The surface chemistry of SZO is distinctly complex, yet this material is prepared from very simple precursors and derivatives are used industrially in alkane isomerization reactions. This is potentially attractive in the context of polymer upcycling reactions that generally feature noble metal nanoparticles or air/moisture sensitive organometallics as active catalysts for these reactions. Clear limitations persist, however. Not addressed in this contribution is the deactivation of the pyrosulfate site, which likely proceeds by reduction of SO3 to SO2 and water. Increasing productivity of SZO in polymer degradation is required. Two plausible strategies are oxidation of SO2 back to SO3, which will likely also introduce competitive polymer oxidation reactions that could outcompete catalysis, or modifications of the oxide to prevent or restrict reduction of SO3 to SO2.