Construction of the sandwich-structured Ce_0.8Zr_0.2O₂-Ni@LDO catalyst for enhancing the coke resistance in dry reforming of methane

Dry reforming of methane (DRM) is considered a highly promising route for converting greenhouse gases into syngas. However, the catalyst deactivation caused by carbon deposition is a major challenge. To address this issue, a sandwich-structured Ce_0.8Zr_0.2O₂@Ni-LDO catalyst was developed, which features a core of a layered double oxide (LDO) supporting Ni nanoparticles, encapsulated by a protective Ce_0.8Zr_0.2O₂ solid solution shell. This unique architecture significantly improved the catalytic activity and coking resistance for DRM. The synthesized catalyst maintained high methane and CO₂ conversion (84.7% and 93.2%) during a 120-h stability test at 750 °C and a gas space velocity of 60,000 mL⋅g-1⋅h-1. Structural and In-situ DRIFTS characterizations revealed that the Ce_0.8Zr_0.2O₂ shell enhanced the interaction with Ni, the oxygen mobility, and CO₂ activation capacity, and altered the distribution of surface intermediates. Moreover, the lattice oxygen of the Ce_0.8Zr_0.2O₂ shell played a crucial role in gasifying carbon precursors before coke formation.