Nickel is considered an economically feasible catalyst for the dry reforming of methane (DRM) owing to its high activity. Because the highly endothermic DRM requires a high reaction temperature to activate both CH₄ and CO₂, deactivation of the Ni catalyst may be induced by sintering and carbon coking. To mitigate catalyst deactivation, Ni/CeO₂ catalysts composed of monodisperse Ni nanoparticles supported on CeO₂ nanorods are designed and coated with Al₂O₃ layers by atomic layer deposition (ALD). The performance of the catalyst in DRM and amount of carbon deposited are correlated with the thickness of the Al₂O₃ layer in the Ni/CeO₂/Al₂O₃ catalysts. As the number of ALD cycles increases from 1 to 10, the conversion of CO₂ and CH₄ at 700 and 800 °C decreases, but the Ni/CeO₂/Al₂O₃ catalysts remain coke-free as thermogravimetric analysis shows no weight loss up to 800 °C. The Al₂O₃ layer generated by ALD curtails the coking substantially, but the weakly metallic character of Ni and blocking of Ni sites by the Al₂O₃ layer are the major factors contributing to decreasing the catalytic conversion. The ALD technique provides an efficient way to fabricate atomically controlled oxide layers for improving the stability of catalysts against coke deposition and sintering.