New composite sorbents "chlorides of alkaline-earth metals confined to porous alumina" were synthesized and tested for ammonia abatement in a fixed-bed flow adsorber at 25-300 degrees C. It was found that the matrix modification with the salts leads to an increase in its dynamic sorption capacity in the row BaCl2 < CaCl2 < MgCl2- This can be caused by a salt-ammonia interaction that results in the formation of ammonia complexes. The dynamic capacity was found to strongly decrease with temperature. The maximal sorption capacity was detected for a sorbent based on MgCl2, It equals 58.6 and 11.6 mg/g at T = 25 and 300 degrees C, respectively, or 3.2 and 0.6 mole of ammonia per 1 mole of the salt. The data obtained can be used for the analysis of the dynamic behavior of the new sorbents in flow systems for the ammonia removal from gas mixtures, which can be of.high interest for gas separation, chemical engineering and catalysis.