Modification of Baturaja natural bentonite (Ca-bentonite) was carried out by cation exchange method into Na-bentonite and H2-bentonite. The formation of Na-bentonite is done by adding saturated NaCl to Ca-bentonite which aims to activate Na+ and replace Ca2+ ions. The formation of H2-bentonite was carried out by adding a saturated solution of NH4Cl in Na-bentonite. Characterization using FTIR s…