrO2 Powders

2013 ◽  
Vol 788 ◽  
pp. 132-135 ◽  
Author(s):  
Yuan Jun Huang ◽  
Ting Liu ◽  
Min Liu
Keyword(s):  
Grain Size ◽  
Ammonium Carbonate ◽  
Nanosized Powders ◽  
Ammonium Hydrogen Carbonate ◽  
Hydrogen Carbonate ◽  
Ammonium Hydrogen ◽  
Precipitation Synthesis ◽  
Co Precipitation

MgO-ZrO2nanosized powders have been synthesized via the co-precipitation route using ammonia, ammonium carbonate and ammonium hydrogen carbonate as precipitant, respectively. The three different powders were characterized by TG-DSC, XRD and SEM. And the sinterability behavior of each powder also has been investigated. The results indicated that uniformly dispersed and much looser MgO-ZrO2nanosized powders could be obtained when the ammonium carbonate, especially the ammonium hydrogen carbonate were used. When ammonia was used, some agglomeration could be observed. The crystalline grain size of the three powders is closed to each other. Due to the existing of agglomeration, the sintered samples prepared by using ammonia as precipitant exhibited poorer sinterability than that of using carbonates as precipitant.

scholarly journals DETERMINATION OF COPPER, ZINC, CADMIUM AND LEAD IN WATER USING CO-PRECIPITATION METHOD AND RAMAN SPECTROSCOPY

2013 ◽  
Vol 06 (03) ◽  
pp. 1350021 ◽  
Author(s):  
YANDE LIU ◽  
YU SHI ◽  
LIJUN CAI ◽  
YONG HAO ◽  
CHUNJIANG ZHAO
Keyword(s):  
Heavy Metals ◽  
Raman Spectroscopy ◽  
Precipitation Method ◽  
Least Squares Regression ◽  
Precipitation Procedure ◽  
Calibration Methods ◽  
Zinc Cadmium ◽  
Copper Zinc ◽  
Co Precipitation ◽  
Cadmium And Lead

Mn co-precipitation method combined with Raman spectroscopy were used to determine trace heavy metals (copper, zinc, cadmium and lead) in water sample. Different concentrations of heavy metals including copper, zinc, cadmium and lead in water samples were separated and enriched by Mn 2+-phen-SCN- ternary complex co-precipitation procedure. The Raman spectra of co-precipitation sediments were collected using confocal micro-Raman spectrometry. Different preprocessing treatments and regression calibration methods were compared. The best models using partial least squares regression (PLS) of copper, zinc, cadmium and lead were built with a correlation coefficient of prediction (Rp) of 0.979, 0.964, 0.956 and 0.972, respectively, and the root mean square error of prediction (RMSEP) of 6.587, 9.046, 9.998 and 7.751 μg/kg, respectively. The co-precipitation procedure combined with Raman spectroscopy method are feasible to detect the amount of heavy metals in water.

A low-temperature co-precipitation approach to synthesize fluoride phosphors K2MF6:Mn4+(M = Ge, Si) for white LED applications

2015 ◽  
Vol 3 (8) ◽  
pp. 1655-1660 ◽  
Author(s):  
Ling-Ling Wei ◽  
Chun Che Lin ◽  
Mu-Huai Fang ◽  
Mikhail G. Brik ◽  
Shu-Fen Hu ◽  
...  
Keyword(s):  
Low Temperature ◽  
Alkali Metal ◽  
White Light ◽  
Light Emitting Diodes ◽  
White Led ◽  
Light Emitting ◽  
Red Phosphors ◽  
New Class ◽  
Co Precipitation ◽  
White Light Emitting Diodes

A new class of Mn4+activated alkali-metal hexafluoride red phosphors are emerging for white light-emitting diodes because of their sharp red line2Eg→4A2gemissions (600–650 nm) excited by irradiation of4A2g→4T1g(320–380 nm) and4A2g→4T2g(380–500 nm) transitions.

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