Environmental needs associated with green chemistry require a reduction in the use of reaction solvents and separation materials. Heterogenization of homogeneous catalysts can be used to simplify the recovery steps in a reaction process. The use of a supercritical fluid for reaction and separation can further reduce the need for organic solvents throughout the process. The current paper describes the development of a tethered homogeneous catalyst for the hydro-formylation of 1-hexene in supercritical carbon dioxide that is shown to be active, stable, and selective for the reaction. A reaction rate model that shows similarities to both the homogeneous and heterogeneous models is developed based on the assumption of a tethered catalyst and provides rate constants that are consistent with previous estimates.