The preparation of metal oxide CaO based on eggshell has been carried out by decomposition of various temperature at 600, 700, 800, 900 dan 1000°C. Catalyst were characterized using XRD difiractometer. Furthemore, from the XRD pattem can be the determined the optimum temperature for preparation of CaO, then the characterization of CaO will be extended using FT-IR spectrophotometer and BET anal…