TY - JOUR

T1 - In Situ Growth of Exsolved Nanoparticles under Varying rWGS Reaction Conditions

T2 - A Catalysis and Near Ambient Pressure-XPS Study

AU - Lindenthal, Lorenz

AU - Huber, Joel

AU - Drexler, Hedda

AU - Ruh, Thomas

AU - Rameshan, Raffael

AU - Schrenk, Florian

AU - Löffler, Stefan

AU - Rameshan, Christoph

N1 - Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2021/12/3

Y1 - 2021/12/3

N2 - Perovskite-type oxides are highly flexible materials that show properties that are beneficial for application in reverse water-gas shift processes (rWGS). Due to their stable nature, the ability to incorporate catalytically active dopants in their lattice structure, and the corresponding feature of nanoparticle exsolution, they are promising candidates for a materials design approach. On an industrial level, the rWGS has proven to be an excellent choice for the efficient utilisation of CO2 as an abundant and renewable carbon source, reflected by the current research on novel and improved catalyst materials. In the current study, a correlation between rWGS reaction environments (CO2 to H2 ratios and temperature), surface morphology, and catalytic activity of three perovskite catalysts (Nd0.6Ca0.4Fe0.9Co0.1O3-δ, Nd0.6Ca0.4Fe0.97Co0.03O3-δ, and Nd0.6Ca0.4Fe0.97Ni0.03O3-δ) is investigated, combining catalytic measurements with SEM and NAP-XPS. The materials were found to react dynamically to the conditions showing both activation due to in situ nanoparticle exsolution and deactivation via CaCO3 formation. This phenomenon could be influenced by choice of material and conditions: less reductive conditions (larger CO2 to H2 or lower temperature) lead to smaller exsolved particles and reduced carbonate formation. However, the B-site doping was also important; only with 10% Co-doping, a predominant activation could be achieved.

AB - Perovskite-type oxides are highly flexible materials that show properties that are beneficial for application in reverse water-gas shift processes (rWGS). Due to their stable nature, the ability to incorporate catalytically active dopants in their lattice structure, and the corresponding feature of nanoparticle exsolution, they are promising candidates for a materials design approach. On an industrial level, the rWGS has proven to be an excellent choice for the efficient utilisation of CO2 as an abundant and renewable carbon source, reflected by the current research on novel and improved catalyst materials. In the current study, a correlation between rWGS reaction environments (CO2 to H2 ratios and temperature), surface morphology, and catalytic activity of three perovskite catalysts (Nd0.6Ca0.4Fe0.9Co0.1O3-δ, Nd0.6Ca0.4Fe0.97Co0.03O3-δ, and Nd0.6Ca0.4Fe0.97Ni0.03O3-δ) is investigated, combining catalytic measurements with SEM and NAP-XPS. The materials were found to react dynamically to the conditions showing both activation due to in situ nanoparticle exsolution and deactivation via CaCO3 formation. This phenomenon could be influenced by choice of material and conditions: less reductive conditions (larger CO2 to H2 or lower temperature) lead to smaller exsolved particles and reduced carbonate formation. However, the B-site doping was also important; only with 10% Co-doping, a predominant activation could be achieved.

KW - Doping

KW - Exsolution

KW - Nanoparticles

KW - Perovskites

KW - Reverse water-gas shift

UR - http://www.scopus.com/inward/record.url?scp=85120654952&partnerID=8YFLogxK

U2 - 10.3390/catal11121484

DO - 10.3390/catal11121484

M3 - Article

AN - SCOPUS:85120654952

VL - 11.2021

JO - Catalysts

JF - Catalysts

SN - 2073-4344

IS - 12

M1 - 1484

ER -