Coke-resistant via promoting CO2 dissociation over ultrathin Sm-doped MgAlOx-encapsulated Ni nanoparticles in DRM

The severe carbon deposition that plagues conventional Ni catalysts in dry reforming of methane (DRM) originates from the kinetic mismatch between CH 4 cracking and CO 2 dissociation. Here, we design an atomically thin Sm-doped MgAlO x overlayer to encapsulate Ni nanoparticles, creating a confined reaction environment that intrinsically couples these two critical steps. The Sm-induced electron donation to Ni accelerates CH 4 dissociation by weakening the C-H bonds, while the Sm-doped thin overlayer with rich oxygen vacancies facilitates the rapid decomposition of CO 2 -derived carbonate intermediates (m-CO 3 2− ) and shortens the diffusion path for the resultant active oxygen species to gasify surface cavrbon precursors. The optimized catalyst achieves high conversions of CH 4 (91.0%) and CO 2 (94.0%) at 800 °C, reducing carbon deposition from 39.47% to 9.50%, and maintains stable performance over 100  h. This work demonstrates that precise reducible-oxide overlayers engineering can intrinsically align reaction kinetics to break the classical deactivation cycle of Ni-based catalysts in DRM.