Search Results (40)

Seawater electrolysis offers a sustainable route for large-scale, carbon-neutral hydrogen production, but its industrial application is limited by the poor efficiency and durability of current electrocatalysts under high current densities. Herein, we synthesized ultrasmall Pt nanoclusters uniformly anchored on FeCoNi phosphide nanosheet arrays, forming a composite catalyst with outstanding hydrogen evolution reaction (HER) performance in alkaline seawater. The catalyst achieves an ultralow overpotential of 17 mV at −10 mA cm⁻², far surpassing commercial Pt/C, and stably delivers industrial-level current densities up to 2000 A m⁻² for over 2400 h with minimal voltage degradation and low energy consumption (4.16 kWh/Nm³ H₂). X-ray photoelectron spectroscopy revealed strong interfacial electronic interactions between Pt and Fe/Co species, involving electron transfer from Pt that modulates its electronic structure, weakens hydrogen adsorption, and enhances both HER kinetics and Pt dispersion. This work presents a scalable and robust catalyst platform, bridging the gap between laboratory research and industrial seawater electrolysis for green hydrogen production. Full article

The design of efficient hydrogen evolution reaction (HER) catalysts to minimize reaction overpotentials plays a pivotal role in advancing water electrolysis and clean energy solutions. Ru-based catalysts, regarded as potential replacements for Pt-based catalysts, face stability challenges during catalytic process. The precise regulation of metal–support interactions effectively prevents Ru nanoparticle degradation while optimizing interfacial electronic properties, enabling the simultaneous enhancement of catalytic activity and stability. Herein, we design an amorphous/crystalline support and employ in situ replacement to develop a Ru-NiP_x-Ni structure. The crystalline Ni phase with ordered atomic arrangement ensures efficient charge transport, while the amorphous phase with unsaturated dangling bonds provides abundant anchoring sites for Ru nanoclusters. This synergistic structure significantly enhances HER performance, which attains overpotentials of 19 mV at 10 mA cm⁻² and 70 mV at 100 mA cm⁻² in 1 m KOH, with sustained operation exceeding 55 h at 100 mA cm⁻². Electrochemical impedance spectroscopy analysis confirms that the Ru-NiP_x-Ni structure not only has a high density of active centers for HER, but also reduces the charge transfer resistance at the electrode–electrolyte interface, which effectively enhances HER kinetics. This study presents new directions for designing high-efficiency HER catalysts. Full article

Designing and developing highly active, stable, and cost-effective hydrogen evolution reaction (HER) catalysts is crucial in the field of water electrolysis. In this study, we utilize N-doped porous carbon (CoNC) derived from zeolite imidazole metal–organic frameworks (ZIF-67) as support and prepare CoNC-Pt-IM-P via chemical impregnation (CoNC-Pt-IM) and plasma treatment. Systematic analyses reveal that calcined CoNC with pyridinic nitrogen could serve as a robust support to strongly anchor PtCo nanoclusters, while argon plasma treatment could lead to a noticeable aggregation of Co and Pt atoms so as to alter the electronic environment and enhance intrinsic HER catalytic activity. CoNC-Pt-IM-P could exhibit outstanding catalytic activity toward HER, achieving an exceptionally low overpotential of 31 mV at the current density of −10 mA cm⁻² and a Tafel slope of 36 mV dec⁻¹. At an overpotential of 50 mV, its mass activity reaches 4.90 A mg_Pt⁻¹, representing enhancements of 1.5 times compared to CoNC-Pt-IM and 12.3 times compared to commercial 20 wt% Pt/C. Furthermore, it could operate stably for over 110 h at a current density of −10 mA cm⁻², demonstrating its exceptional durability. This work uses plasma treatment to achieve the controllable aggregation of Co and Pt atoms to enhance their catalytic activity, which has the advantage of avoiding excessive particle aggregation compared to the commonly used method of high-temperature calcination. Full article

