Reuse of CO-Oxidation Spent Catalysts for Dry Reforming of Methane: Techno-Economic Analysis

We report an upcycling route for Pt-based spent CO-oxidation catalysts in stationary plants. By simple Ni impregnation, the spent modules are converted into active dry reforming of methane (DRM) catalysts (oxiCO/Ni). Under DRM at 750 °C, oxiCO/Ni achieves CH4 and CO2 conversions >73 and >94%, respectively, with high structural and thermal stability maintained over 7 h of continuous operation. The superior activity and resistance to deactivation are attributed to the formation of the NiAl2O4 spinel phase, strong metal–support interactions, and synergistic effects from residual Pt and La in the spent catalyst. A techno-economic analysis was conducted for a recycling plant capable of processing 205 tons/y of raw spent oxiCO catalyst modules, yielding 16.2 tons/y of oxiCO/Ni catalyst for DRM. The profitability analysis showed that the investment in such a project is profitable with a maximum tipping credit of 6500 US$/ton, giving a net present value of US$ 6.9 million, an internal rate of return of 43%, and a discounted payback time of 4 years and 1 month. This approach couples waste minimization with catalyst circularity, delivering both environmental and economic benefits.