Example on the Use of Operando Spectroscopy for Developing Mechanistic Insights into Industrial Catalysts and Catalytic Processes

In this contribution, we present an industrial example on how tailored operando spectroscopic methodologies provide the insights needed for the development of new catalytic technologies and support their global utilization. We describe the use of operando spectroscopic methods to investigate how the CO oxidation performance of catalysts is impacted by NOx, H2, temperature, and moisture, as well as the catalyst support. This operando spectroscopic analysis provides mechanistic insights into the current diesel oxidation catalyst (DOC) system and shines light on the material and process development efforts on future DOC catalysts for low-temperature emission control to meet the new regulations. This investigation has shown that at cold-start temperatures, the nitrate growth can occupy the precious metal–alumina support interfacial sites that are critical for O2 dissociation and/or oxygen transfer and hinder CO conversion. Introduction of hydrogen on the catalyst surface can inhibit the nitrate growth, which in turn keeps these critical interfacial sites open.