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Ammonia with toxic and corrosive features needs advanced protective materials and removal tools, although it is a vital component in human food supply processes. So, to satisfy these requirements, materials with high adsorption capacity and affinity for ammonia should be developed. The present research has been focused on a series zinc-based metal–organic frameworks (MOF) containing mixed ligands, biphenyl dicarboxylic acid (BPDA) and tris­(4-(4H-1,2,4-triazol-4-yl)­phenyl)­amine (TTPA), which are modulated by different anions including CH3COO–, CF3COO–, and CF3SO3 –. Ammonia uptake capacity was measured via static and dynamic conditions under 50% relative humidity. Among all compounds, CF3SO3 – anion could enhance the ammonia uptake capacity of MOFs up to 177.85 and 349 mg/g during static and breakthrough measurements, respectively, so that 83.30% of the total uptake capacity (at P/P o = 1.0 and 298 K) was achieved at low relative pressure range (up to 0.1). The isosteric heats of ammonia adsorption on PFC-27 and derivatives were calculated in the range of 7.03–10.16 kJ mol–1 so that they increased upon CF3SO3 –, CF3COO–, and CH3COO– ion incorporation. This is potentially beneficial for enhanced ammonia adsorption. Interestingly, adsorption capacities were retained with only slight changes after five cycles and three regeneration temperatures, 25 °C, 60 °C, and 120 °C, under vacuum. The special affinity for NH3 adsorption and MOF phase stability after desorption is clearly proved by FTIR spectra and PXRD analysis, respectively. Generally, the results suggest that ion insertion modification is an efficient strategy for enhancement of MOF adsorption performance.

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