Effect of Iron Doping in Ordered Nickel Oxide Thin Film Catalyst for the Oxygen Evolution Reaction.

Water splitting has emerged as a promising route for generating hydrogen as an alternative to conventional production methods. Finding affordable and scalable catalysts for the anodic half-reaction, the oxygen evolution reaction (OER), could help with its industrial widespread implementation. Iron-containing Ni-based catalysts have a competitive performance for the use in commercial alkaline electrolyzers.

Operando Raman spectroscopy uncovers hydroxide and CO species enhance ethanol selectivity during pulsed CO electroreduction.

Pulsed CO electroreduction (CORR) has recently emerged as a facile way to in situ tune the product selectivity, in particular toward ethanol, without re-designing the catalytic system. However, in-depth mechanistic understanding requires comprehensive operando time-resolved studies to identify the kinetics and dynamics of the electrocatalytic interface. Here, we track the adsorbates and the catalyst state of pre-reduced CuO nanocubes ( ~ 30 nm) during pulsed CORR using sub-second time-resolved operando Raman spectroscopy.

Enhanced Methanol Synthesis from CO Hydrogenation Achieved by Tuning the Cu-ZnO Interaction in ZnO/CuO Nanocube Catalysts Supported on ZrO and SiO.

The nature of the Cu-Zn interaction and especially the role of Zn in Cu/ZnO catalysts used for methanol synthesis from CO hydrogenation are still debated. Migration of Zn onto the Cu surface during reaction results in a Cu-ZnO interface, which is crucial for the catalytic activity. However, whether a Cu-Zn alloy or a Cu-ZnO structure is formed and the transformation of this interface under working conditions demand further investigation.

Revealing the Intrinsic Restructuring of BiO Nanoparticles into Bi Nanosheets during Electrochemical CO Reduction.

Bismuth is a catalyst material that selectively produces formate during the electrochemical reduction of CO. While different synthesis strategies have been employed to create electrocatalysts with better performance, the restructuring of bismuth precatalysts during the reaction has also been previously reported. The mechanism behind the change has, however, remained unclear.

insights into correlating CO coverage and Cu-Au alloying with the selectivity of Au NP-decorated CuO nanocubes during the electrocatalytic CO reduction.

Electrochemical reduction of CO (CORR) is an attractive technology to reintegrate the anthropogenic CO back into the carbon cycle driven by a suitable catalyst. This study employs highly efficient multi-carbon (C) producing CuO nanocubes (NCs) decorated with CO-selective Au nanoparticles (NPs) to investigate the correlation between a high CO surface concentration microenvironment and the catalytic performance. Structure, morphology and near-surface composition are studied X-ray absorption spectroscopy and surface-enhanced Raman spectroscopy, high-energy X-ray diffraction as well as quasi X-ray photoelectron spectroscopy.

Spatially and Chemically Resolved Visualization of Fe Incorporation into NiO Octahedra during the Oxygen Evolution Reaction.

The activity of Ni (hydr)oxides for the electrochemical evolution of oxygen (OER), a key component of the overall water splitting reaction, is known to be greatly enhanced by the incorporation of Fe. However, a complete understanding of the role of cationic Fe species and the nature of the catalyst surface under reaction conditions remains unclear. Here, using a combination of electrochemical cell and conventional transmission electron microscopy, we show how the surface of NiO electrocatalysts, with initially well-defined surface facets, restructures under applied potential and forms an active NiFe layered double (oxy)hydroxide (NiFe-LDH) when Fe ions are present in the electrolyte.

Unraveling surface structures of gallium promoted transition metal catalysts in CO hydrogenation.

Gallium-containing alloys have recently been reported to hydrogenate CO to methanol at ambient pressures. However, a full understanding of the Ga-promoted catalysts is still missing due to the lack of information about the surface structures formed under reaction conditions. Here, we employed near ambient pressure scanning tunneling microscopy and x-ray photoelectron spectroscopy to monitor the evolution of well-defined Cu-Ga surfaces during CO hydrogenation.

Shape-Dependent CO Hydrogenation to Methanol over CuO Nanocubes Supported on ZnO.

The hydrogenation of CO to methanol over Cu/ZnO-based catalysts is highly sensitive to the surface composition and catalyst structure. Thus, its optimization requires a deep understanding of the influence of the pre-catalyst structure on its evolution under realistic reaction conditions, including the formation and stabilization of the most active sites. Here, the role of the pre-catalyst shape (cubic vs spherical) in the activity and selectivity of ZnO-supported Cu nanoparticles was investigated during methanol synthesis.

Highly Stable and Reactive Platinum Single Atoms on Oxygen Plasma-Functionalized CeO Surfaces: Nanostructuring and Peroxo Effects.

Atomically dispersed precious metals on oxide supports have recently become increasingly interesting catalytic materials. Nonetheless, their non-trivial preparation and limited thermal and environmental stability constitutes an issue for their potential applications. Here we demonstrate that an oxygen plasma pre-treatment of the ceria (CeO ) surface serves to anchor Pt single atoms, making them active and resistant towards sintering in the CO oxidation reaction.

Operando high-pressure investigation of size-controlled CuZn catalysts for the methanol synthesis reaction.

Although Cu/ZnO-based catalysts have been long used for the hydrogenation of CO to methanol, open questions still remain regarding the role and the dynamic nature of the active sites formed at the metal-oxide interface. Here, we apply high-pressure operando spectroscopy methods to well-defined Cu and CuZn nanoparticles supported on ZnO/AlO, γ-AlO and SiO to correlate their structure, composition and catalytic performance. We obtain similar activity and methanol selectivity for Cu/ZnO/AlO and CuZn/SiO, but the methanol yield decreases with time on stream for the latter sample.

Operando Investigation of Ag-Decorated Cu O Nanocube Catalysts with Enhanced CO Electroreduction toward Liquid Products.

Direct conversion of carbon dioxide into multicarbon liquid fuels by the CO electrochemical reduction reaction (CO RR) can contribute to the decarbonization of the global economy. Here, well-defined Cu O nanocubes (NCs, 35 nm) uniformly covered with Ag nanoparticles (5 nm) were synthesized. When compared to bare Cu O NCs, the catalyst with 5 at % Ag on Cu O NCs displayed a two-fold increase in the Faradaic efficiency for C liquid products (30 % at -1.