There are still great challenges to prepare high‐efficiency Ru‐based catalysts that are superior to Pt/C under acidic conditions, especially under high current conditions. In this work, a series of surfactant‐free noble metal doped Ru/CNT (M‐Ru/CNT, M = Pt, Rh, Pd, Ir, CNT stands for carbon nanotube) are prepared by microwave reduction method in 1 minute with ≈3–3.5 nm in size for the first time. In 0.5 m H2SO4, the overpotential of Pt‐Ru/CNT (Pt: 4.94 at %) is only 12 mV. What's more, it also has much larger electrochemical surface area and intrinsic activity than Pt/C. Pt‐Ru/CNT still has an ultra‐small overpotential under high current density (113 mV at 500 mA cm−2, 155 mV at 1000 mA cm−2). At the same time, it possesses excellent stability regardless of high current or low current after the durability test of 100 h. Theoretical calculation also deeply reveals that Ru is the main adsorption site of H+. The comparison of the electronic structure of a series of noble metals adjusted by Ru shows that Pt has the most excellent Gibbs free energy of the adsorbed hydrogen and promotes the desorption of the product.
At present, it is still a great challenge to synthesize refractory Pt‐based electrocatalysts with excellent active specific surface area, specific activity, and stability by a simple method. Here, a superfast and solvent‐free microwave strategy is reported to synthesize refractory ultrafine (≈3 nm) Pt–lanthanide@Ketjen Black (PtM@KB, M = La, Gd, Tb, Er, Tm, and Yb) alloy with densely packed as efficient hydrogen evolution electrocatalysts in a domestic microwave oven for the first time. The optimized Pt61La39@KB delivers excellent hydrogen evolution reaction (HER) activity with a low overpotential of 38 mV (10 mA cm−2) and a high TOF value of 44.13 s−1 (100 mV) in 0.5 m H2SO4, and performs well in 1.0 m KOH. This method can also be used to grow catalysts on carbon cloth (CC) directly. PtLa@CC shows an overpotential of 99 mV (1000 mA cm−2) in 0.5 m H2SO4 and can maintain activity after 500 h. Theoretical calculations reveal the enhanced stability and activity owing to the higher vacancy formation energy of Pt atoms and the optimized value of ΔGH*. Solvent‐free microwave strategy constitutes a significant insight into the development of refractory electrocatalyst with ultrafine size and highly dense, which can also work well at high current densities.
Defect engineering has become one of the important considerations in today's electrocatalyst design. However, the vacancies in the ordered crystal structure (especially body-centered cubic (bcc) and the effect of ordered vacancies (OVs) on the electronic fabric have not been researched yet. In this work, we report the inaugural time of the generation of OVs in the bcc architecture and discuss the insight of the modulation system of the material and its part in the electrochemical N 2 reduction reaction (NRR). OV-PdCu-2 achieves the highest Faradaic efficiency value of 21.5% at 0.05 V versus RHE. When the potential increases to 0 V versus RHE, the highest ammonia yield is 55.54 μg h −1 mg cat −1 , which is significantly better than the unetched PdCu nanoparticles (12.83 μg h −1 mg cat −1
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