Steering Geometric Reconstruction of Bismuth with Accelerated Dynamics for CO2 Electroreduction.

Bismuth-based materials have emerged as promising catalysts in the electrocatalytic reduction of CO2 to formate. However, the reasons for the reconstruction of Bi-based precursors to form bismuth nanosheets are still puzzling, especially the formation of defective bismuth sites. Herein, we prepare bismuth nanosheets with vacancy-rich defects (V-Bi NS) by rapidly reconstructing Bi19Cl3S27 under negative potential. Theoretical analysis reveals that the introduction of chlorine induces the generation of intrinsic electric field in the precursor, thereby increasing the electron transfer rate and further promoting the metallization of trivalent bismuth. Meanwhile, in situ Raman and ex situ XRD tests verify that Bi19Cl3S27 has a faster reconstruction rate than Bi2S3. The formed V-Bi NS exhibits up to 96% HCOO- Faraday efficiency and 400 mA cm-2 HCOO- partial current densities, and its ECSA normalized formate current density and yield are 2.2 times higher than those of intact bismuth nanosheets (I-Bi NS). Density functional theory (DFT) calculations indicate that bismuth vacancies with electron-rich aggregation reduce the activation energy of CO2 to *CO2- radicals and stabilize the adsorption of the key intermediate *OCHO, thus facilitating the reaction kinetics of formate production.

Integration mesoporous surface and hollow cavity into PtPdRh nano-octahedra for enhanced oxygen reduction electrocatalysis.

Design and synthesis of Pt-based nanocrystals with controlled structural diversity and complexity can potentially bring about multifunctional properties. In this work, we present a facile two-step strategy for the construction of the PtPdRh mesoporous octahedral nanocages (PtPdRh MONCs). This unique nanoarchitectonics rationally integrates multiple advantages (i.e. the octahedral shape, hollow cavity and mesoporous surface) into one catalyst, which facilitates the efficient utilization of noble metal atoms at both of the interior and exterior surfaces. As expected, the resultant PtPdRh MONCs could effectively catalyze the oxygen reduction reaction (ORR) under acidic conditions. The demonstrated ORR activity and catalytic durability are superior to the commercial Pt/C catalyst. The present study would provide a general guidance for architectural and compositional engineering of noble metal nanocrystals with desired functionalities and properties.

Ultralong Ternary PtRuTe Mesoporous Nanotubes Fabricated by Micelle Assembly with a Self-Sacrificial Template.

High surface area and fast mass transport rate are important to enhance the activity and stability of catalysts. In this work, tellurium nanowires and F127 triblock copolymer are used as self-sacrificial and soft templates, respectively, to synthesize PtRuTe mesoporous nanotubes (MNTs). The designed PtRuTe MNTs show uniformly distributed mesopores and an internally hollow structure, which can effectively improve Pt utilization, the catalytic activity and durability, and CO tolerance for the methanol oxidation reaction. Very different from previous 1D metallic catalysts with solid interiors and smooth surfaces, PtRuTe MNTs are unique, with a mesoporous exterior and hollow interior. The facile route presented herein is very feasible for fabricating 1D mesoporous metallic catalysts.

Low-coordinated copper facilitates the *CH2CO affinity at enhanced rectifying interface of Cu/Cu2O for efficient CO2-to-multicarbon alcohols conversion.

The carbon-carbon coupling at the Cu/Cu2O Schottky interface has been widely recognized as a promising approach for electrocatalytic CO2 conversion into value-added alcohols. However, the limited selectivity of C2+ alcohols persists due to the insufficient control over rectifying interface characteristics required for precise bonding of oxyhydrocarbons. Herein, we present an investigation into the manipulation of the coordination environment of Cu sites through an in-situ electrochemical reconstruction strategy, which indicates that the construction of low-coordinated Cu sites at the Cu/Cu2O interface facilitates the enhanced rectifying interfaces, and induces asymmetric electronic perturbation and faster electron exchange, thereby boosting C-C coupling and bonding oxyhydrocarbons towards the nucleophilic reaction process of *H2CCO-CO. Impressively, the low-coordinated Cu sites at the Cu/Cu2O interface exhibit superior faradic efficiency of 64.15 ± 1.92% and energy efficiency of ~39.32% for C2+ alcohols production, while maintaining stability for over 50 h (faradic efficiency >50%, total current density = 200 mA cm-2) in a flow-cell electrolyzer. Theoretical calculations, operando synchrotron radiation Fourier transform infrared spectroscopy, and Raman experiments decipher that the low-coordinated Cu sites at the Cu/Cu2O interface can enhance the coverage of *CO and adsorption of *CH2CO and CH2CHO, facilitating the formation of C2+ alcohols.