A comprehensive investigation of hydrogen grabbing towards the formation of hetero-clusters of AlGaN–H, Si–AlGaN–H, Ge–AlGaN–H, Pd–AlGaN–H, and Pt–AlGaN–H was carried out using DFT computations at the CAM–B3LYP–D3/6-311+G (d,p) level of theory. The notable fragile signal intensity close to the parallel edge of the nanocluster sample might be owing to silicon or germanium binding-induced non-spherical distribution of Si–AlGaN or Ge–AlGaN hetero-clusters. Based on TDOS, the excessive growth technique of doping silicon, germanium, palladium, or platinum is a potential approach to designing high-efficiency hybrid semipolar gallium nitride devices in a long-wavelength zone. Therefore, it can be considered that palladium or platinum atoms in the functionalized Pd–AlGaN or Pt–AlGaN might have more impressive sensitivity for accepting the electrons in the process of hydrogen adsorption. The advantages of platinum or palladium over aluminum gallium nitride include its higher electron and hole mobility, allowing platinum or palladium doping devices to operate at higher frequencies than silicon or germanium doping devices. In fact, it can be observed that doped hetero-clusters of Pd–AlGaN or Pt–AlGaN might ameliorate the capability of AlGaN in transistor cells for energy storage. Full article

Pt-based intermetallic compound (IMC) nanoparticles have been considered the most promising catalysts for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFC). Herein, we propose a strategy for producing ordered Pt₃(CoNi) ternary IMC nanoparticles supported on N-doped carbon materials. Particularly, the Co and Ni are originally embedded into ZIF-derived carbon, which diffuse into Pt nanocrystals to form Pt₃(CoNi) nanoparticles. Moreover, a thin layer of carbon develops outside of Pt₃(CoNi) nanoparticles during the cooling process, which contributes to stabilizing the Pt₃(CoNi) on carbon supports. The optimal Pt₃(CoNi) nanoparticle catalyst has achieved significantly enhanced activity and stability, exhibiting a half-wave potential of 0.885 V vs reversible hydrogen electrode (RHE) and losing only 16 mV after 10,000 potential cycles between 0.6 and 1.0 V. Unlike the direct-use commercial carbon (VXC-72) for depositing Pt, we utilized ZIF-derived carbon containing dispersed Co and Ni nanocluster or nanoparticles to prepare ordered Pt₃(CoNi) intermetallic catalysts. Full article

Porous metallic nanomaterials exhibit interesting physical and chemical properties, and are widely used in various fields. Traditional fabrication techniques are limited to metallurgy, sintering, electrodeposition, etc., which limit the control of pore size and distribution, and make it difficult to achieve materials with high surface areas. On the other hand, the chemical preparation of metallic nanoparticles is usually carried out with strong reducing agents or at high temperature, resulting in the formation of dispersed particles which cannot evolve into porous metal. In this study, we reported the simple fabrication of coral-like mesoporous Pd nanomaterial (Pd NC) with a ligament size of 4.1 nm. The fabrication was carried out by simple solvothermal reduction at a mild temperature of 135 °C, without using any templates. The control experiments suggested that tetrabutylammonium bromide (TBAB) played a critical role in the Pd(II) reduction into Pd nanoclusters and their subsequent aggregation to form Pd NC, and another key point for the formation of Pd NC is not to use a strong reducing agent. In alkaline water electrolysis, the Pd NC outperforms the monodisperse Pd NPs and the state-of-the-art Pt (under large potentials) for H₂ evolution reaction, probably due to its mesoporous structure and large surface area. This work reports a simple and novel method for producing porous metallic nanomaterials with a high utilization efficiency of metal atoms, and it is expected to contribute to the practical preparation of porous metallic nanomaterials by solvothermal reductions. Full article

Platinum electrocatalysts on graphene-like supports have recently attracted research interest as components of electrochemical devices based on hydrogen oxidation reactions in acid media due to their improved electrochemical properties, high stability, and conductivity. Within the current work, hydrogen adsorption and the recombination effects of a proton and hydroxonium on a graphene-based electrocatalyst were investigated using density functional theory. The interaction between ions and the platinum surface was simulated for various configurations, including different initial ion distances and angles relative to the surface of the graphene sheet as well as different adsorptions on various Pt atoms (vertices or faces for Pt₁₃ and Pt₁₄ nanoclusters). Then, the geometry optimization was performed. Changes in the density of states during the reactions were studied to analyze the occurrences and alterations of the interactions. A comparative analysis of the obtained adsorption energies of H⁺ and H₃O⁺ with experimental data was conducted. The energy was calculated to be less in absolute value, and intermediates were more stable in adsorption models with the H–Pt–Gr angle of 90° than in models with the angle of 180°. Strong chemical bonding for models with H–Pt distances less than 2 Å was observed from the DOS. Full article

