Basically, there are two types of adsorption called physisorbed where a molecule is adsorbed without undergoing significant change in electronic structure and chemisorbed where the molecules's electronic structure is significantly changed. Energies for chemisorption are typically eight to ten times higher than required for physisorption. Hayward and Trapnell prepared a reactivity table for a series of gases with metals. For a reaction between copper and nitrogen, they gave a number of 2. Among all the metals in the periodic table, copper seems to be the only metal which adsorbs nitrogen.
Zeolites interact strongly with both hard acids and bases.
Electronegativity and the hardness of the surface of a zeolite are important properties. Zeolites can be doped with acids to change the average electronegativity. According to the density functional theory based on quantum mechanical methods and Taylor series expansion for n a , the following equation can be used essentially to yield an exact result for adsoprtion. Newton-Raphson techniques have been used. The paper examines different test velocities as well as the se of ethylene and benzene as reductants.