Development and catalytic performance of metal-impregnated porous clay heterostructures for efficient steam methane reforming

Hydrogen is regarded as a clean and sustainable energy carrier, with steam methane reforming (SMR) being the most widely applied process for large-scale hydrogen production. However, the efficiency of SMR is largely dependent on catalyst performance, stability, and activity of the active metal species. In this study, montmorillonite (MMT) was modified into porous clay heterostructures (PCH) to create a high surface area, thermally stable support for Ni, Cu, and Ni–Cu bimetallic catalysts prepared by the impregnation method. Structural analyses using FTIR, XRD, SEM–EDX, XPS, and BET confirmed the successful transformation of MMT into PCH with significantly enhanced porosity, as well as the effective incorporation of Ni and Cu oxides within the clay framework. While Ni-impregnated PCH (10Ni_PCH) achieved the highest methane conversion (85.6%) and hydrogen yield (72.4%), it also exhibited higher carbon formation (1.98 mmol g cat −1 ). In contrast, Cu-impregnated PCH (10Cu_PCH) showed limited activity, whereas the bimetallic Ni–Cu catalyst (5Ni5Cu_PCH) demonstrated a comparable hydrogen yield (72.1%) with reduced carbon formation relative to Ni alone. These findings highlight the potential of metal-impregnated porous clay heterostructures as promising catalyst systems for hydrogen production via steam methane reforming, with bimetallic Ni–Cu compositions offering a balance between high activity and improved coke resistance.