The article reveals for the first time the features of nanoparticle morphology, phase compositions, and their changes when heating FePt and CoPt nanoalloys. Nanoparticles were obtained by co-reduction of precursor solution mixtures with hydrazine hydrate. The features were found by a complex of methods of X-ray diffraction (in situ XRD and X-ray scattering), TEM HR, and cyclic voltammetry. In addition, adsorbometry results were obtained, and the stability of different nanocluster structures was calculated by the molecular dynamics method. There were only FCC solid solutions in the X-ray patterns of the FePt and CoPt nanoalloys. According to XRD, in the case of nanoparticle synthesis with Fe and Co content less than 10 at. %, the composition of solid solutions was close to or practically equal to the composition of the as-synthesized nanoparticles quantified by inductively coupled plasma optical emission spectrometry. For systems synthesis with Fe and Co content greater than the above, the solubility limits (SLs) of Fe and Co in Pt were set 11.4 ± 0.7 at. % and 17.5 ± 0.6 at. %, respectively. Therefore, there were non-registered XRD extra-phases (XRNDPh-1) in the systems when C_Fe,Co ≥ SL. This statement was supported by the results of TEM HR and X-ray scattering: the smallest nanocrystals (1–2 nm) and amorphous particles were found, which qualitatively agreed with the sorbometry and SAXS results. Molecular dynamics calculations of stability for FePt and CoPt alloys claimed the structures of the most stable phase corresponded to phase diagrams (A1 and L12). Specific peculiarities of the morphology and compositions of the solid solutions of nanoalloys were established: structural blockiness (domain) and composition heterogeneity, namely, platinum enrichment of internal (deep) layers and homogenization of the nanoalloy compositions at relatively low temperatures (130–200 °C). The suggested model of the formation of nanoalloys during the synthesis, qualitatively, was compliant with the results of electrochemical deposition of FePt films on the surface of various electrodes. When nanocrystals of solid solutions (C(Fe, Co) < SL) were heated above specific temperatures, there were phase transformations with the formation of two-phase regions, with solid solutions enriched with platinum or iron (non-registered XRD phase XRNDPh-2). The newly formed phase was most likely intermetallic compounds, FePt₃, CoPt₃. As a result of the study, the model was developed, taking into account the nanoscale of the particles: XRDPh (A1, Fe_aPt_1−a) → XRDPh (A1, Fe_m×a−xPt_m−m×a+x) + XRNDPh-2 (Fe_n×a+yPt_n−n×a−y) (here, m + n = 1, m ≤ 1, n ≤ 1). Full article

DNA as an intriguing organic ligand has been widely employed for synthesizing metal nanoclusters and engineering their properties. This review aims to present recent progress on DNA-encoded metal (Ag, Cu, Au, Ag/Pt, Cu/Ag, etc.) nanoclusters (DNA-MNCs), focusing on their applications in the fields of analysis, logic operation, and therapy based on properties including fluorescence, electrochemiluminescence (ECL), and antibacterial and catalytic activity, and summarizes the attractive features of the latest research. The key points are briefly described as follows. (1) Analytical systems have been constructed based on fluorescence regulation, and nuclease-assisted and enzyme-free amplification strategies have been extensively adopted with fluorescent DNA-MNCs for amplified analysis. (2) DNA-MNCs may play more than one role (emitter, quencher, or catalyst) in ECL-based analytical systems. (3) Apart from antibacterial activity, DNA-MNCs also possess apparent catalytic capability, such as enzyme-like activity (i.e., nanozymes), which has been applied in colorimetric systems. (4) Reversibly regulating the catalytic activity of DNA-MNCs has been attained with DNA systems. It is believed that through in-depth investigation of the relationship between atomic structure and property, more novel DNA-MNCs will be explored and applied in the future. Full article

