Bimetallic Nanoparticles Research Articles

Led-induced deposition of Pt and Au NPs on carbon fibers: Developing a novel strategy for facile fabrication of electrocatalysts for enhanced methanol electrooxidation

In addressing the imperative of aligning materials science with sustainable development, our study introduces an innovative method for the simultaneous deposition of Pt and Au nanoparticles onto a carbon support. This research represents the pioneering application of the photodeposition process for synthesizing bimetallic nanoparticles on a carbon matrix. The comprehensive characterization of the resulting nanostructures involves various techniques, including field X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM), atomic force microscopy (AFM), energy-dispersive X-ray analysis (EDX), inductively coupled plasma atomic emission spectroscopy (ICP-OES), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetric techniques. Our findings reveal that the photodeposition method produces a homogeneous AuPt nanostructure, demonstrating superior electrocatalytic activity in methanol oxidation compared to the monometallic carbon fiber_Pt (CF_Pt) catalyst. These results emphasize the effectiveness of our novel approach in fabricating electrocatalysts with exceptional performance in methanol oxidation reactions.

Construction of Metal/Zeolite Hybrid Nanoframe Reactors via in-Situ-Kinetics Transformations.

Metal/zeolite hybrid nanoframes featuring highly accessible compartmental environments, abundant heterogeneous interfaces, and diverse chemical compositions are expected to possess significant potential for heterogeneous catalysis, yet their general synthetic methodology has not yet been established. In this study, we developed a two-step in-situ-kinetics transformation approach to prepare metal/ZSM-5 hybrid nanoframes with exceptionally open nanostructures, tunable metal compositions, and abundant accessible active sites. Initially, the process involved the formation of single-crystalline ZSM-5 nanoframes through an anisotropic etching and recrystallization kinetic transformation process. Subsequently, through an in situ reaction of the Ni2+ ions and the silica species etched from ZSM-5 nanoframes, layered nickel silicate emerged on both the inner and outer surfaces of the zeolite nanoframes. Upon reduction under a hydrogen atmosphere, well-dispersed Ni nanoparticles were produced and immobilized onto the ZSM-5 nanoframes. Strikingly, this strategy can be extended to immobilize a variety of ultrasmall monometallic and bimetallic alloy nanoparticles on zeolite nanoframes. Benefiting from the structural and compositional advantages, the resultant hybrid nanoframes with a high loading of discrete Ni nanoparticles exhibited enhanced performance in the hydrodeoxygenation of stearic acid into liquid fuels. Overall, the methodology shares fresh insights into the rational construction of intricate frame-like metal/zeolite hybrid nanoreactors for many potential catalytic applications.

Biosynthesis of Pt doped Zn bimetallic nanoparticles by using Polygonum glabrum extract for colorimetric, fluorimetric (Ni2+, Hg2+ and Fe2+) ions sensing and photocatalytic degradation of organic dye with electrochemical techniques

In the present study we aimed to explore the biosynthesis and characterization of monometallic platinum nanoparticles (PtNPs), zinc oxide nanoparticles (ZnONPs) are compared to the Pt doped ZnONPs (Pt-ZnONPs) and its sensing, electrochemical, photocatalytic properties. The bimetallic Pt-ZnONPs was synthesized by using Polygonum glabrum leaves extract; it acts as reducing agent and stabilizing agent. The analysis of colorimetric and fluorimertic sensing methods to determine the highly detection of Ni2+, Hg2+ and Fe2+ ions. The optical properties were characterized by UV-visible, FT-IR, XRD, XPS, SEM-EDX and TEM-SAED analysis. The synthesized monometallic PtNPs and ZnONPs are well dispersed spherical and hexagonal particles with sizes ranging from 8 nm to 25 nm. Electrochemical analysis were carried out the synthesized monometallic and bimetallic Pt-ZnONPs oxidation with reduction potentials by using cyclic voltammetry with UV-visible absorption spectroscopy based on band gap energy to calculation of LUMO and HOMO energy levels. The photocatalytic activities with band gap energy 96% for MeB indicated that only Pt doped ZnONPs for bimetallic Pt-ZnONPs nanocatalyst as compared to monometallic PtNPs and ZnONPs for single metal nanocatalyst actions. The highly sensitivity of Ni2+, Hg2+ and Fe2+ ions are combined with synthesized NPs extended to the oxidation-reduction potential for Pt2+ by Zn2+ ions may find sensitivity for trace different metal ions of pollution level with environmental sensing and photocatalytic applications.

