Sulfur deactivation and regeneration behavior of the Pd/Al₂O₃ catalyst has been investigated via experimental characterization and density functional theory (DFT) simulations. During the sulfur exposure, PdO crystallites grow slightly while bulk Al₂(SO₄)₃ forms on the support. DFT calculations indicate that SO_x species interact strongly with the catalyst surface making it chemically inactive in agreement with the experimental results. During the regeneration treatment (CH₄ conditions), PdO particles reduce, Al₂(SO₄)₃ is partially removed, and the activity for CH₄ conversion is increased. No full recovery can be observed due to remaining Al₂(SO₄)₃, the formation of encapsulating sulfur species, and the partial reduction of PdO particles. To reoxidize Pd, the catalyst is further regenerated (O₂ conditions). The resulting CH₄ conversion is at the same level than with the regenerated catalyst. Thus, a small amount of Al₂(SO₄)₃ appears to have a stronger effect on the performance than the state of Pd.

通过实验表征和密度泛函理论（DFT）模拟研究了Pd / Al ₂ O ₃催化剂的硫失活和再生行为。在硫暴露期间，PdO微晶生长缓慢，而在载体上形成块状Al ₂（SO ₄）₃。DFT计算表明，SO _x种类与催化剂表面强烈相互作用，使其化学惰性，与实验结果一致。在再生处理（CH ₄条件）期间，PdO颗粒减少，Al ₂（SO ₄）₃被部分除去，并且对CH ₄的活性转化次数增加。由于残留的Al ₂（SO ₄）₃，包封的硫物质的形成以及PdO颗粒的部分还原，因此无法观察到完全回收。为了使Pd再氧化，使催化剂进一步再生（O ₂条件）。所得的CH ₄转化率与再生催化剂的转化率处于相同水平。因此，与Pd的状态相比，少量的Al ₂（SO ₄）₃似乎对性能具有更强的影响。