TY - JOUR
T1 - Nanoscale Chemical Diversity of Coke Deposits on Nanoprinted Metal Catalysts Visualized by Tip-Enhanced Raman Spectroscopy
AU - Filez, Matthias
AU - Walke, Peter
AU - Le-The, Hai
AU - Toyouchi, Shuichi
AU - Peeters, Wannes
AU - Tomkins, Patrick
AU - Eijkel, Jan C.T.
AU - De Feyter, Steven
AU - Detavernier, Christophe
AU - De Vos, Dirk E.
AU - Uji-I, Hiroshi
AU - Roeffaers, Maarten B.J.
N1 - Publisher Copyright:
© 2023 Wiley-VCH GmbH.
PY - 2024/2/1
Y1 - 2024/2/1
N2 - Coke formation is the prime cause of catalyst deactivation, where undesired carbon wastes block the catalyst surface and hinder further reaction in a broad gamut of industrial chemical processes. Yet, the origins of coke formation and their distribution across the catalyst remain elusive, obstructing the design of coke-resistant catalysts. Here, the first-time application of tip-enhanced Raman spectroscopy (TERS) is demonstrated as a nanoscale chemical probe to localize and identify coke deposits on a post-mortem metal nanocatalyst. Monitoring coke at the nanoscale circumvents bulk averaging and reveals the local nature of coke with unmatched detail. The nature of coke is chemically diverse and ranges from nanocrystalline graphite to disordered and polymeric coke, even on a single nanoscale location of a top-down nanoprinted SiO2-supported Pt catalyst. Surprisingly, not all Pt is an equal producer of coke, where clear isolated coke “hotspots” are present non-homogeneously on Pt which generate large amounts of disordered coke. After their formation, coke shifts to the support and undergoes long-range transport on the surrounding SiO2 surface, where it becomes more graphitic. The presented results provide novel guidelines to selectively free-up the coked metal surface at more mild rejuvenation conditions, thus securing the long-term catalyst stability.
AB - Coke formation is the prime cause of catalyst deactivation, where undesired carbon wastes block the catalyst surface and hinder further reaction in a broad gamut of industrial chemical processes. Yet, the origins of coke formation and their distribution across the catalyst remain elusive, obstructing the design of coke-resistant catalysts. Here, the first-time application of tip-enhanced Raman spectroscopy (TERS) is demonstrated as a nanoscale chemical probe to localize and identify coke deposits on a post-mortem metal nanocatalyst. Monitoring coke at the nanoscale circumvents bulk averaging and reveals the local nature of coke with unmatched detail. The nature of coke is chemically diverse and ranges from nanocrystalline graphite to disordered and polymeric coke, even on a single nanoscale location of a top-down nanoprinted SiO2-supported Pt catalyst. Surprisingly, not all Pt is an equal producer of coke, where clear isolated coke “hotspots” are present non-homogeneously on Pt which generate large amounts of disordered coke. After their formation, coke shifts to the support and undergoes long-range transport on the surrounding SiO2 surface, where it becomes more graphitic. The presented results provide novel guidelines to selectively free-up the coked metal surface at more mild rejuvenation conditions, thus securing the long-term catalyst stability.
KW - 2024 OA procedure
KW - coke formation
KW - nanoparticle catalysts
KW - propane dehydrogenation
KW - reactivation
KW - tailored catalyst fabrication
KW - tip-enhanced Raman spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=85178930967&partnerID=8YFLogxK
U2 - 10.1002/adma.202305984
DO - 10.1002/adma.202305984
M3 - Article
C2 - 37938141
AN - SCOPUS:85178930967
SN - 0935-9648
VL - 36
JO - Advanced materials
JF - Advanced materials
IS - 5
M1 - 2305984
ER -