Aberration‐Corrected Imaging of Active Sites on Industrial Catalyst Nanoparticles

Abstract

Picture perfect: Information about the local topologies of active sites on commercial nanoparticles can be gained with atomic resolution through spherical‐aberration‐corrected transmission electron microscopy (TEM). A powder of Pt nanoparticles on carbon black was examined with two advanced TEM techniques based on recent developments in hardware (aberration correction) and computation (exit wavefunction restoration).

Atomic-Scale Modeling of Particle Size Effects for the Oxygen Reduction Reaction on Pt

“…A step was assumed to be created at each of the adjacent facets. Recent advances in electron microscopy have allowed for the direct observation of the atomic structure of the surface of nanoparticles [13,14], supporting the presence of defects in the form that our particle model assumes. We ignored the effect of the support on the morphology of the particle [15], and we assumed no surface restructuring during the reaction.…”

Applications of the Oxford-JEOL aberration-corrected electron microscope

“…To illustrate the potential benefits of a combined direct / indirect approach to aberration correction and compensation, Figure 2(a) shows the phase of the specimen exit surface wavefunction of a Pt catalyst nanoparticle, viewed close to a <110> direction reconstructed from a focal series of aberration corrected images acquired using the OJ1 instrument [9]. Despite the presence of a partially graphitic carbon support, terraces and steps at the edge of the particle are visible and moreover, the visibility, and spatial resolution of these features are improved significantly compared to a conventional HRTEM image.…”

Synthesis and characterization of Pt–Pd nanoparticles with core-shell morphology: Nucleation and overgrowth of the Pd shells on the as-prepared and defined Pt seeds

“…Moreover, their catalytic and electrocatalytic critical properties are tuned by controlling in both the size and the morphology. It is known that the morphologies of {1 1 1}, {1 0 0}, and {1 1 0} low-index planes or facets of Pt nanoparticles are very important in the selective catalytic reactions [5][6][7][8]. The general methods of chemically synthesizing Pt nanoparticles are utilized in a bottom-up approach in the reduction of their salts with suitable reducing agents and stabilizers, such as K 2 PtCl 4 (potassium plantinum(II) chloride) [9,10], Na 2 PtCl 4 (sodium tetrachloroplatinate(II) hydrate) [3], H 2 PtCl 6 (dihyrogen hexachroplatinate(IV) hexahydrate), Pt(acac) 2 (platinum(II) acetylacetonate), and their ligands [3,11].…”