Chemical industries are currently undergoing a historical transformation to drive the energy transition towards utilization of more bio or waste-based feedstocks to produce more sustainable chemicals and fuels. Designing new and adapting existing heterogeneous catalysts to allow different chemical conversion reactions is one of the imperatives to support this transition.
It is well established that the performance of a catalyst is greatly dependent on an intimate interplay of morphological and chemical properties from macro- to the nanoscale. Most notably, catalyst particle size, shape or composition (e.g. metal, oxide, sulfide, bimetallic), catalyst particle interaction with the support and accessibility through often complex porous networks within the support, are key parameters in determining the catalytic activity and selectivity. Hydrotreating catalysts are a prime example of complex catalyst systems. These catalysts consist of mixed metal sulfide Ni-Mo nanoparticles, which are dispersed on a high-surface area support material. NiMoS slabs (MoS2 structure type) occur in various sizes, degrees of stacking and interactions with the support material. Not rarely do these catalysts display a catalytic performance that is hard to explain by bulk properties; a detailed investigation of their nano/atomic structure to explain performance is called for. During the energy transition these catalysts may be utilized in a broader range of applications, especially in processing feedstocks other than those derived from crude oil, which might require re-engineering catalyst systems. It is thus of pivotal interest to close gaps in structure-activity relations and prompting this project to employ state-of-the-art electron microscopy tools to study the relationship between synthesis, structure and performance.