Journal of Energy Chemistry最新文献

Advanced OER/HER electrocatalytic alternatives are crucial for the wide adaptation of green hydrogen energy. Herein, Ru/NiMnB spherical cluster pillar (SCP), denoted as Ru/NiMnB, is synthesized using a combination of electro-deposition and hydrothermal reaction. Systematic investigation of Ru doping in the NiMnB matrix revealed significant improvements in electrocatalytic performance. The Ru/NiMnB SCPs demonstrate superior OER/HER activity with low overpotentials of 150 and 103 mV at 50 mA/cm² in 1 M KOH, making them highly competitive with state-of-the-art electrocatalysts. Remarkably, the Ru/NiMnB SCPs exhibit a low 2-E cell voltage of 2.80 V at ultra-high current density of 2,000 mA/cm² in 1 M KOH, outperforming the standard benchmark electrodes of RuO₂ || Pt/C, thereby positioning Ru/NiMnB as one of the best bifunctional electrocatalysts. These SCPs exhibit exceptional high-current characteristics, stability and corrosion resistance, as evidenced by continuous operation at 1,000 mA/cm² high-current density for over 150 h in 6 M KOH at elevated temperatures under harsh industrial conditions. Only a small amount of Ru incorporation significantly enhances the electrocatalytic performances of NiMnB, attributed to increased active sites and improved intrinsic properties such as conductivity, adsorption/desorption capability and reaction rates. Consequently, Ru/NiMnB SCPs present a promising bi-functional electrode concept for efficient green H₂ production.

Electrochemical reduction of NO₂⁻ to NH₃ (NO₂⁻RR) is recognized as an appealing approach for achieving renewable NH₃ synthesis and waste NO₂⁻ removal. Herein, we report isolated Bi alloyed Ru (Bi₁Ru) as an efficient NO₂⁻RR catalyst. Theoretical calculations and in situ electrochemical measurements reveal the creation of Bi₁-Ru dual sites which can remarkably promote NO₂⁻ activation and suppress proton adsorption, while accelerating the NO₂⁻RR protonation energetics to render a high NO₂⁻-to-NH₃ conversion efficiency. Remarkably, Bi₁Ru assembled in a flow cell delivers an NH₃ yield rate of 1901.4 μmol h⁻¹ cm⁻² and an NH₃-Faradaic efficiency of 94.3% at an industrial-level current density of 324.3 mA cm⁻². This study offers new perspectives for designing and constructing p-block single-atom alloys as robust and high-current-density NO₂⁻RR catalysts toward the ammonia electrosynthesis.

The synergy of single atoms (SAs) and nanoparticles (NPs) has demonstrated great potential in promoting the electrocatalytic carbon dioxide reduction reaction (CO₂RR); however, the rationalization of the SAs/NPs proportion remains one challenge for the catalyst design. Herein, a Ni²⁺-loaded porous poly(ionic liquids) (PIL) precursor synthesized through the free radical self-polymerization of the ionic liquid monomer, 1-allyl-3-vinylimidazolium chloride, was pyrolyzed to prepare the Ni, N co-doped carbon materials, in which the proportion of Ni SAs and NPs could be facilely modulated by controlling the annealing temperature. The catalyst Ni-NC-1000 with a moderate proportion of Ni SAs and NPs exhibited high efficiency in the electrocatalytic conversion of CO₂ into CO. Operando Ni K-edge X-ray absorption near-edge structure (XANES) spectra and theoretical calculations were conducted to gain insight into the synergy of Ni SAs and NPs. The charge transfer from Ni NPs to the surrounding carbon layer and then to the Ni SAs resulted in the electron-enriched Ni SAs active sites. In the electroreduction of CO₂, the co-existence of Ni SAs and NPs strengthened the CO₂ activation and the affinity towards the key intermediate of *COOH, lowering the free energy for the potential-determining *CO₂ → *COOH step, and therefore promoted the catalysis efficiency.

Aqueous zinc-ion batteries are highly favored for grid-level energy storage owing to their low cost and high safety, but their practical application is limited by slow ion migration. To address this, a strategy has been developed to create a cation-accelerating electric field on the surface of the cathode to achieve ultrafast Zn²⁺ diffusion kinetics. By employing electrodeposition to coat MoS₂ on the surface of BaV₆O₁₆·3H₂O nanowires, the directional built-in electric field generated at the heterointerface acts as a cation accelerator, continuously accelerating Zn²⁺ diffusion into the active material. The optimized Zn²⁺ diffusion coefficient in CC@BaV₆O₁₆·3H₂O@MoS₂ (7.5 × 10⁻⁸ cm² s⁻¹) surpasses that of most reported V-based cathodes. Simultaneously, MoS₂ serving as a cathodic armor extends the cycling life of the Zn-CC@BaV₆O₁₆·3H₂O@MoS₂ full batteries to over 10000 cycles. This work provides valuable insights into optimizing ion diffusion kinetics for high-performance energy storage devices.