No abstract

Electrochemical production of H2O2 from O2 is a promising alternative to the energy-intensive anthraquinone process that is currently used as an industry standard. Although most research on the oxygen reduction reaction (ORR) has focused on the 4-electron pathway to water relevant to fuel cells, the 2-electron ORR to produce H2O2 is also of significant commercial interest. The first half of this Perspective deals with the progress made in developing noble metal, carbon-based, and single-atom electrocatalysts and highlights the design strategies employed to obtain high selectivity toward H2O2. The second half addresses the challenges of large-scale production and how results obtained using a rotating ring disk electrode (RRDE) can be translated into commercially viable flow cells. This Perspective focuses on the design of catalysts and cells that will enable industrial-scale electrochemical H2O2 production.

Compared to nanostructured platinum (Pt) catalysts, ordered Pt-based intermetallic nanoparticles supported on a carbon substrate exhibit much enhanced catalytic performance, especially in fuel cell electrocatalysis. However, direct synthesis of homogeneous intermetallic alloy nanocatalysts on carbonaceous supports with high loading is still challenging. Herein, we report a novel synthetic strategy to directly produce highly dispersed MPt alloy nanoparticles (M = Fe, Co, or Ni) on various carbon supports with high catalyst loading. Importantly, a unique bimetallic compound, composed of [M­(bpy)3]2+ cation (bpy = 2,2′-bipyridine) and [PtCl6]2– anion, evenly decomposes on carbon surface and forms uniformly sized intermetallic nanoparticles with a nitrogen-doped carbon protection layer. The excellent oxygen reduction reaction (ORR) activity and stability of the representative reduced graphene oxide (rGO)-supported L10-FePt catalyst (37 wt %-FePt/rGO), exhibiting 18.8 times higher specific activity than commercial Pt/C catalyst without degradation over 20 000 cycles, well demonstrate the effectiveness of our synthetic approach toward uniformly alloyed nanoparticles with high homogeneity.

Graphene‐based nanocomposites are characterized by high mechanical strength, excellent electrical conductivity, and outstanding thermal and chemical stability. Additionally, the combination of versatile functionalization chemistry and simplicity of large‐scale synthesis makes graphene ideal for electrode materials for energy storage devices. To improve the electrochemical performance even further, recent research has focused on the preparation of porous graphene structures, either by creating holes in the graphene sheets or by assembling them into a 3D porous framework. Porous graphene and reduced graphene oxide allow for rapid ion diffusion and display high real surface area. In this review paper, the conventional methods for the preparation of porous graphene are summarized and recent progress in porous graphene‐based nanomaterials for electrochemical energy storage devices is discussed.