Fabricating of Pd and Ni bimetal modified halloysite nanotube composite and its application for photocatalytic degradation of tetracycline

Tetracycline (TC) is extensively employed as a broad-spectrum antibacterial agent, and its byproducts have been identified in a variety of water bodies, posing a significant risk to both aquatic ecosystems and human health. Among the prevalent techniques for treating water contaminants, photodegradation stands out. In this research, we synthesized a novel nanocomposite material, embedding bimetallic nanoparticles onto halloysite nanotubes (HNT) (Pd@Ni/N-HNT), aimed at photocatalytically degrading TC. The Pd@Ni/N-HNT demonstrated the capability to enhance the TC degradation efficiency to 100 % under visible light for a duration of 120 min, effectively doubling the performance of pure H2O2 degradation. The influence of pH levels in aquatic environments on the TC degradation efficiency was explored. Through electron spin resonance (EPR) studies and free radical scavenging tests, it was verified that •O2− and h+ are pivotal in the degradation process. Furthermore, Pd@Ni/N-HNT showcased effective degradation capabilities in both tap and river water, achieving degradation rates exceeding 70 % in 120 min and 95 % in 180 min, respectively. This investigation not only sheds light on the potential of utilizing Pd@Ni/N-HNT as a potent catalyst for the photocatalytic degradation of TC but also offers a comprehensive framework for the future development of nanomaterials aimed at the environmental remediation of organic pollutants. The findings herein provide a pivotal reference and guide for advancing the application of nanotechnology in the purification of water, thereby contributing to the safeguarding of aquatic ecosystems and public health.

Study of Antioxidant, Antimicrobial and Cytotoxic Activities of Ag-Co Bimetallic Nanoparticles Biosynthesized from Red Alga (Amphiroa sp.)

Objectives: To biosynthesize, evaluate, and investigate the green synthesis of silver-cobalt bimetallic nanoparticles using red alga Amphiroa sp. and its interactions with human pathogens in a colloidal condition. Methods: The marine red algal extract of Amphiroa sp. was used to synthesize the bimetallic nanoparticles of Ag and Co. For this 50mL of 10-3 aqueous Ag-Co prepared solutions were combined with 50mL of pure algal extract. It was characterized by UV-Vis, FTIR, XRD, and SEM. It was tested for its antioxidant, antibacterial, and cytotoxic activities. The antibacterial activity of bimetallic nanoparticles was tested on five human pathogens Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Pseudomonas aeruginosa. The MTT assay method was used for cytotoxic activity for MCF-7 Breast cancer cell lines. Findings: The green synthesized Amphiroa sp. bimetallic nanoparticles showed a UV-Vis spectrum absorption peak at 517nm. Analysis of the FTIR spectra verified the functional groups involved in the production of the Ag-Co nanoparticles. The diffraction pattern of silver-cobalt nanoparticles and the X-ray diffraction pattern of silver nanoparticles showed diffraction angles at 2θ values of 32.5°(15), 46.5°(11) which correspond to (111), (200), and (220). The particle size distribution, which ranges from 56 to 250nm, and the shape was revealed by SEM investigation to be cubic to rhomboidal, thus, they were confirmed to be nanoparticles as well as fine particles/particulate matter. Radical scavenging activity by DPPH, ABTS, and ferrous-reducing power assays were used to investigate the antioxidant potential. The antibacterial activity of bimetallic nanoparticles was tested on five human pathogens and with the zone of inhibition of 23, 18, and 20 mm for Pseudomonas aeruginosa, Escherichia coli and Bacillus subtilis, respectively. The cytotoxic effect was observed on MCF-7 cancer cell lines were evaluated by MTT assay. The IC50 value of our Ag-Co bimetallic sample was found to be 70.90µg/ml at 200µg/mL concentrations. Novelty: Biosynthesizing and investigating Ag-Co bimetallic nanoparticles using red alga and its characterization, antioxidant, antimicrobial and cytotoxic activity. Keywords: Amphiroa sp.; Ag-Co Bimetallic nanoparticles (BNPs); antioxidant, antibacterial and cytotoxic activity

New Approach to Synthesizing Cathode PtCo/C Catalysts for Low-Temperature Fuel Cells