n-Alkane hydroisomerization over bifunctional catalysts is an effective approach for clean fuel production. However, achieving metal–acid synergy and enhancing the catalytic performance by the preparation of bifunctional catalysts with suitable proximity between the metal sites and Brønsted acid sites are still challenging. In this work, a series of Pt/SAPO-11 catalysts with different Pt loading applied in n-heptane hydroisomerization was synthesized. SAPO-11 was synthesized by the Instant Exactness Synthesis (IES) method, which, with unique morphology and pore structure, was chosen as support for the hydroisomerization catalysts; Pt/SAPO-11 was synthesized with the impregnation method, Pt nanoclusters with trace loading were fabricated over the SAPO-11 support, and the as-synthesized catalysts with different Pt loading were labeled as xPt/SAPO-11 (x = 0.1, 0.3, 0.5, 0.8 and 1.0). Various characterizations, including XRD, nitrogen adsorption–desorption, SEM, TEM, NH₃-TPD and XPS, were carried out on catalysts to obtain deep insights into the microstructure and valence states of xPt/SAPO-11. The catalytic performance of xPt/SAPO-11, including catalytic selectivity and conversion, was investigated in the n-heptane hydroisomerization in detail. Pt loading affected the catalytic properties of xPt/SAPO-11 in the hydroisomerization of n-heptane. The selectivity of 0.5Pt/SAPO-11 toward isomers was about 65% with a conversion of 77% at 310 °C, which was obviously higher than other xPt/SAPO-11 catalysts. Full article

In this study, Pt nanoparticles-loaded nitrogen-doped mesoporous carbon nanotube (Pt/NMCT) was successfully synthesized through a polydopamine-mediated “one-pot” co-deposition strategy. The Pt source was introduced during the co-deposition of polydopamine and silica on the surface of SiO₂ nanowire (SiO₂ NW), and Pt atoms were fixed in the skeleton by the chelation of polydopamine. Thus, in the subsequent calcination process in nitrogen atmosphere, the growth and agglomeration of Pt nanoparticles were effectively restricted, achieving the in situ loading of uniformly dispersed, ultra-small (~2 nm) Pt nanoparticles. The method is mild, convenient, and does not require additional surfactants, reducing agents, or stabilizers. At the same time, the use of the dual silica templates (SiO₂ NW and the co-deposited silica nanoclusters) brought about a hierarchical pore structure with a high specific surface area (620 m² g⁻¹) and a large pore volume (1.46 cm³ g⁻¹). The loading process of Pt was studied by analyzing the electron microscope and X-ray photoelectron spectroscopy of the intermediate products. The catalytic performance of Pt/NMCT was investigated in the reduction of 4-nitrophenol. The Pt/NMCT with a hierarchical pore structure had an apparent reaction rate constant of 0.184 min⁻¹, significantly higher than that of the sample, without the removal of the silica templates to generate the hierarchical porosity (0.017 min⁻¹). This work provides an outstanding contribution to the design of supported noble metal catalysts and also highlights the importance of the hierarchical pore structure for catalytic activity. Full article

Noble Metal nanoclusters (NCs) are promising electrochemiluminescence (ECL) emitters due to their amazing optical properties and excellent biocompatibility. They have been widely used in the detection of ions, pollutant molecules, biomolecules, etc. Herein, we found that glutathione-capped AuPt bimetallic NCs (GSH-AuPt NCs) emitted strong anodic ECL signals with triethylamine as co-reactants which had no fluorescence (FL) response. Due to the synergistic effect of bimetallic structures, the ECL signals of AuPt NCs were 6.8 and 94 times higher than those of monometallic Au and Pt NCs, respectively. The electric and optical properties of GSH-AuPt NCs differed from those of Au and Pt NCs completely. An electron-transfer mediated ECL mechanism was proposed. The excited electrons may be neutralized by Pt(II) in GSH-Pt and GSH-AuPt NCs, resulting in the vanished FL. Furthermore, abundant TEA radicals formed on the anode contributed electrons to the highest unoccupied molecular orbital of GSH-Au_2.5Pt NCs and Pt(II), booming intense ECL signals. Because of the ligand effect and ensemble effect, bimetallic AuPt NCs exhibited much stronger ECL than GSH-Au NCs. A sandwich-type immunoassay for alpha fetoprotein (AFP) cancer biomarkers was fabricated with GSH-AuPt NCs as signal tags, which displayed a wide linear range from 0.01 to 1000 ng·mL⁻¹ and a limit of detection (LOD) down to 1.0 pg·mL⁻¹ at 3S/N. Compared to previous ECL AFP immunoassays, this method not only had a wider linear range but also a lower LOD. The recoveries of AFP in human serum were around 108%, providing a wonderful strategy for fast, sensitive, and accurate cancer diagnosis. Full article

