Page - 146 - in Advanced Chemical Kinetics

3.Structural characterization 3.1.XRDanalysis XRDpatterns of Sep, FA, FA-Sep and the supported catalysts are shown at both low-angle (2θ<10 )andhigh-angle (20 <2θ<60 ) ranges(Figure1A).Thecharacteristicd110reflection of the Sep appears at 7.24 (2θ )with a basal spacing of 12.19Å. The pattern of FA includes amorphousaluminosilicate glass (asmajor) phase.Quartz (SiO2) reflectionsofd100,d101 andd110aredetectedat 20.8, 26.6 and36.6 (2θ), respectively.Minor constituents of calcite (CaCO3) reflectionsofd101andd104areobservedat 30 and48 (2θ), respectively. Lime (CaO)reflectionat62 (2θ )ofd104 isalsonoticed.For theFA-Sepsupport, the intensitiesofd 1 1 0 reflection andall other high angle peaksdecrease. Supported catalysts reveal d 1 0 0, d 002,d101,d102,d110,d103andd200crystalplanesofZnOat31.9, 34.6, 36.4, 47.7, 56.7, 63.1 and 66.6 (2θ), respectively (JCPDS file no. 36-1451). The peak position and basal spacing of the d 1 1 0 reflection do not change significantly for the FA-Sep and supported catalystsduetothenon-expandablenatureof theSep.TheZnOsignalsare intensifiedwiththe increasing loadingconcentrationswhile the retainedFA-Seppeaksdecrease significantly. Scherrer’sequation isusedtoevaluateZnOcrystallinesizes (DZnO) in thesupportedcatalysts. According to the d 1 0 1 reflection of ZnO, DZnO values are found as 16.1, 13.1, 9.85 and 11.7 nm for 0.25MZnO, 0.125MZnO-FA-Sep, 0.25MZnO-FA-Sep and 0.5MZnO-FA-Sep, respectively (Table1).Hence, formationofZnOaggregates is inhibited in thepresenceof the FA-Sep support. The reduction in theZnOcrystalline sizes in the formof supported catalysts and the decrements in the FA-Sep reflectionsmay suggest distribution of ZnOnanoparticles over thesurfaceandbulk. Figure1A. XRDpatternsofSep,FA-Sepandsupportedcatalysts (Z:ZnO). Advanced Chemical Kinetics146