Microfluidics and catalyst particles

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

Microfluidics and catalyst particles

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

Microfluidics and catalyst particles

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

Magnethophoretic sorting of fluid catalytic cracking particles

We demonstrate an on-chip particle activity sorter, focused on iron concentration and based on magnetophoresis. This device was used for fast sorting of stepwise homogenously distributed [Fe]s. The preliminary results are very encouraging. We show that we can sort particles on magnetic moment, with a spread of a factor of four. XRF measurements confirm that the spread in magnetic moment is due to an increase in [Fe] concentration. This results fits well with particle trajectory simulations

Concentration Polarization to Measure Nano-pore Accessibility

Understanding the deactivation process in porous catalysts is of tremendous economic significance. We demonstrate the feasibility of using the concentration polarization method to obtain the pore accessibility distribution at single particle level for the first time. By using this technique we could measure the pore blockage caused by Fe in fluid catalytic cracking particles as evidenced by correlating it to the activity. We expect this new single particle technique to increase our understanding of the deactivation processes occurring in porous catalysts

Design and characterization of a microreactor for monodisperse catalytic droplet generation at both elevated temperatures and pressures

We report the fabrication and characterization of a microfluidic droplet microreactor with potential use for single catalyst particle diagnostics. The aim is to capture Fluid Catalytic Cracking (FCC) particles in droplets and perform a probe reaction that results in a fluorescent output signal. The intensity of such a signal can be used as a measure of the catalytic activity of the particle. The microreactor features a droplet generator, platinum (Pt) microheaters, and Pt micro temperature sensors, and is able to operate at pressures up to at least 5 bar. Fluidic channels are etched in a silicon substrate, and platinum heater and sensor structures embedded in the glass cover. We have mapped the temperature inside the microchannels using nanoparticles that show temperature-dependent luminescence. At various spots on the chip, the temperature deviates by 0.86 degrees Celsius close to the Pt sensor and 5.5 degrees Celsius farther away from it. Experiments with making oil-in-water droplets at various temperatures and pressures result in stable droplets up to 100 degrees Celsius at atmospheric pressure. At this temperature, small gas bubbles are formed in the water phase, and then collected by the oil droplets. At a pressure of 5 bar, the droplets are stable up to at least 120 degrees Celsius. E-cat FCC particles were captured in water droplets at a rate of 150 droplets per second

Microfluidics and catalyst particles

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Mimicking industrial aging in fluid catalytic cracking: A correlative microscopy approach to unravel inter-particle heterogeneities

Artificially mimicking aging of an equilibrium catalyst (ECAT) is an effective strategy to model the deactivation of a Fluid Catalytic Cracking (FCC) catalyst during refinery operations. Herein, we have used a correlative microscopy approach to unravel inter-particle spatial heterogeneities in artificially deactivated catalysts (DCATs) and compared them with a real-life ECAT containing on average 3800 ppm of Ni and 2300 ppm of V, and a set of density separated ECAT fractions. By doing so we could rationalize the effect of metal contaminants on catalyst acidity and pore accessibility. More specifically, the Fe, Ni, and V distributions were obtained using X-Ray Fluorescence (XRF), while Confocal Fluorescence Microscopy (CFM) after thiophene and Nile Blue A staining, respectively provided a visualization of Brønsted acid sites and accessibility distribution. We found that not only the metal poisons distribution, but also hydrothermal degradation, that affects ECATs dealumination and related acidity drop, need to be properly reproduced by artificial catalyst deactivation protocols. Fe contamination must also be taken into account since it affects matrix accessibility

Mimicking industrial aging in fluid catalytic cracking: A correlative microscopy approach to unravel inter-particle heterogeneities

Artificially mimicking aging of an equilibrium catalyst (ECAT) is an effective strategy to model the deactivation of a Fluid Catalytic Cracking (FCC) catalyst during refinery operations. Herein, we have used a correlative microscopy approach to unravel inter-particle spatial heterogeneities in artificially deactivated catalysts (DCATs) and compared them with a real-life ECAT containing on average 3800 ppm of Ni and 2300 ppm of V, and a set of density separated ECAT fractions. By doing so we could rationalize the effect of metal contaminants on catalyst acidity and pore accessibility. More specifically, the Fe, Ni, and V distributions were obtained using X-Ray Fluorescence (XRF), while Confocal Fluorescence Microscopy (CFM) after thiophene and Nile Blue A staining, respectively provided a visualization of Brønsted acid sites and accessibility distribution. We found that not only the metal poisons distribution, but also hydrothermal degradation, that affects ECATs dealumination and related acidity drop, need to be properly reproduced by artificial catalyst deactivation protocols. Fe contamination must also be taken into account since it affects matrix accessibility

‘Democracy always comes first’: adolescents’ views on decision-making in everyday life and political democracy

Research shows adolescents to be positively oriented towards democracy, but little is known about what it actually means to them and what their views are on decision-making in both everyday situations and political democracy. To gain insight into these aspects of adolescents’ democratic views, we have interviewed 40 Dutch adolescents from second grade of different types of high school. Potential conflict between various democratic principles prevalent in everyday life situations was discussed and compared to how they view decision-making in political democracy. The results of our qualitative study showed that adolescents’ views on issues concerning collective decision-making in everyday situations are quite rich and reflect different models of democracy (majoritarian, consensual, and deliberative). Moreover, how adolescents deal with tensions between democratic principles in everyday life situations varies. While some adolescents combine several principles (for instance, majority rule as a last resort after trying to find broader consensus), other adolescents tend to strictly focus on only one of these principles. Adolescents’ views on political democracy, however, are rather limited and one-dimensional. Those adolescents who seemed to have a more explicit picture of political democracy often preferred a strict focus on majority rule, neglecting minority interests. KEYWORDS: Political socialization, adolescents, decision-making, democratic views, civic engagemen