Herein, we prepared Pt₂CeO₂ heterojunction nanocluster (HJNS) on multiwalled carbon nanotubes (MWCNTs) in deep eutectic solvents (DESs) which is a special class of ionic liquids. The catalyst was then heat-treated at 400 °C in N₂ (refer to Pt₂CeO₂/CNTs-400). The Pt₂CeO₂/CNTs-400 catalyst showed remarkably improved electrocatalytic performance towards methanol oxidation reaction (MOR) (839.1 mA mg_Pt⁻¹) compared to Pt₂CeO₂/CNTs-500 (620.3 mA mg_Pt⁻¹), Pt₂CeO₂/CNTs-300 (459.2 mA mg_Pt⁻¹), Pt₂CeO₂/CNTs (641.6 mAmg⁻¹) (the catalyst which has not been heat-treated) and commercial Pt/C (229.9 mAmg⁻¹). Additionally, the Pt₂CeO₂/CNTs-400 catalyst also showed better CO poisoning resistance (onset potential: 0.47 V) compared to Pt₂CeO₂/CNTs (0.56 V) and commercial Pt/C (0.58 V). The improved performance of Pt₂CeO₂/CNTs-400 catalyst is attributed to the addition of appropriate CeO₂, which changed the electronic state around the Pt atoms, lowered the d-band of Pt atoms, formed more Ce-O-Pt bonds acting as new active sites, affected the adsorption of toxic intermediates and weakened the dissolution of Pt; on the other hand, with the assistance of thermal treatment at 400 °C, the obtained Pt₂CeO₂ HJNS expose more new active sites at the interface between Pt and CeO₂ to enhance the electrochemical active surface area (ECSA) and the dehydrogenation process of MOR. Thirdly, DES is beneficial to the increase of the effective component Pt(0) in the carbonization process. The study shows a new way to construct high-performance Pt-CeO₂ catalyst for the direct methanol fuel cell (DMFC). Full article

Catalytic systems based on sub-nanoclusters deposited over different supports are promising for very relevant chemical transformations such as many electrocatalytic processes as the ORR. These systems have been demonstrated to be very fluxional, as they are able to change shape and interconvert between each other either alone or in the presence of adsorbates. In addition, an accurate representation of their catalytic activity requires the consideration of ensemble effects and not a single structure alone. In this sense, a reliable theoretical methodology should assure an accurate and extensive exploration of the potential energy surface to include all the relevant structures and with correct relative energies. In this context, we applied DFT in conjunction with global optimization techniques to obtain and analyze the characteristics of the many local minima of Pt₆ sub-nanoclusters over a carbon-based support (graphene)—a system with electrocatalytic relevance. We also analyzed the magnetism and the charge transfer between the clusters and the support and paid special attention to the dependence of dispersion effects on the ensemble characteristics. We found that the ensembles computed with and without dispersion corrections are qualitatively similar, especially for the lowest-in-energy clusters, which we attribute to a (mainly) covalent binding to the surface. However, there are some significant variations in the relative stability of some clusters, which would significantly affect their population in the ensemble composition. Full article

An effective approach for increasing the Noble metal-utilization by decorating the atomic Pt clusters (1 wt.%) on the CoO₂@SnPd₂ nanoparticle (denoted as CSPP) for oxygen reduction reaction (ORR) is demonstrated in this study. For the optimum case when the impregnation temperature for Co-crystal growth is 50 °C (denoted as CSPP-50), the CoPt nanoalloys and Pt-clusters decoration with multiple metal-to-metal oxide interfaces are formed. Such a nanocatalyst (NC) outperforms the commercial Johnson Matthey-Pt/C (J.M.-Pt/C; 20 wt.% Pt) catalyst by 78-folds with an outstanding mass activity (MA) of 4330 mA mg_Pt⁻¹ at 0.85 V vs. RHE in an alkaline medium (0.1 M KOH). The results of physical structure inspections along with electrochemical analysis suggest that such a remarkable ORR performance is dominated by the potential synergism between the surface anchored Pt-clusters, CoPt-nanoalloys, and adjacent SnPd₂ domain, where Pt-clusters offer ideal adsorption energy for O₂ splitting and CoPt-nanoalloys along with SnPd₂ domain boost the subsequent desorption of hydroxide ions (OH⁻). Full article