Reductive Treatment of Ga-Pt-Supported Catalytically Active Liquid Metal Solutions (SCALMS) for Propane Dehydrogenation

Madubuko N, Hsieh TE, Vorlaufer N, Carl S, Steffen J, Mölkner A, Taccardi N, Frisch J, Wilks RG, Will J, Haumann M, Görling A, Spiecker E, Felfer P, Bär M, Wasserscheid P (2025)

Publication Type: Journal article

Publication year: 2025

Journal

ACS Catalysis American Chemical Society

Pages Range: 12436-12449

DOI: 10.1021/acscatal.5c01463

Abstract

A comprehensive investigation of the impact of hydrogen (H2) pretreatments on Ga-Pt supported catalytic active liquid metal solution (SCALMS) for propane dehydrogenation (PDH) is reported. Our approach bridges from model system investigations to real-world catalytic systems, which are tested in continuously operating PDH reactors. The microscopic and spectroscopic findings on model Ga-Pt systems suggest changes in the electronic structure and surface chemistry during SCALMS sample oxidation and H2 pretreatment, indicating potential modifications of the active sites involved in PDH. H2 pretreatments of technical Ga-Pt SCALMS prepared by ultrasonication (US) led to significantly improved activity, i.e., the conversion of propane increased from 10% for the untreated catalyst to 26% for the H2 pretreated (5 h at 823 K) catalyst. We attribute this enhanced activity to the removal of a gallium oxide (GaOx) shell, as confirmed by synchrotron-based in situ X-ray photoelectron spectroscopy (XPS) as well as in situ transmission electron microscopy (TEM) investigations of Ga-Pt model alloys. These findings are supported by density functional theory (DFT) and machine learned force field (ML-FF) calculations. Increasing the temperature of the H2 treatment to 923 K reduced the deactivation rate of the catalyst to as low as 0.01 h-1, which is 3 times more stable than what was observed for the untreated catalyst. This deactivation is ascribed to bulk restructuring of the alloy, leading to the formation of less active Pt species as confirmed by spectroscopic and microscopic analysis. Our work not only elucidates the fundamental properties, i.e., typology, electronic structure, and reactivity, of isolated Pt atoms in Ga-Pt SCALMS but also proposes underlying mechanisms for the activation and deactivation of PDH catalysts.

Authors with CRIS profile

Nnamdi Madubuko Lehrstuhl für Chemische Reaktionstechnik (CRT) Nora Vorlaufer Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften) Simon Carl Lehrstuhl für Werkstoffwissenschaften (Mikro- und Nanostrukturforschung) Julien Steffen Lehrstuhl für Theoretische Chemie Andreas Mölkner Lehrstuhl für Theoretische Chemie Nicola Taccardi Lehrstuhl für Chemische Reaktionstechnik (CRT) Johannes Will Lehrstuhl für Werkstoffwissenschaften (Mikro- und Nanostrukturforschung) Marco Haumann Lehrstuhl für Chemische Reaktionstechnik (CRT) Andreas Görling Lehrstuhl für Theoretische Chemie Erdmann Spiecker Peter Felfer Professur für Atom Probe Tomography Marcus Bär
Peter Wasserscheid Lehrstuhl für Chemische Reaktionstechnik (CRT)

Involved external institutions

Helmholtz-Zentrum Berlin für Materialien und Energie (HZB) DE Germany (DE)

How to cite

APA:

Madubuko, N., Hsieh, T.E., Vorlaufer, N., Carl, S., Steffen, J., Mölkner, A.,... Wasserscheid, P. (2025). Reductive Treatment of Ga-Pt-Supported Catalytically Active Liquid Metal Solutions (SCALMS) for Propane Dehydrogenation. ACS Catalysis, 12436-12449. https://doi.org/10.1021/acscatal.5c01463

MLA:

Madubuko, Nnamdi, et al. "Reductive Treatment of Ga-Pt-Supported Catalytically Active Liquid Metal Solutions (SCALMS) for Propane Dehydrogenation." ACS Catalysis (2025): 12436-12449.

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