Self-assembly synthesis of hierarchical Pd@Ce_xZr_1−xO₂ methane combustion catalysts was obtained.

Atomic Layer Deposition (ALD) was used to prepare Pd@Ce_xZr_1−xO₂-based model catalysts suitable for morphological and chemical state studies.

Below 450 °C, SO₂ irreversibly poisons PdO, causing a partial reduction to Pd and the formation of sulfates in close proximity to the active phase.

At higher temperatures, PdO is more resistant to sulfur poisoning, thanks to the spillover of sulfates from the active phase and/or the direct reaction of SO₂ with the promoter.

Pd@ZrO₂ catalysts showed the best sulfur resistance.