Selective deconstruction of lignocellulose, specifically, the recalcitrant lignin fraction, is a potential route to renewable aromatics. Their production from underutilized lignin could improve the economic competitiveness of biorefineries. To achieve this goal, catalysts must be designed with appropriate active site structures and pore architectures. Porous metal oxides (PMOs) based on MgO/Al2O3 doped with Cu have been shown to convert sawdust cleanly to organic liquids in the presence of supercritical methanol. The nature of the copper-support interaction was characterized by X-ray absorption spectroscopy and X-ray diffraction, transmission electron microscopy and temperature-programmed desorption. In combination with complementary reactivity studies, the results show that the catalytically active species for hydrogenolysis are small Cu0 nanoparticles (NPs) generated in situ. CuPMOs hydrogenate phenolic intermediates, facilitated by deprotonation and adsorption on the basic MgO support. Based on these findings, we are currently working to tailor the metal-support interaction to cleanly cleave lignin substrates, while simultaneously preserving the aromatics.