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A simple model to describe rate changes during the reversible electrochemical promotion of supported metal catalysts has been formulated. Polarisation of the interface between the ion-conducting support and the metal modifies the electron extraction potential of the metal as a result of the spillover of ionic oxygen species. By considering a simple reaction mechanism that involves a charged transition state and accounting for the effect of long-range electrostatic interactions, it is possible to express reaction rates as a function of applied overpotential. It is shown that under certain conditions reaction rates are predicted to increase on application of both negative and positive overpotentials, in agreement with some experimental studies (e.g. Refs. [Catal. Today 11 (1992) 303; J. Catal. 159 (1996) 189]), as a result of electron donation and acceptance from both the metal catalyst and the surface O/O2− redox couple. [Copyright &y& Elsevier]

High‐performance nanoparticle platforms can drive catalysis progress to new horizons, delivering environmental and energy targets. Nanoparticle exsolution offers unprecedented opportunities that are limited by current demanding process conditions. Unraveling new exsolution pathways, particularly at low‐temperatures, represents an important milestone that will enable improved sustainable synthetic route, more control of catalysis microstructure as well as new application opportunities. Herein it is demonstrated that plasma direct exsolution at room temperature represents just such a step change in the synthesis. Moreover, the factors that most affect the exsolution process are identified. It is shown that the surface defects produced initiate exsolution under a brief ion bombardment of an argon low‐pressure and low‐temperature plasma. This results in controlled nanoparticles with diameters ≈19–22 nm with very high number densities thus creating a highly active catalytic material for CO oxidation which rivals traditionally created exsolved samples. [ABSTRACT FROM AUTHOR]

The wet air oxidation (WAO) and ultrasound irradiation of sodium dodecylbenzene sulfonate in water was investigated. Heterogeneous catalysts such as a mixed copper-zinc oxide and noble metals, namely platinum, palladium and ruthenium, generally improved the efficiency of the respective uncatalysed process. The performance of sonochemical treatment, although less effective than WAO at high organic concentrations, may improve by a Fenton-like reaction mechanism on the addition of ferrous ions. [ABSTRACT FROM AUTHOR]

Supported bimetallic nanoparticles used for various chemical transformations appear to be more appealing than their monometallic counterparts, because of their unique properties mainly originating from the synergistic effects between the two different metals. Exsolution, a relatively new preparation method for supported nanoparticles, has earned increasing attention for bimetallic systems in the past decade, not only due to the high stability of the resulting nanoparticles but also for the potential to control key particle properties (size, composition, structure, morphology, etc.). In this review, we summarize the trends and advances on exsolution of bimetallic systems and provide prospects for future studies in this field. [ABSTRACT FROM AUTHOR]

Bimetallic exsolution, catalysis, electrochemistry, energy conversion, nanomaterials In the Minireview on page 6666, C. Tang, K. Kousi, D. Neagu, and I. S. Metcalfe review the, approximately, 70 studies published so far, on bimetallic exsolution and identified research trends in this area. Keywords: bimetallic exsolution; catalysis; electrochemistry; energy conversion; nanomaterials EN bimetallic exsolution catalysis electrochemistry energy conversion nanomaterials 1 1 1 04/19/21 20210416 NES 210416 B Exsolution is a relatively new research hotspot b which can be traced back to 2002. [Extracted from the article]

Strong-metal support interaction between Pd and ceria cubes and rods were investigated. Ceria cubes have the ability to access deep layers of ceria oxygen through the (100) surface indicated by STEM-EELS. Polar (100) surface on ceria cubes showed faster oxygen mobility. These oxygens oxidise adsorbate(s) on Pd due to strong electrostatic repulsion. When ceria is used as a support for many redox catalysis involved in green catalysis, it is well-known that the overlying noble metal can gain access to a significant quantity of oxygen atoms with high mobility and fast reduction and oxidation properties under mild conditions. However, it is as yet unclear what the underlying principle and the nature of the ceria surface involved are. By using two tailored morphologies of ceria nanocrystals, namely cubes and rods, it is demonstrated from Scanning Transmission Electron Microscopy with Electron Energy Loss Spectroscopy (STEM-EELS) mapping and Pulse Isotopic Exchange (PIE) that ceria nanocubes terminated with a polar surface (100) can give access to more than the top most layer of surface oxygen atoms. Also, they give higher oxygen mobility than ceria nanorods with a non-polar facet of (110). A new insight for the possible additional role of polar ceria surface plays in the oxygen mobility is obtained from Density Functional Theory (DFT) calculations which suggest that the (100) surface sites that has more than half-filled O on same plane can drive oxygen atoms to oxidise adsorbate(s) on Pd due to the strong electrostatic repulsion. [ABSTRACT FROM AUTHOR]