| 초록 |
Nickel is considered an economically feasible catalyst for the dry reforming of methane (DRM). Because the highly endothermic DRM requires a high reaction temperature, deactivation of the Ni catalyst may be induced by sintering and carbon coking. To mitigate 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 decreases, but the Ni/CeO2/Al2O3 catalysts remain coke-free characteristics. The Al2O3 layer 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. |
