Regarding the selection of the NH3 sorbent material, the required reaction conditions defined by the NH3 synthesis need to be considered carefully. Sorbents, such as zeolites or activated carbon (AC), applied e.g., in gas purification, typically operate at temperatures below 150 °C . For the sorption of NH3, Aika et al. and Helminen et al. tested the applicability of these materials. The AC samples showed a specific NH3 uptake in the range of 2 to 3 mmol g -1 (NH3 per sorbent), while the zeolites exhibit capacities of up to 5 mmol g -1 in the temperature range between 50 and 100 °C. Due to weakening of the purely physical interactions between gaseous NH3 and the solid sorbents, a strong decrease in capacity down to less than 1 and 2 mmol g -1 was reported for AC and zeolites, respectively, at temperatures of up to 200 °C . Accordingly, the application of these sorbents for in situ NH3 removal requires strongly reduced reaction temperatures as shown by who performed experiments at 200 °C using Zeolite 4A as sorbent . This temperature limit inherently leads to reduced catalyst activity and restricts the investigations of the in situ removal to industrially less relevant conditions. Thus, implementation of NH3 sorbents with high capacity at elevated temperatures is desirable. Cussler, McCormick and co-workers as well as Aika et al. investigated metal chloride salts, such as MgCl2 or MnCl2, as a high temperature NH3 sorbent. The potential of metal chlorides as sorbents can be seen in the up to 10-fold larger capacities in the range of 20 to 40 mmol g -1 under comparable conditions as the above discussed AC or zeolites. Furthermore, experimental investigation of the sorption at temperatures close to the typical temperature of the NH3 synthesis have been carried out, proving the general feasibility of these materials . Yet, the applicability of pure metal chloride salts as sorbent was found to be strongly limited due to the following reasons: