Precipitation techniques, synthesis

The entire spectrum of tools in synthetic inorganic chemistry, including high temperature methods, precipitation, solvothermal synthesis, sol-gel chemistry, chemical vapor deposition (CVD), and soft matter techniques adopted in part from organo-metallic chemistry, have been applied to synthesize the active mass of catalysts. Table 4.2.1 summarizes basic techniques. The preparation methods differ whether... 

Recently it was shown that Raney copper has some activity for methanol synthesis [7,8], However, ZnO deposition on the surface is essential to a highly active copper surfaces [7], Previous investigations sought to improve the ZnO content in the leached Cu structures by changing the Zn content of the Al-Cu-Zn alloy [2-4], This paper describes a leaching/precipitation technique which produces ZnO promoted Raney Cu (RCD) and ZnO enriched Raney Cu-Zn (RCZD)... 

The applicability of the Pt deposition precipitation technique (DP) on mesoporous silica has been evaluated and discussed. A detailed synthesis procedure is given, and a suitable support from the SBA-15 family has been identified. The material synthesized at the conditions described here was clearly able to withstand the severe conditions of the DP treatment, indicating improved hydrothermal stability. The incorporation of the active species was accomplished without compromising the structural integrity of the parent material, as monitored by XRD and N2-sorption measurements. Using UV-Vis diffuse reflectance spectroscopy we were able to detect the platinum surface complex that coexists with platinum nanoparticles on the impregnated solid. 

Tor powder synthesis a large variety of methods is available, for example mixed-oxide solution precipitation or emulsion precipitation. Figure 8.11 shows as an example a (Y,Gd)202 powder prepared by three different precipitation techniques. The powders obtained ate different in particle morphology as well as in particle size. Powders prepared by the citrate and the oxalate precipitation techniques are strongly agglomerated [14], From powders derived in this way, compacts are formed. These powder compacts demonstrate total luminescent properties, but have still low light output due to the high porosity of about 50 vol.%. 

Zhi et al. [41] investigated the effect of synthesis method on the WGS activity of Cu-Ce-La catalysts. They prepared the catalysts using co-precipitation, homogeneous precipitation and deposition-precipitation techniques. Among the various catalysts, the catalysts synthesized by co-precipitation method exhibit better activity. Then, they investigated the effect of precipitator. The sequence of activities are NaOH (61.10%)>NaOH-h(NH2)2CO (60.98%)> (NH2)2C0 (57.4%) NH3 X H2O (5.35%) at 300 °C. 

Kierzkowska AM, Poufikakos LV, Broda M, MUller CR (2013) Synthesis of calcium-based, Al203-stabilized sorbents for CO2 capture using a co-precipitation technique. Int J Greenhouse Gas Control 15 48-54... 

Several synthesis methods have been developed for preparation of perovskite powders, sueh as solid-state reaction, combustion method and some solution chemistry methods, for example, sol-gel process, co-precipitation technique, and citrate process [14-17]. In this ehapter we will describe three methods of LSM synthesis more detailed solid-state, eombustion and citrate methods. 

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