Ga–Pt supported catalytically active liquid metal solutions (SCALMS) prepared by ultrasonication – influence of synthesis conditions onn-heptane dehydrogenation performance

Abstract

The preparation of supported catalytically active metal solutions has been investigated using ultrasonication. Sonication conditions and solvents influence the Ga droplet formation and hence the catalytic performance in heptane dehydrogenation.

Implications of Ga promotion and metal–oxide interface from tailored PtGa propane dehydrogenation catalysts supported on carbon

“…This suggests, that the difference in deactivation behavior between Pt 0.89 Ga 1.00 _Si 1.64 /C H 2 and Pt 0.26 Ga 0.10 /C H 2 could be related to the higher Pt to Ga ratio (0.3 vs. 0.5) of the Pt 0.26 Ga 0.10 /C H 2 catalyst, rather than an effect caused by the presence of an oxide interface, as recently suggested in PtGa based dehydrogenation of n -heptane. 21 Overall, when comparing the initial propene productivity of the silicate decorated Pt 0.15 Ga 0.10 _Si 0.31 /C H 2 (904 g C 3 H 6 /(g Pt h); 4192 mol C 3 H 6 /(mol Pt h)) to the purely carbon-supported Pt 0.26 Ga 0.10 /C H 2 (486 g C 3 H 6 /(g Pt h); 2254 mol C 3 H 6 /(mol Pt h)) catalyst, an enhanced initial propene productivity is observed, likely as a result of the presence of an oxide interface (Table 2 and Fig. S4†).…”

Kinetics of dehydrogenation of n-heptane over GaPt supported catalytically active liquid metal solutions (SCALMS)

“…32 More recently, we have studied effect of the synthesis parameters of GaPt SCALMS via ultrasonication on the rate of the galvanic displacement, thus on the morphology of the GaPt nanocomposites, and on the catalytic performance of the resulting materials in n-heptane dehydrogenation. 33 Under reaction conditions, dopant active metal atoms exist as isolated homogeneous sites in the much less reactive liquid metal matrix and are considered to be analogous to single-atom alloys (SAAs). 24 The properties of SCALMS are linked to the unique dynamic interface and modified electronic properties of isolated active metal atoms in the Ga matrix, 26 which enhances its activity.…”

Structural Evolution of GaOx-Shell and Intermetallic Phases in Ga–Pt Supported Catalytically Active Liquid Metal Solutions

“…To gain structural insights into the microscopic properties and processes of SCALMS and their role for the catalytic performance, different experimental approaches have been pursued. On the one hand, model SCALMS systems have been prepared as macroscopic bulk alloy droplets or thin particle films on flat substrates/membranes , and have been studied using X-ray photoelectron spectroscopy (XPS) and analytical transmission electron microscopy (TEM). , These studies provided insights into surface segregation of the active metal, precipitation/dissolution of intermetallic phases (IPs), and oxide shell formation as a function of temperature under well-controlled conditions . On the other hand, real operational SCALMS systems have been studied using scale-bridging three-dimensional (3D) characterization workflows to analyze the 3D distribution of SCALMS particles on and within the porous support.…”

“…The Ga–Pt SCALMS catalyst was prepared by using the US method. This involves the breakdown of a large 1 g Ga nugget (99.9999%; Alfa Aesar) by US into nanodroplets in propane-2-ol (99.8%; Jäkle Chemie) with particle size distribution ranging from a few nanometers to several micrometers. , The formed Ga dispersion is deposited onto a porous trisopor glass particle (∼200–300 μm in size). Using a rotary evaporator at 313 K and 0.007 MPa, the solvent propan-2-ol is removed, leaving the formed Ga/trisopor glass.…”

“…1−4 For instance, the Ga−Pt system studied in the present work exhibits outstanding catalytic performance in propane dehydrogenation (PDH). 4 These excellent properties of SCALMS systems have been attributed to the highly dynamic nature of the liquid metal surface which provides sites for single-atom catalysis by diffusion of single Pt atoms to the surface followed by instantaneous renewal of the surface due to its highly dynamic nature. 5,6 This proposed SCALMS mechanism has been supported by density functional theory (DFT) calculations; 5 however, further experimental work is necessary to prove the concept under realistic conditions of real SCALMS systems.…”