Embodiments include methods for recovering petroleum products from a formation containing heavy crude oil. In one embodiment, a method includes flowing a catalytic material containing the nanocatalyst into the formation containing the heavy crude oil and exposing the heavy crude oil and the catalytic material to a reducing agent (e.g., H2). The method further includes positioning a steam generator within the formation, generating and releasing steam from the steam generator to heat the heavy crude oil containing the catalytic material, forming lighter oil products within the formation, and extracting the lighter oil products from the formation. In another embodiment, a method includes exposing the heavy crude oil and the catalytic material to an oxidizing agent (e.g., O2). The nanocatalyst may contain cobalt, iron, nickel, molybdenum, chromium, tungsten, titanium, oxides thereof, alloys thereof, or combinations thereof.