TY - JOUR

T1 - Impact of nanoparticle exsolution on dry reforming of methane

T2 - Improving catalytic activity by reductive pre-treatment of perovskite-type catalysts

AU - Schrenk, Florian

AU - Lindenthal, Lorenz

AU - Drexler, Hedda

AU - Urban, G.

AU - Rameshan, Raffael

AU - Summerer, Harald

AU - Berger, Tobias

AU - Ruh, Thomas

AU - Opitz, Alexander Karl

AU - Rameshan, Christoph

N1 - Publisher Copyright: © 2022 The Authors

PY - 2022/12/5

Y1 - 2022/12/5

N2 - Nanoparticle exsolution is regarded as a promising alternative to classical catalyst synthesis routes. In this work, we compare the catalytic performance of nanoparticles formed by in-situ exsolution during dry reforming of methane with particles pre-formed by reductive pre-treatment. The experiments were conducted on three perovskite-type oxides. Using a combination of in-situ and operando spectroscopic investigations (x-ray diffraction, near ambient pressure x-ray photoelectron spectroscopy) and the correlation to the obtained catalytic results, we could highlight that pre-formed nanoparticles strongly enhance the activity compared to in-situ exsolution. Scanning electron microscope images recorded after catalytic tests revealed that nanoparticles formed during reductive pre-treatment are bigger on average than particles formed in-situ. Furthermore, B-site doping with Co or Ni significantly enhanced the catalytic activity. Importantly, the perovskite host lattice was stable in all experiments, thus providing the necessary enhanced oxygen surface chemistry which is the key to the coking resistance of the investigated materials. Additionally, we observe a temperature dependent change of mechanism leading to different product ratios.

AB - Nanoparticle exsolution is regarded as a promising alternative to classical catalyst synthesis routes. In this work, we compare the catalytic performance of nanoparticles formed by in-situ exsolution during dry reforming of methane with particles pre-formed by reductive pre-treatment. The experiments were conducted on three perovskite-type oxides. Using a combination of in-situ and operando spectroscopic investigations (x-ray diffraction, near ambient pressure x-ray photoelectron spectroscopy) and the correlation to the obtained catalytic results, we could highlight that pre-formed nanoparticles strongly enhance the activity compared to in-situ exsolution. Scanning electron microscope images recorded after catalytic tests revealed that nanoparticles formed during reductive pre-treatment are bigger on average than particles formed in-situ. Furthermore, B-site doping with Co or Ni significantly enhanced the catalytic activity. Importantly, the perovskite host lattice was stable in all experiments, thus providing the necessary enhanced oxygen surface chemistry which is the key to the coking resistance of the investigated materials. Additionally, we observe a temperature dependent change of mechanism leading to different product ratios.

KW - CO utilisation

KW - Coke resistance

KW - Exsolution

KW - in-situ NAP-XPS

KW - Perovskite

UR - http://www.scopus.com/inward/record.url?scp=85136575148&partnerID=8YFLogxK

U2 - 10.1016/j.apcatb.2022.121886

DO - 10.1016/j.apcatb.2022.121886

M3 - Article

AN - SCOPUS:85136575148

VL - 318.2022

JO - Applied Catalysis B: Environmental

JF - Applied Catalysis B: Environmental

SN - 0926-3373

IS - 5 December

M1 - 121886

ER -