Dual-layered paper-structured catalysts for sequential desulfurization and methane-steam reforming of simulated biogas containing hydrogen sulfide

Biogas-powered fuel cells that use low-quality biogas produced from organic waste hold a great promise for providing ultra-clean electric energy with on-site power generators. However, natural biogas contains a small amount of H₂S, which causes a rapid deactivation of steam-reforming metal catalysts, such as Ni. In this work, we successfully prepared two types of paper-structured catalyst, separately containing manganese oxides (MnO_x) and nickel/magnesium oxides (Ni/MgO), for desulfurization and methane-steam reforming, respectively. In the sequential desulfurization and methane-steam reforming, paper catalyst assembly, designed by stacking MnO_x papers upstream and Ni/MgO papers downstream in a dual-layered form, enabled continuous hydrogen production from simulated biogas containing ca. 2000 ppm H₂S impurities, whereas single-layered Ni/MgO papers immediately lost their catalytic activity due to the H₂S poisoning. This combination of flexible, stackable, and easy-to-handle paper-structured catalysts has the potential to improve the energy efficiency and to process economics of providing hydrogen to biogas-powered fuel-cell systems.