Author/Authors :
SARWAR WATTOO, MUHAMMAD HAMID Quaid-i-Azam University - Department of Chemistry, Pakistan , MAZHAR, MUHAMMAD Quaid-i-Azam University - Department of Chemistry, Pakistan , TUFAIL, MUHAMMAD Ashfaq Ahmad Research Laboratories, Pakistan , WATTOO, FEROZA HAMID University of Sindh - Institute of Biochemistry, Pakistan , AHMAD, MAQSOOD Ashfaq Ahmad Research Laboratories, Pakistan , TIRMIZI, SYED AHMED Quaid-i-Azam University - Department of Chemistry, Pakistan , IQBAL, JAYED University of the Punjab - Institute of Chemistry, Pakistan
Abstract :
XRD have been used to study Pd/?-Al2O3 catalysts prepared by solution impregnation method. Effect of metal loading and calcination and reduction temperatures were studied to observe active metal particles growth. On calcination, growth of tetragonal PdO was observed only at 400 and 500 °C. However, for hydrogen reduced catalysts, fine face centred cubic particles growth was observed even for 300 °C treated catalysts. Catalysts with metal loading 2 % cannot be evaluated by their XRD spectra. In hydrogen reduced catalysts, peaks became sharpened when metal loading was increased to reasonable level. Results showed that XRD technique can be extensively used to study reduced metal particles rather to study oxidised one but to definite metal levels that can show Bragg’s angle of diffraction. It has also been observed that growth of both PdO and Pd particles was increased with the elevated temperature.
