In this work we present 3 showcases that luminescence thermometry is a promising and versatile technique for temperature monitoring in various microfluidic devices.

In this review article, we discuss the latest advances and future perspectives of microfluidics for micro/ nanoscale catalyst particle synthesis and analysis. In the first section, we present an overview of the different methods to synthesize catalysts making use of microfluidics and in the second section, we critically review catalyst particle characterization using microfluidics. The strengths and challenges of these approaches are highlighted with various showcases selected from the recent literature. In the third section, we give our opinion on the future perspectives of the combination of catalytic nanostructures and microfluidics. We anticipate that in the synthesis and analysis of individual catalyst particles, generation of higher throughput and better understanding of transport inside individual porous catalyst particles are some of the most important benefits of microfluidics for catalyst research. SynthesisThis section focuses on the most recent approaches within the last 8 years. For a more extensive overview of the synthesis of nanostructures focused on the processes taking place inside the microfluidic systems, 5 the final application 4 or the microfluidic technology used 6,7 we refer the reader to other review articles. Metal nanoparticlesMetal nanoparticles exhibit very interesting catalytic, optical, chemical, electromagnetic and magnetic properties, all of them depending to a large degree on their size and composition. Regarding catalysis, a decrease of the NP size leads to a surface-area increase per mass, providing more active sites. Also, the surface structure is of vital importance for the NP selectivity: the presence of steps, edges or terraces in the atomic surface can influence the reaction pathways to Lab Chip, 2019, 19, 3575-3601 | 3575 This journal is

Solid catalysts are complex, multi-component materials with large interparticle heterogeneities that hamper statistically relevant in-depth catalyst characterization. Here we introduce an automated high-throughput screening and sorting method for catalyst particles. A droplet microreactor was developed for fluorescence-activated sorting of catalyst particles using dielectrophoresis. Fluid catalytic cracking (FCC) particles stained with styrene derivatives were analysed with the analytical platform developed and sorted based on catalytic activity. Highly active and low-to-moderately active catalyst particles were sorted using 4-fluorostyrene or 4-methoxystyrene as probe, respectively. FCC particles were encapsulated in liquid droplets, where fluorescent FCC particles activated the dielectrophoretic sorter and were sorted within 200 ms. Post-sorting analysis of 4-fluorostyrene-stained and sorted catalyst particles was done using fluorescence microscopy and micro-X-ray fluorescence. This confirmed that the sorted particles were the least deactivated and showed the highest acidity, while non-sorted particles contained more metal poisons.