Physisorption Essays

The chemisorption energy is typically in the range of EChem ≈ 20 - 150 KJ/mol H2 and thus significantly higher than the respective energy for physisorption which is in the order of 4-6 kJ/mol H2. This hydride formation is exothermic, as entropy of product is lower than metal and hydrogen gas and the reverse reaction is endothermic. Therefore hydrogen desorption requires heat supply. Hydrogen gas or