Hydrogen capacity measurements were conducted using a Setaram PCTPro system. Samples were loaded into air-tight stainless-steel vessels under an argon atmosphere, connected to the system, and the volume was calibrated using He gas. Samples were desorbed into static vacuum, and hydrogenation was performed under 105 bar hydrogen. Hydrogen was assumed to be the only gaseous product of the reaction. The direct van't Hoff method 3 was used to determine the enthalpy and entropy of hydrogen absorption. The measurement involves pressurizing the sample with hydrogen at 105 bar at a given temperature, then reducing the pressure in small steps until hydrogen starts desorbing from the sample. The final pressure established in the system is recorded and used for calculating enthalpy and entropy changes using the van't Hoff equation: