Facet-engineered Pt/CeO2 oxygen carriers for efficient low-temperature chemical looping steam methane reforming

In this study, 1 wt% Pt-loaded cubic CeO 2 (c-CeO 2 ) oxygen carriers were developed for low-temperature chemical looping steam methane reforming (CL-SMR) to investigate hydrogen and syngas production. c-CeO 2 nanostructures were synthesized via a supercritical hydrothermal method and functionalized with Pt through impregnation. Well-dispersed Pt nanoparticles on the {001} facets enhanced oxygen mobility and redox kinetics, as confirmed by HR-STEM, XRD, XPS, and H 2 /CH 4 -TPR analyses. Kinetic experiments in a differential fixed-bed reactor demonstrated stable methane conversion and continuous H 2 /CO production at 500 °C, with nearly pure hydrogen generated during the steam oxidation step. The introduction of 1 wt% Pt increased the oxygen release capacity by 15.7-fold (1.214 mmol-O·g −1 ) and the mass-specific release rate by 37.1-fold (0.157 mmol·g −1 ·min −1 ) compared to bare c-CeO 2 . These findings indicate that 1 wt% Pt loading combined with facet engineering enables efficient low-temperature CL-SMR, providing mechanistic insights and potential relevance for industrial-scale hydrogen and syngas production.