Cu-Ag interactions in bimetallic Cu-Ag catalysts enhance C product formation during electrochemical CO reduction.

The electroreduction of CO (CORR) is a promising alternative to the direct CO electroreduction reaction (CO2RR) to produce C products. Cu-based electrocatalysts enable the formation of C-C bonds, leading to various C hydrocarbon and oxygenate products. Herein, we investigated how the composition of bimetallic Cu-Ag catalysts impacted the nature of the Cu-Ag interactions and the product distribution of the CORR, aiming to improve the selectivity to C products.

Hyperspectral full-field quick-EXAFS imaging at the ROCK beamline for monitoring micrometre-sized heterogeneity of functional materials under process conditions.

Full-field transmission X-ray microscopy has been recently implemented at the hard X-ray ROCK-SOLEIL quick-EXAFS beamline, adding micrometre spatial resolution to the second time resolution characterizing the beamline. Benefiting from a beam size versatility due to the beamline focusing optics, full-field hyperspectral XANES imaging has been successfully used at the Fe K-edge for monitoring the pressure-induced spin transition of a 150 µm × 150 µm Fe(o-phen)(NCS) single crystal and the charge of millimetre-sized LiFePO battery electrodes. Hyperspectral imaging over 2000 eV has been reported for the simultaneous monitoring of Fe and Cu speciation changes during activation of a FeCu bimetallic catalyst along a millimetre-sized catalyst bed.

Structural Changes of Ni and Ni-Pt Methane Steam Reforming Catalysts During Activation, Reaction, and Deactivation Under Dynamic Reaction Conditions.

Ni-based catalysts are the most widely used materials to produce H in large-scale methane steam reformers under stationary conditions. For domestic applications such as fuel cells, H production involves the exposure of the catalysts to more dynamic conditions due to the daily startup and shutdown operation mode, making Ni-based catalysts susceptible to oxidation and deactivation. In this context, we report a systematic investigation of the structural changes occurring for monometallic Ni/MgAlO and bimetallic NiPt/MgAlO catalysts during methane steam reforming under transient conditions, comprising catalyst activation, operation, and deactivation processes.

Mechanism of formation of Co-Ru nanoalloys: the key role of Ru in the reduction pathway of Co.

The chemical synthesis of alloy nanoparticles requires adequate conditions to enable co-reduction instead of separate reduction of the two metal cations. The mechanism of formation of bimetallic cobalt-ruthenium nanoalloys by reducing metal salts in an alcohol medium was explored to draw general rules to extrapolate to other systems. The relative kinetics of the reduction of both metal cations were studied by UV-visible and Quick-X-ray absorption spectroscopies as well as H evolution.

Isolation and characterization of fourteen polymorphic microsatellite markers in the viperine snake .

Nineteen polymorphic microsatellite loci were identified and developed for . Polymorphism was assessed for 120 individuals sampled across four sampling sites from the French Pyrenees Mountains. The number of alleles per locus ranged from 3 to 15, and expected heterozygosity per locus ranged from 0.

Intra-specific variability of hindlimb length in the palmate newt: an indicator of population isolation induced by habitat fragmentation?

Habitat fragmentation is one of the main drivers of global amphibian decline. Anthropogenic landscape elements can act as barriers, hindering the dispersal that is essential for maintaining gene flow between populations. Dispersal ability can be influenced by locomotor performance, which in turn can depend on morphological traits, such as hindlimb length (HLL) in amphibians.

Microsecond time-resolved energy-dispersive EXAFS measurement and its application to film the thermolysis of (NH₄)₂[PtCl₆].

Microsecond (μs) time-resolved extended X-ray absorption fine structure spectroscopy (EXAFS) has been developed using an energy-dispersive EXAFS (EDE) setup equipped with a silicon Quantum Detector ULTRA. The feasibility was investigated with a prototypical thermally driven redox reaction, the thermal decomposition of (NH₄)₂[PtCl₆]. EXAFS data were collected with snapshots every 60 μs during the course of the thermolysis reaction, then averaged for 100 times along the reaction to get better signal to noise ratio which reduces the time resolution to 6 millisecond (ms).

A high-temperature furnace for in situ synchrotron X-ray spectroscopy under controlled atmospheric conditions.

A high-temperature furnace with an induction heater coil has been designed and constructed for in situ X-ray spectroscopic experiments under controlled atmospheric conditions and temperatures up to 3275 K. The multi-purpose chamber design allows working in backscattering and normal fluorescence mode for synchrotron X-ray absorption and emission spectroscopy. The use of the furnace is demonstrated in a study of the in situ formation of Cr oxide between 1823 K and 2023 K at logPO(2) values between -10.

Pulsed laser deposition chamber for in situ X-ray diffraction.

A sample chamber has been constructed for studying the growth of thin films by pulsed laser deposition in situ with surface X-ray diffraction. The achievable temperature ranges from room temperature to 1073 K in a controlled oxygen environment. The partial pressure of the oxygen background gas covers the range from 0.