The Temkin isotherm, like Freundlich is one of the earliest reported isotherm and assumes the heat of adsorption decreases linearly with increasing coverage.
The Tempkin isotherm has a convenient linear form and is readily solve for β and A.
The Temkin isotherm is part of the standard Micromeritics physical adsorption isotherm modelling package and has also been added to MicroActive.
Temkin, M.I., and V. Pyzhev, Acta Physiochim. URSS 12,217(1940)