Trends in the Binding Strength of Surface Species on Nanoparticles: How Does the Adsorption Energy Scale with the Particle Size?

Abstract

Thumbnail image of graphical abstract The binding energy of oxygen on Pd nanoparticles was measured by a direct calorimetric method as a function of the particle size. The reduced dimensionality of the Pd substrate results in two counteracting trends: an increase of the Pd[BOND]O binding strength due to a change of the local configuration of the adsorption site and a strong decrease of the Pd[BOND]O bonding due to the reduction of the cluster size

Kinetics of CO oxidation on palladium using microkinetics coupled with reaction route analysis

“…At such saturation coverage, low sticking coefficient in the range of 0.01 − 0.04 for oxygen has been observed (Klotzer et al, 2001;Tait et al, 2005;Zheng and Altman, 2000;Leisenberger et al, 2000). This prediction is also indicative in a recent study (Peter et al, 2013b) suggesting a low sticking coefficient at saturated coverage of oxygen. In the present study, as a narrow temperature range has been considered for fixed bed experiments, a sticking coefficient of 0.07 has been taken for packed bed experiments under atmospheric conditions.…”

Importance of the oxygen bond strength for catalytic activity in soot oxidation

“…As the exact coverages at reaction conditions are not known, heats of chemisorption corresponding to intermediate coverages have been chosen. For palladium a value of 150 kJ/mol, which corresponds to an intermediate coverage for both Pd(111) and for 4 nm Pd nanoparticles [58], has been selected. For platinum a heat of adsorption of 140 kJ/mol has been selected.…”

Simulation of Near Edge X-ray Absorption Fine Structure (NEXAFS) Measurements of CO on Supported Pd Nanoparticles

“…As shown in Fig. 5a, for a particle having a R TS value of 6.48, CO on the (M, m, s) = (37, 24, 17) for particle A (circles), (19,13,9) for particle B (squares), (8, 6, 4) for particle C (triangles), and (3, 3, 2) for particle D (pluses). All particles have the same R TS = 0.8 and R SS = 2.0 but varying R d .…”

“…For instance, one can employ scanning probes (scanning tunneling microscopy (STM) [1], atomic force microscopy [2]), electron microscopy (X-ray photoemission electron microscopy [3], transmission electron microscopy [4], diffraction (photoelectron diffraction [1]) and scattering techniques (grazing-incidence small angle X-ray scattering [5,6]) to monitor the morphology of the nanoparticles. To probe molecular adsorbates on nanoparticles, one can use STM to monitor their adsorption sites [7], infrared absorption spectroscopy to investigate their vibrational modes at different sites [8], and microcalorimetry to measure their sticking coefficients as well as adsorption energies on the nanoparticles [9]. To determine molecular orientations on nanoparticles, near-edge X-ray absorption fine structure (NEXAFS) is one of the few experimental tools available.…”