Unravelling the Formation of Pt–Ga Alloyed Nanoparticles on Calcined Ga-Modified Hydrotalcites by in Situ XAS

Abstract

An optimal balance between a reasonable k-and R-space resolution should be obtained in order to adequately pinpoint the k-region of backscattering for each specific R-space peak.

The role of hydrogen during Pt–Ga nanocatalyst formation

“…1f): the white line intensity decreases and the edge shifts to higher energies. 36,39,40 The white line intensity decreases due to Pt reduction, as confirmed by the reduction of Ga-free Pt/Mg(Al)O x reference ( Fig. 1d), while the edge shifts due to Pt-Ga alloying.…”

“…In addition to the significant industrial relevance of Pt-Ga catalysts in general, 32,33 these specific materials present a convenient fundamental model system for studying H-spillover and nano-alloying in catalysis. Recently, a comprehensive characterization of these catalysts as well as their Pt-In and Pt-Sn analogs has been performed by our group 22,[34][35][36][37][38][39][40] and others. [19][20][21]41 The reduction of framework Ga 3+ is a highlyactivated process, characterized by much higher transition temperatures than the reduction of other reducible metal ions such as Cu and Ni 42 or Pd and Zn 26 in LDH-derived frameworks.…”

Zinc influence on the formation and properties of Pt/Mg(Zn)AlO catalysts synthesized from layered hydroxides

“…It should be noted that, unlike in the works [16][17][18][19][20][21][54][55][56] where platinum was anchored by impregnation of the calcined LDH with toluene solutions of acetylacetonate platinum, in this study the maximum interaction of platinum with the modifying cation was provided by platinum anchoring via intercalation of Pt(IV) anionic chloride complexes into the interlayer space of zinc-containing LDH. This anchoring method made it possible to use aqueous solutions of the metal complex.…”

Formation and Functioning of Bimetallic Nanocatalysts: The Power of X‐ray Probes

“…In situ GISAXS showed NP growth during Pt-In alloying (lobe shift to smaller q y and q z values, Figure 6c,d), with subsequent NP height increase upon further heating (secondary lobe shift to smaller q z ). Filez et al [65,66] further detailed the alloying process as follows: i) dissociation of H 2 on Pt, ii)Hspillover to and iii)long-range transport across the support, iv) (partial) reduction of indium oxide by H, v) short-range transport to Pt, followed by vi)full reduction to In 0 and (vii)Pt-In alloying.…”