We describe a new experiment that combines transmission based structural probes, such as dispersive EXAFS (EDE), with diffuse reflectance infrared spectroscopy (DRIFTS) and mass spectrometry (NIS), at high time resolution. The potential and limitations of this experiment are discussed, and an example of its application to the study of fundamental steps occurring during gas-solid interactions is given; that of oxidation and reduction of alumina supported Rh at 573 K using NO and H-2, and the structural-reactive role of linear (Rh(NO+)) Rh-nitrosyl species within these processes. (c) 2006 Published by Elsevier B.V.