Taking a different road: following Ag₂₅ and Au₂₅ cluster activation via in situ differential pair distribution function analysis

Abstract

Synchrotron X-ray total scattering measurements and accompanying pair distribution function (PDF) analyses are an excellent characterization technique to complement both transmission electron microscopy (TEM) and extended X-ray absorption fine structure...

Following the temperature-induced activation of carbon-supported trigonal Pd3 nanoclusters for catalysis

“…† A correlation plot is a mathematical function which offers an easy visualization for tracing changes and similarities in a large dataset. 36 The similarity map was obtained from the Pearson correlation analysis over the R range of 1.5 to 25 Å. The map shows a very high similarity in the dPDF data between 25-125 °C, along with a rapid drop in similarity starting at 150 °C as a result of the activation of the cluster surfaces.…”

“…In the case of supported Au 25 and Ag 25 NCs, we have previously shown that the average size of metal nanoparticles reached 4.9 ± 2.8 nm and 3.2 ± 0.8 nm, respectively, due to sintering at 250 °C. 36 Fig. 3a shows the Pd K edge XANES spectra of Pd 3 @C after treatment at different temperatures, along with Pd, PdO, and Pd(OH) 2 references.…”

“…35,[57][58][59] The Pearson correlation plots were calculated by following a method reported in literature. 36 All X-ray Photoelectron Spectroscopy (XPS) measurements were collected using a Kratos (Manchester, UK) AXIS Supra system at the Saskatchewan Structural Sciences Centre (SSSC) under UHV conditions. This system is equipped with a 500 mm Rowland circle monochromated Al K-α (1486.6 eV) source and combined hemi-spherical analyzer (HSA) and spherical mirror analyzer (SMA).…”

“…34,35 Recently, our research group has used the in situ dPDF analysis to monitor the thermal activation processes of the alumina-supported Au 25 (SR) 18 − and Ag 25 (SR) 18 − NCs for the first time. 36 In this report, we have employed in situ dPDF analysis complemented by ex situ EXAFS, XANES, XPS, and TEM measurements to monitor the speciation and structural evolution of carbon-supported [Pd 3 (μ-Cl)(μ-PPh 2 ) 2 (PPh 3 ) 3 ]Cl NCs (abbreviated here as Pd 3 NCs) during aerobic thermal activation at different temperatures, as shown in Scheme 1.…”

Insights into the growth law, electronic properties and spectra of Fenλ (n = 3–18; λ = 0, ±1) clusters

“…Matter can be divided into different levels, and clusters are a material level between macro and microstructure. As the transition state of various substances from atom and molecule to bulk substances, clusters often show many new phenomena and properties due to the strong quantum confinement effect [1–36] [Correction added after first online publication on August 8, 2023: The second sentence of the Introduction has been updated.]. For example, the Ag 14 cluster has been used to label lung cancer cells due to lower cytotoxicity.…”