Driven by the persisting poor understanding of the sluggish kinetics of the hydrogen evolution reaction (HER) on Pt in alkaline media, a direct correlation of the interfacial water structure and activity is still yet to be established. Herein, using Pt and Pt–Ni nanoparticles we first demonstrate a strong dependence of the proton donor structure on the HER activity and pH. The structure of the first layer changes from the proton acceptors to the donors with increasing pH. In the base, the reactivity of the interfacial water varied its structure, and the activation energies of water dissociation increased in the sequence: the dangling O−H bonds < the trihedrally coordinated water < the tetrahedrally coordinated water. Moreover, optimizing the adsorption of H and OH intermediates can re‐orientate the interfacial water molecules with their H atoms pointing towards the electrode surface, thereby enhancing the kinetics of HER. Our results clarified the dynamic role of the water structure at the electrode–electrolyte interface during HER and the design of highly efficient HER catalysts.

The application of Pt alloy catalysts for oxygen reduction reactions (ORRs) in proton-exchange membrane fuel cells is severely impeded by base metal leaching, since the produced metal ions can result in the degradation of a Nafion membrane by replacing H + and inducing a Fenton reaction. Doping Pt with nonmetal elements can significantly mitigate such problems due to the relative harmlessness of the corrosion products of anions. Herein, we developed a phosphorus-doping strategy, which can greatly boost the ORR performance of Pt. Phosphorus was introduced into the near-surface of commercial Pt/C (denoted as P NS -Pt/C) via a surfactant-free method. Highangle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and X-ray photoelectron spectrum (XPS) tests indicate that the introduction of phosphorus induced distortion of the Pt lattice and the downshift of the d-band center. In situ electrochemical Fourier transform infrared (FTIR) spectroscopy with adsorbed CO as a molecule probe further revealed that the introduction of phosphorus can lower the adsorption ability. The ORR mass activity of P NS -Pt/C is as high as 1.00 mA μg Pt −

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Electrochemical nitrogen reduction reaction (NRR) has been considered as a promising alternative to the traditional Haber–Bosch process for the preparation of ammonia (NH3) under ambient conditions. The development of cost-effective electrocatalysts with suppressive activity for hydrogen evolution reaction is critical for improving the efficiency of NRR. Herein, oxygen-containing molybdenum carbides (O-MoC) embedded in nitrogen-doped carbon layers (N-doped carbon) can be easily fabricated by pyrolyzing the chelate of dopamine and molybdate. A rate of NH3 formation of 22.5 μg·h–1·mgcat –1 is obtained at −0.35 V versus reversible hydrogen electrode with a high faradaic efficiency of 25.1% in 0.1 mM HCl + 0.5 M Li2SO4. Notably, the synthesized O-MoC@NC-800 also exhibits high selectivity (no formation of hydrazine) and electrochemical stability. The moderate electron structure induced by the interaction between O-MoC and N-doped carbon shells can effectively weaken the activity of hydrogen evolution reaction and increase the faradaic efficiency of NRR. Additionally, by applying the in situ Fourier transform infrared spectroscopy, an associative reaction pathway is proposed on O-MoC@NC-800. This work provides new insights into the rational design of carbon-encapsulated metal nanoparticles as efficient catalysts for NRR at ambient conditions.

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Tailoring the near‐surface composition of Pt‐based alloy can optimize the surface chemical properties of a nanocatalyst and further improve the sluggish H2 electrooxidation performance in an alkaline electrolyte. However, the construction of alloy nanomaterials with a precise near‐surface composition and smaller particle size still needs to overcome huge obstacles. Herein, ultra‐small PtRu3 binary nanoparticles (<2 nm) evenly distributed on porous carbon (PtRu3/PC), with different near‐surface atomic compositions (Pt‐increased and Ru‐increased), are successfully synthesized. XPS characterizations and electrochemical test confirm the transformation of a near‐surface atomic composition after annealing PtRu3/PC‐300 alloy; when annealing in CO atmosphere, forming the Pt‐increased near‐surface structure (500 °C), while the Ru‐increased near‐surface structure appears in an Ar heat treatment process (700 °C). Furthermore, three PtRu3/PC nanocatalysts all weaken the hydrogen binding strength relative to the Pt/PC. Remarkably, the Ru‐increased nanocatalyst exhibits up to 38.8‐fold and 9.2‐fold HOR improvement in mass activity and exchange current density, compared with the Pt/PC counterpart, respectively. CO‐stripping voltammetry tests demonstrate the anti‐CO poisoning ability of nanocatalysts, in the sequence of Ru‐increased ≥ PtRu3/PC‐300 > Pt‐increased > Pt/PC. From the perspective of engineering a near‐surface structure, this study may open up a new route for the development of high‐efficiency electrocatalysts with a strong electronic effect and oxophilic effect.

Fuel cells that use small organic molecules or hydrogen as anode fuel can power clean electric vehicles. From an experimental perspective, those possible fuel cells electrocatalytic reaction mechanisms are obtained...