Tracking S poisoning of mono-/bimetallic Pd-based catalysts for CH4 removal by operando tender X-ray HERFD-XANES measurements

Pd-based catalysts are known to show the highest performance during the reduction of methane emissions, while their stability is improved by using Pd-Pt bimetallic systems. However, their application in technical systems is challenged due to their high sulfur poisoning sensitivity. By conducting systematic operando HERFD-XANES measurements at the Pd L3-edge, this study aims at obtaining new insights into the subtle changes in the electronic and chemical state of the noble metal in Pd/Al2O3 and PdPt/Al2O3 methane oxidation catalysts during the S-poisoning and reductive regeneration.[4] The outcome of the spatially resolved investigations is of high relevance for both the scientific and industrial community considering the broad impact of S-poisoning on various noble metal-based catalytic systems.