Corrosion of additively manufactured (i.e., 3D printed) aluminum packing devices, developed to enhance heat and mass transfer in CO2 absorption columns using amine-CO2 scrubbing solutions, is investigated in this paper. The aluminum structures printed by selective laser melting with Al-10Si-0.3Mg feed powder are susceptible to corrosion in aqueous monoethanolamine, both fresh and used CO2-saturated solutions. The efficacy of corrosion-protective surface layers of aqueous polyether–ketone–ketone (PEKK) dip coating to provide amine corrosion resistance to the 3D printed aluminum structure is also evaluated. PEKK nanothick layers were coated on the corrugated surface of a 3D printed structure, identical to that of the intensified device, yielding 27 times higher corrosion resistance than the uncoated Al alloy surface. A systematic long-term electrochemical corrosion analysis revealed that a multilayer PEKK dip coating protocol enables protection of the 3D printed Al alloy surface in various CO2–monoethanolamine solutions.