Compared with gas phase reactions, liquid phase catalytic processes are complex due to the effect of the solvent. The solvent controls many aspects of the overall reaction including solubility of reagents, mass transfer of the reactants and products within the liquid and pore structure as well as adsorption geometry of the adsorbates at the active site. A key question for heterogeneous catalysis is whether the confinement of the solvent within the pore is the same as that found in bulk liquid. Neutron diffraction will be used to investigate and compare the structure of binary mixtures of isopropanol-water in the bulk liquid and in the pores of MCM-41 (pore size ~2 nm). The structure of pure components confined in the silica will also be compared with the structure of the bulk liquid measurements previously reported for IPA and water.