Mapping metal catalysts using synchrotron computed microtomography (CMT) and micro-X-ray fluorescence (μXRF)

Abstract

Gas-to-liquids (GTL) is a viable pathway to synthesize clean fuels from natural gas. The continuing technological advances in natural gas conversion technology have led several companies to make investment in the Fischer–Tropsch (F–T) route to synthesize clean hydrocarbon fuels. But, a highly efficient gas conversion process to capitalize on remote natural gas fields still remains elusive. Heterogeneous catalyst assemblies are typically utilized in the GTL conversion reactions but an in-depth characterization of catalytic materials is needed to design the next-generation more efficient catalysts. Computed microtomography (CMT) and micro-X-ray fluorescence (μXRF), techniques at the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory (BNL), are complementary methods that allow mapping of catalyst constituents. We describe here the experimental apparatus and give examples of utilization of these techniques in catalyst characterization in different processes. The potential of using CMT and μXRF techniques for monitoring changes in the catalyst composition during F–T synthesis are discussed and an example based on the use of X-ray fluorescence imaging is presented.