detection of temperature changes in the vicinity of a respective formulation due to reaction endotherm or exotherm the contacting step can be carried out in the presence of compounds which modify the distribution of the metal within the porous support the candidate catalyst formulations can be contacted in the form of spots or layers on the surface of a support containing a washcoat supported by an underlayer the stabilizing step can be carried out with a temperature gradient or other means whereby certain candidate catalyst formulations are exposed to different temperatures the stabilizing can comprise calcining steaming drying reaction ion exchange and or precipitation the detection of temperature changes due to reaction can employ a correction for emissivity variations associated with differences in chemical composition the array of formulations to be tested can comprise preformed metallocenes or other catalytic complexes fixed to a support the infrared radiation can be detected through the use of nondispersive infrared spectroscopy or infraredsensitive photographic film the detector means can comprise means for physically scanning over an array of candidate formulations observations at multiple wavelengths can be processed by mathematical manipulation e g transformation weighted summation and or subtraction etc reaction activity reactants or products can be detected through the use of an added reaction which signals the presence of reaction or particular compounds or classes of compounds.