Decomposition of PdSO₄, a species responsible for the deactivation of Pd-based methane combustion catalysts, was studied using a PdSO₄/Al₂O₃ model system. PdSO₄ was observed to behave differently under different reaction conditions. The decomposition of PdSO₄ under inert atmosphere probably involved only one reaction step and resulted in the formation of metallic palladium. Under H₂-containing atmosphere, the decomposition of PdSO₄ resulted eventually in the formation of Pd₄S, which is probably one of the many possible sulfur-containing palladium species that can be formed during regeneration of a sulfur-poisoned Pd-rich methane combustion catalyst. The formation of Pd₄S can provide a reasonable explanation to the threshold temperature of sulfur removal from the catalyst, as well as to the residual sulfur present in the catalyst after regeneration under reductive atmosphere. Overall, the results obtained in the study provide deeper insight into the regeneration process of Pd-based catalysts, possibly enabling development of a more efficient regeneration strategy.

使用PdSO ₄ / Al ₂ O ₃模型系统研究了负责使Pd基甲烷燃烧催化剂失活的物质PdSO _4的分解。观察到PdSO ₄在不同反应条件下的行为不同。PdSO ₄在惰性气氛下的分解可能仅涉及一个反应步骤，并导致金属钯的形成。在含H ₂的气氛下，PdSO ₄的分解最终导致Pd ₄的形成S，可能是在硫中毒的富含Pd的甲烷燃烧催化剂再生过程中可能形成的许多可能的含硫钯物质之一。Pd ₄ S的形成可以合理解释从催化剂脱硫的阈值温度，以及还原性气氛下再生后催化剂中残留的硫。总体而言，研究中获得的结果为Pd基催化剂的再生过程提供了更深刻的见解，可能使开发更有效的再生策略成为可能。