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Hydrogen is increasingly viewed as a game‐changer in the clean energy sector. Renewable hydrogen production from water is industrialized by integrating water electrolysis and renewable electricity, but the current cost of water‐born hydrogen remains high though. An ideal scenario would be to produce value‐added chemicals along with hydrogen so the cost can be partially offset. Herein, facilitated bio‐hydrogen extraction and biomass‐derived chemical formation from sugar‐derived 5‐hydroxymethyfurfural (HMF) were achieved via the in‐situ transformation of cobalt‐bound electrocatalysts. The cyanide‐bound cobalt hydroxide exhibited a low voltage at 1.55 V at 10 mA cm−2 for bio‐hydrogen production, compared with an iridium catalyst (1.75 V). The interaction between the biomass intermediate and the cyanide ligand is suggested to be responsible for the improved activity. [ABSTRACT FROM AUTHOR]

Producing stable but active materials is one of the enduring challenges in electrocatalysis and other types of catalysis. Producing branched nanoparticles is one potential solution. Controlling the number of branches and branch size of faceted branched nanoparticles is one of the major synthetic challenges to achieve highly active and stable nanocatalysts. Herein, we use a cubic‐core hexagonal‐branch mechanism to synthesize branched Ru nanoparticles with control over the size and number of branches. This structural control is the key to achieving high exposure of active {10–11} facets and optimum number of Ru branches that enables improved catalytic activity for oxygen evolution reaction while maintaining high stability. [ABSTRACT FROM AUTHOR]

Controlling the formation of nanosized branched nanoparticles with high uniformity is one of the major challenges in synthesizing nanocatalysts with improved activity and stability. Using a cubic‐core hexagonal‐branch mechanism to form highly monodisperse branched nanoparticles, we vary the length of the nickel branches. Lengthening the nickel branches, with their high coverage of active facets, is shown to improve activity for electrocatalytic oxidation of 5‐hydroxymethylfurfural (HMF), as an example for biomass conversion. [ABSTRACT FROM AUTHOR]

The electrocatalysis of the oxygen evolution reaction (OER) at the surface of oxidized metal electrocatalysts is highly dependent on the structure and composition of the surface oxide. Here, Au core‐ Co branched nanoparticles were synthesized using a cubic‐core hexagonal‐branch growth approach in a slow reductive solution synthesis, resulting in highly crystalline metallic hcp Co branches. Electrochemical surface oxidation of the Co branched nanoparticles resulted in formation of Co(OH)2 that enable the formation of a higher number of active sites under OER conditions compared to Co3O4. Differently from polycrystalline spherical Au−Co core‐shell nanoparticles, the oxidized structure on the Co branched nanoparticle surface is retained with electrochemical cycling, resulting in improved OER activity and stability. [ABSTRACT FROM AUTHOR]

Abstract: Achieving stability with highly active Ru nanoparticles for electrocatalysis is a major challenge for the oxygen evolution reaction. As improved stability of Ru catalysts has been shown for bulk surfaces with low‐index facets, there is an opportunity to incorporate these stable facets into Ru nanoparticles. Now, a new solution synthesis is presented in which hexagonal close‐packed structured Ru is grown on Au to form nanoparticles with 3D branches. Exposing low‐index facets on these 3D branches creates stable reaction kinetics to achieve high activity and the highest stability observed for Ru nanoparticle oxygen evolution reaction catalysts. These design principles provide a synthetic strategy to achieve stable and active electrocatalysts. [ABSTRACT FROM AUTHOR]