Binary salt mixture barium bromide-barium chloride for sorption applications

• Temperature ramp, jump and TGA methods were used to characterise sorption reactions between BaCl 2 -Br 2 mixtures and NH 3 . • Samples with different BaCl 2 and BaBr 2 molar ratios (1:3, 1:1, and 3:1) were prepared and analysed. • Results confirmed the presence of new compounds with sorption properties that vary according to the salt molar ratios. • Anion salt mixture “bands” expand the temperature range of single salts for use in sorption cycles and thermal storage. Large temperature ‘jump’ and ‘ramp’ techniques, along with thermogravimetric analysis (TGA), were employed to characterise the sorption reactions of halide salt mixtures with ammonia. Using LTJ and FTR methods, a 1:1 mixture containing 50 % BaCl 2 and 50 % BaBr 2 by molar weight was studied but remained inconclusively characterised. To investigate further, samples with different BaCl 2 and BaBr 2 molar ratios (1:3, 1:1, and 3:1) were prepared. TGA results confirmed the presence of a new compound with sorption properties that vary in proportion to the molar ratios of the component salts. The effect of altering these molar ratios was evident: BaCl 2 -rich mixtures resembled pure BaCl 2 salt behaviour, while BaBr 2 -rich mixtures behaved more like pure BaBr 2 salt. Adsorption and desorption findings indicated an optimal bromide content at 50 %, beyond which the position of the reaction band becomes relatively stable—a pattern not observed in BaCl 2 -heavy mixtures. These distinct reaction “bands” expand the temperature operating range of sorption technologies by up to 30 °C, suggesting that tailored anion halide salt mixtures could be developed for advanced heat pumping and thermal storage applications.