Electrochemical Cell for Grazing-Incidence X-ray Absorption Spectroscopic Studies of Low-Loaded Electrodes.

X-ray absorption spectroscopy (XAS) is a powerful technique that provides information about the electronic and local geometric structural properties of newly developed electrocatalysts, especially when it is performed under operating conditions (i.e., ).

Impact of Surface Composition Changes on the CO-Reduction Performance of Au-Cu Aerogels.

Over the past decades, the electrochemical CO-reduction reaction (CORR) has emerged as a promising option for facilitating intermittent energy storage while generating industrial raw materials of economic relevance such as CO. Recent studies have reported that Au-Cu bimetallic nanocatalysts feature a superior CO-to-CO conversion as compared with the monometallic components, thus improving the noble metal utilization. Under this premise and with the added advantage of a suppressed H-evolution reaction due to absence of a carbon support, herein, we employ bimetallic AuCu and AuCu aerogels (with a web thickness ≈7 nm) as CO-reduction electrocatalysts in 0.

Quantification of PEFC Catalyst Layer Saturation via In Silico, Ex Situ, and In Situ Small-Angle X-ray Scattering.

The complex nature of liquid water saturation of polymer electrolyte fuel cell (PEFC) catalyst layers (CLs) greatly affects the device performance. To investigate this problem, we present a method to quantify the presence of liquid water in a PEFC CL using small-angle X-ray scattering (SAXS). This method leverages the differences in electron densities between the solid catalyst matrix and the liquid water filled pores of the CL under both dry and wet conditions.

Spectroscopy vs. Electrochemistry: Catalyst Layer Thickness Effects on Operando/In Situ Measurements.

In recent years, operando/in situ X-ray absorption spectroscopy (XAS) has become an important tool in the electrocatalysis community. However, the high catalyst loadings often required to acquire XA-spectra with a satisfactory signal-to-noise ratio frequently imply the use of thick catalyst layers (CLs) with large ion- and mass-transport limitations. To shed light on the impact of this variable on the spectro-electrochemical results, in this study we investigate Pd-hydride formation in carbon-supported Pd-nanoparticles (Pd/C) and an unsupported Pd-aerogel with similar Pd surface areas but drastically different morphologies and electrode packing densities.

Green chemistry and first-principles theory enhance catalysis: synthesis and 6-fold catalytic activity increase of sub-5 nm Pd and Pt@Pd nanocubes.

Synthesizing metal nanoparticles with fine control of size, shape and surface properties is of high interest for applications such as catalysis, nanoplasmonics, and fuel cells. In this contribution, we demonstrate that the citrate-coated surfaces of palladium (Pd) and platinum (Pt)@Pd nanocubes with a lateral length <5 nm and low polydispersity in shape achieve superior catalytic properties. The synthesis achieves great control of the nanoparticle's physico-chemical properties by using only biogenic reagents and bromide ions in water while being fast, easy to perform and scalable.

Electrochemical Surface Area Quantification, CO Reduction Performance, and Stability Studies of Unsupported Three-Dimensional Au Aerogels versus Carbon-Supported Au Nanoparticles.

The efficient scale-up of CO-reduction technologies is a pivotal step to facilitate intermittent energy storage and for closing the carbon cycle. However, there is a need to minimize the occurrence of undesirable side reactions like H evolution and achieve selective production of value-added CO-reduction products (CO and HCOO) at as-high-as-possible current densities. Employing novel electrocatalysts such as unsupported metal aerogels, which possess a highly porous three-dimensional nanostructure, offers a plausible approach to realize this.

Effect of Cobalt Speciation and the Graphitization of the Carbon Matrix on the CO Electroreduction Activity of Co/N-Doped Carbon Materials.

The electroreduction of carbon dioxide is considered a key reaction for the valorization of CO emitted in industrial processes or even present in the environment. Cobalt-nitrogen co-doped carbon materials featuring atomically dispersed Co-N sites have been shown to display superior activities and selectivities for the reduction of carbon dioxide to CO, which, in combination with H (i.e.

On the Oxidation State of Cu O upon Electrochemical CO Reduction: An XPS Study.

The encouraging selectivity of copper oxides for the electroreduction of CO into ethylene and alcohols has led to a vivid debate on the possible relation between their operando (sub-)surface oxidation state (i. e. fully reduced or partially oxidized) and this distinct reactivity.