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The development of coke-resistant catalysts for dry reforming of methane (DRM) is critical for sustainable syngas production. To suppress coking, this study investigates the use of Ti3C2Tx and Nb2CTx MXenes as support for Ni catalysts in DRM and benchmarked their performance with conventional catalysts (Ni/γ-Al2O3, Ni/MgAl2O4, and Ni/SiO2). The MXenes were etched using NH4HF2, and a 10 wt% Ni loading on the supports was achieved via wet impregnation synthesis. Ni/Nb2CTx showed the highest H2 consumption (10.4 mmolH2/gcat). DRM was conducted at 700 °C using a feed ratio of CH4/CO2 of 1:1 and a high space velocity (90,000 ml/gcat h). Unlike the other catalysts, Ni/Nb2CTx pre-reduced at 500 °C exhibited a low normalized coking rate (4.41 µgcoke/mmolCH4), a high overall reaction rate (104 ± 13 mmol/gNi.min), and the highest turnover frequency at 16.7 s−1. The apparent CO2 reaction rate at these conditions was similar to the CH4 rate, suggesting that the low coking rate was due to the efficient utilization of dissociated oxygen. Molecular dynamics (MD) simulations performed on NbC(111) and TiC(111) surfaces at 700 °C and atmospheric pressure reveal that the efficient utilization was mediated by rapid oxygen spillover. The average oxygen velocity from the simulations was slightly higher on NbC (0.0969 Å/fs) than on TiC (0.0961 Å/fs). Both MXene supports are transformed to stable oxycarbides during DRM, and Nb2CTx was stable for 50 h TOS. This investigation not only highlights the potential of Ni/Nb2CTx as a coke- and sintering-resistant catalyst but also demonstrates the role of MXenes supports in the DRM process.