Synthesis of Co-rich CoAPO-5 molecular sieves: a comparison between glycerol and water as solvent.
CoAPO-5 molecular sieves have been synthesized with glycerol and water as solvent in order to maximize the degree of isomorphous substitution of Co2+ ions in the AFI framework. These CoAPO-5 molecular sieves have been characterized with X-ray diffraction, inductively coupled plasma-atomic emission spectroscopy, scanning electron microscopy, electron microprobe microanalysis, N2 sorption, and UV-visible-NIR-diffuse reflectance spectroscopy techniques. Optimum conditions for the synthesis of Co-rich single-phase and highly crystalline CoAPO-5 molecular sieves were obtained by varying the [Co]:[Al] ratio in the synthesis gel and the synthesis time. It will be shown that highly crystalline hexagonal single-phase CoAPO-5 crystals with a size between 3 and 10 microns and a substitution degree of about 13% can be obtained from a 0.7CoO.0.65Al2O3.1P2O5.1(C2H5)3N.40HOCH2CHOHCH2OH gel at 190 degrees C after 14 days of synthesis. This substitution degree is substantially higher than that for CoAPO-5 materials synthesized in the presence of water (i.e., about 7.5%).
D017607:Aluminum Compounds / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D005990:Glycerol; D008855:Microscopy, Electron, Scanning; D036103:Nanotechnology / Q000379:methods*; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D010710:Phosphates / Q000737:chemistry*; D012997:Solvents; D014867:Water; D014961:X-Ray Diffraction
D017607:Aluminum Compounds; D010710:Phosphates; D012997:Solvents; D014867:Water; D003035:Cobalt; C012714:aluminum phosphate; D005990:Glycerol