On the measurement of copper surface area by oxygen chemisorption Original Research Article

Due to the multiplicity of problems recently evidenced by the widely used N2O decomposition technique, the oxygen chemisorption technique for the measurement of Cu surface area was updated and optimized. A standard procedure was defined, which allows to obtain reliable and reproducible data. In particular, no arbitrary assumption was made for the Cu/O chemisorption stoichiometry and for the degree of surface coverage. Conversely an experimental value of the average Cu/O surface ratio, including the degree of coverage, was determined by XRD–WAXS data. The value obtained (2.35) corresponds to a chemisorption stoichiometry Cu/O=2 and to about 15% unoccupied surface Cu atoms. The proposed technique has been successfully used for the characterization of several commercial low-temperature water gas shift catalysts (Cu-ZnO-Al2O3).