La₂Ce₂O₇ Carrier Catalyst for Prominent Steam Reforming Conversion from Medical Waste Pyrolysis Gas to Hydrogen

An efficient catalyst was studied for the steam reforming reaction of the simulated pyrolysis gas from medical waste (MW) in this paper. The impact of Rh supported on different carrier catalysts on the MW pyrolysis steam reforming performance was investigated. In order to acquire the optimum conditions for hydrogen generation, the impact of reaction temperature, steam/medical waste pyrolysis gas ratio, and gas hourly space velocity on hydrogen production efficiency was studied in the steam reforming reaction. Notably, the reforming and stability performance of 1 wt%Rh/La2Ce2O7 surpassed those of 1 wt%Rh/Al2O3. The former achieved an approximately 60% H2 content and sustained stable hydrogen increment (IH2) and hydrogen selectivity (SH2) values around 520% and 99.5–99.7%, respectively. Moreover, the conversions for C1–C5 (Xi) all exceeded 98%. 1 wt%Rh/La2Ce2O7 has such prominent catalytic performance because H2-TPR and XPS results show that RhOx species were more reducible, and more Rh active species are formed due to strong interaction between Rh and the La2Ce2O7 carrier, which are helpful to the hydrocarbon species adsorption to form intermediate CH* species on Rh metal sites. Besides, the high concentration of oxygen vacancies and active oxygen species on the 1 wt%Rh/La2Ce2O7 catalyst enhanced the adsorption and activation of H2O to form intermediate O*, which facilitates the timely oxidation of intermediate CH* species on the Rh metal surface, ultimately alleviating catalyst surface carbon deposition.