Understanding the structure of liquid reagents and solvents in the catalyst pores is critical to design selective and efficient processes. For example, in the hydrogenation of aldehydes and ketones, we have shown the selectivity and reaction rates are controlled by liquid structure of water/2-propanol solvent mixtures. In continuation of a previous beamtime allocation (RB910286), this proposal is intended to develop an experimental protocol to determine the liquid structure in MCM41 pores by using recently developed capillary condensation technique from the gas phase to enable controlled filling of the MCM41 pores. We intend to establish the proof of principle that the structure of liquid mixtures near the catalyst surface can be successfully determined using total neutron scattering. There is significant potential to extend this protocol to industrially important catalytic processes.