Defect-induced triple synergistic modulation in copper for superior electrochemical ammonia production across broad nitrate concentrations.

Nitrate can be electrochemically degraded to produce ammonia while treating sewage while it remains grand challenge to simultaneously realize high Faradaic efficiency and production rate over wide-range concentrations in real wastewater. Herein, we report the defect-rich Cu nanowire array electrode generated by in-situ electrochemical reduction, exhibiting superior performance in the electrochemical nitrate reduction reaction benefitting from the triple synergistic modulation. Notably, the defect-rich Cu nanowire array electrode delivers current density ranging from 50 to 1100 mA cm-2 across wide nitrate concentrations (1-100 mM) with Faradaic efficiency over 90%. Operando Synchrotron radiation Fourier Transform Infrared Spectroscopy and theoretical calculations revealed that the defective Cu sites can simultaneously enhance nitrate adsorption, promote water dissociation and suppress hydrogen evolution. A two-electrode system integrating nitrate reduction reaction in industrial wastewater with glycerol oxidation reaction achieves current density of 550 mA cm-2 at -1.4 V with 99.9% ammonia selectivity and 99.9% nitrate conversion with 100 h stability, demonstrating outstanding practicability.

Phosphorus incorporation accelerates ammonia electrosynthesis over a mesoporous Au film.

In this work, a phosphorus-doped mesoporous Au alloy film is grown on Ni foam (mAuP/NF) via a replacement reaction using diblock copolymers and NaH2PO2 as pore-forming agents and a phosphorus dopant, respectively. Due to the phosphorus doping and well-developed mesoporous structure, the obtained mAuP/NF possesses superior NH3 yield (36.52 µg h-1 mg-1cat.) and faradaic efficiency (20.32%) for ammonia electrosynthesis in neutral conditions, superior to mAu/NF.

Ternary AuPS Alloy Mesoporous Film for Efficient Electroreduction of Nitrogen to Ammonia.

Electrocatalytic nitrogen reduction is a promising strategy to produce ammonia with low energy consumption and an ambient operation condition. Owing to extreme difficulties in nitrogen activation, the design of high-efficiency electrocatalysts is still a great challenge. This work proposes a versatile electrodeposition strategy to construct P, S-codoped Au mesoporous film on carbon paper (mAuPS/CP) using polystyrene-b-poly (ethylene oxide) micelles as surfactants. The continuous mesoporous structure and nonmetal element doping can change the electronic structure and provide sufficient active sites, leading to enhanced N2 adsorption and reduced hydrogen evolution reaction (HER) process. Expectedly, the mAuPS/CP exhibits superior performance [NH3 yield: 58.2 µg h-1 mg-1cat.; Faradaic efficiency (FE): 25.7%] to the counterpart without doping in a neutral electrolyte. This research offers an ingenious method to directly synthesize P, S-codoped mesoporous noble metals for effective ammonia electrosynthesis.

Engineering bunched RhTe nanochains for efficient methanol oxidation electrocatalysis.

Herein, a two-step method is proposed to synthesize bunched RhTe nanochains (RhTe NCs) using Te nanowires and formic acid both as a reductant and a structure-directing agent. The resultant RhTe NCs possess a high electrochemical active surface area of 89.3 m2 gRh-1, and exhibit superior catalytic activity and durability towards the electro-oxidation of methanol in an alkaline medium.

Enhanced Oxygen Reduction and Methanol Oxidation Electrocatalysis over Bifunctional PtPdIr Mesoporous Hollow Nanospheres.

Designing and constructing nano-architectures with abundant reactive atoms exposed on the surface and widely open pore interiors is an effective strategy for highly efficient utilization of Pt-based catalysts. Herein, we report a facile method to synthesize tri-metallic PtPdIr mesoporous hollow nanospheres (PtPdIr MHNSs) by selective chemical removal of sacrificial metallic cores from pre-constructed Pd@PtIr mesoporous nanospheres (Pd@PtIr MNSs). The unique nano-architectures, with mesoporous shells interconnected into the interior hollow cavities and the synergistic electronic effect from tri-metallic PtPdIr composition, enable the as-synthesized PtPdIr MHNSs to be efficient bifunctional electrocatalysts for catalyzing both methanol oxidation reaction (MOR) and oxygen reduction reaction (ORR).