Abstract: Methods and compositions for catalytic heavy oil recovery are disclosed herein. The disclosed methods utilize novel colloidal catalysts, which may catalyze hydrogenation reactions in heavy oil deposits. These colloidal catalysts are dispersible in liquid dispersants, which are also injected into the reservoir. Embodiments of the disclosed method enable the distribution of catalytic particles throughout portions or all of the reservoir. The H2 injected is also transported throughout the reservoir by diffusion and or bulk flow. On coming in contact with the catalyst, hydrogen and components of the crude oil react to produce a lighter, more hydrogenated crude. This results in a reduction in viscosity of the crude oil, which in turn may enable higher reservoir recoveries.