Abstract
Exsolution of surface and bulk nanoparticles in perovskites has been recently employed in chemical looping methane partial oxidation because of the emergent materials’ properties such as oxygen capacity, redox stability, durability, coke resistance and enhanced activity. Here we attempt to further lower the temperature of methane conversion by complementing exsolution with infiltration. We prepare an endo/exo-particle system using exsolution and infiltrate it with minimal amount of Rh (0.1 wt%) in order to functionalize the surface and induce low temperature activity. We achieve a temperature decrease by almost 220 °C and an increase of the activity up to 40%. We also show that the initial microstructure of the perovskite plays a key role in controlling nanoparticle anchorage and carbon deposition. Our results demonstrate that microstructure tuning and surface functionalization are important aspects to consider when designing materials for redox cycling applications.
Highlights
Chemical looping (CL), originally implemented in the steam-iron process, was initially employed for hydrogen production via the water gas shift reaction [1]
In order to exsolve the exo/endo-particles, we reduced the samples at 1000 ◦ C (10 h) and we label them with an -Ni suffix, indicating the presence of such particles, i.e., fine powder (fP)-Ni, coarse powder (cP)-Ni, pP-Ni
In this work we demonstrate the effect of the microstructure upon the exsolution process as well as on the activity of the exsolved exo/endo-particle systems
Summary
Chemical looping (CL), originally implemented in the steam-iron process, was initially employed for hydrogen production via the water gas shift reaction [1]. CL has recently received a lot of attention due to benefits related to inherent product separation that result in more efficient and safer processes [2,3,4]. Material requirements for CL processes have proven to be quite complex especially when applied for hydrocarbon conversion, e.g., methane. Material design needs to take into account both bulk transport properties and surface catalytic activity [5,6,7]. Surface activity and selectivity towards the conversion of methane to syngas [8], preferably at low temperatures, are essential
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
