General Synthesis of Multishell Mixed‐Metal Oxyphosphide Particles with Enhanced Electrocatalytic Activity in the Oxygen Evolution Reaction

We report a general approach for the synthesis of multishell mixed‐metal oxyphosphide particles. Seven‐layer Mn‐Co oxide particles were first prepared by thermal treatment of Mn‐Co coordination polymer precursors. Afterwards, these multishell Mn‐Co oxide particles were further transformed into multishell Mn‐Co oxyphosphide particles through a phosphidation reaction. This approach is very versatile and can be applied to synthesize other multishell mixed‐metal oxyphosphide particles with different compositions. By applying a constant electrochemical potential, these multishell Mn‐Co oxyphosphide particles can be activated to produce Mn‐Co oxide/hydroxide species in their nanoshells and then show greatly enhanced electrocatalytic activity in the oxygen evolution reaction (OER).     

Formation and Functioning of Bimetallic Nanocatalysts: The Power of X‐ray Probes

Bimetallic nanocatalysts are key enablers of current chemical technologies, including car exhaust converters and fuel cells, and play a crucial role in industry to promote a wide range of chemical reactions. However, owing to significant characterization challenges, insights in the dynamic phenomena that shape and change the working state of the catalyst await further refinement. Herein, we discuss the atomic‐scale processes leading to mono‐ and bimetallic nanoparticle formation and highlight the dynamics and kinetics of lifetime changes in bimetallic catalysts with showcase examples for Pt‐based systems. We discuss how in situ and operando X‐ray spectroscopy, scattering, and diffraction can be used as a complementary toolbox to interrogate the working principles of today's and tomorrow's bimetallic nanocatalysts.     

Colloidal Rings by Site‐Selective Growth on Patchy Colloidal Disc Templates

Anisotropic colloidal building blocks are quite attractive as they enable the self‐assembly towards new materials with designated hierarchical structures. Although many advances have been achieved in colloidal synthetic methodology, synthesis of colloidal rings with low polydispersity and on a large scale remains a challenge. To address this issue we introduce a new site‐selective growth strategy, which relies on using patchy particles. For example, by using patchy discs as templates, silica can selectively be grown on only side surfaces, resulting in formation of silica rings. We demonstrate that shape parameters are tunable and find that these silica rings can be used as secondary template to synthesize other types of rings. This method for synthesizing ring‐like colloids provides possibilities for studying their self‐assembly and associated phase transitions, and this patchy particles template strategy paves a new route for fabricating other new colloidal particles.