The presented study is concerned with a new multi-step method to synthesize PtCo/C materials based on composite CoxOy/C that combines the advantages of different liquid-phase synthesis methods. Based on the results of studying the materials at each stage of synthesis with the TG, XRD, TEM, SEI, TXRF, CV and LSV methods, a detailed overview of the sequential changes in catalyst composition and structure at each stage of the synthesis is presented. The PtCo/C catalyst synthesized with the multi-step method is characterized by a uniform distribution of bimetallic nanoparticles of about 3 nm in size over the surface of the support, which result in its high ESA and ORR activity. The activity study for the synthesized PtCo/C catalyst in an MEA showed better current–voltage characteristics and a higher maximum specific power compared with an MEA based on a commercial Pt/C catalyst. Therefore, the results of the presented study demonstrate high prospects for the developed approach to the multi-step synthesis of PtM/C catalysts, which may enhance the characteristics of proton-exchange membrane fuel cells (PEMFCs).

A review of flame aerosol synthesis technology for the synthesis of nanoparticles and functional energy materials

The outstanding performance of nanomaterials in chemical, magnetic, electrical, catalytic, and mechanical properties has paved the way for the huge market in material fabrication, energy storage, electronics, and many other industries. Traditional synthesis methods are relatively stunted in industrial applicability and scalability due to complex manufacturing processes and long preparation times, hampering the development and commercialisation of nanomaterials. On the other hand, the flame synthesis method emerges as an inexpensive, efficient, and easily scalable method for the commercial production of nanoparticles. The present review aims to highlight the research status and applications of the nanomaterials synthesised by the flame aerosol method. The advancement of flame aerosol synthesis technologies is reviewed, with emphasis on the state-of-the-art flame reactor configuration and design. Critical flame parameters that govern the formation of nanoparticles in the flame are reviewed to provide an understanding of the formation criteria and growth of nanomaterials in the flame environment. The properties and characteristics of carbon-based, platinum group metal, metal oxide, bimetallic nanoparticles, perovskite and high entropy oxide nanomaterials produced by flame synthesis are extensively reviewed. In addition, commercial manufacturing of flame-synthesised materials along with applications of the nanomaterials in the field of thermal or photocatalytic energy storage, fuel cells, and gas sensing are presented.

Silica Confinement for Stable and Magnetic Co-Cu Alloy Nanoparticles in Nitrogen-Doped Carbon for Enhanced Hydrogen Evolution.

Ammonia borane (AB) with 19.6 wt % H2 content is widely considered a safe and efficient medium for H2 storage and release. Co-based nanocatalysts present strong contenders for replacing precious metal-based catalysts in AB hydrolysis due to their high activity and cost-effectiveness. However, precisely adjusting the active centers and surface properties of Co-based nanomaterials to enhance their activity, as well as suppressing the migration and loss of metal atoms to improve their stability, presents many challenges. In this study, mesoporous-silica-confined bimetallic Co-Cu nanoparticles embedded in nitrogen-doped carbon (CoxCu1-x@NC@mSiO2) were synthesized using a facile mSiO2-confined thermal pyrolysis strategy. The obtained product, an optimized Co0.8Cu0.2@NC@mSiO2 catalyst, exhibits enhanced performance with a turnover frequency of 240.9 molH2 ⋅ molmetal ⋅ min-1 for AB hydrolysis at 298 K, surpassing most noble-metal-free catalysts. Moreover, Co0.8Cu0.2@NC@mSiO2 demonstrates magnetic recyclability and extraordinary stability, with a negligible decline of only 0.8 % over 30 cycles of use. This enhanced performance was attributed to the synergistic effect between Co and Cu, as well as silica confinement. This work proposes a promising method for constructing noble-metal-free catalysts for AB hydrolysis.

Synergistic growth of nickel and platinum nanoparticles via exsolution and surface reaction

Bimetallic catalysts combining precious and earth-abundant metals in well designed nanoparticle architectures can enable cost efficient and stable heterogeneous catalysis. Here, we present an interaction-driven in-situ approach to engineer finely dispersed Ni decorated Pt nanoparticles (1-6 nm) on perovskite nanofibres via reduction at high temperatures (600-800 oC). Deposition of Pt (0.5 wt%) enhances the reducibility of the perovskite support and promotes the nucleation of Ni cations via metal-support interaction, thereafter the Ni species react with Pt forming alloy nanoparticles, with the combined processes yielding smaller nanoparticles that either of the contributing processes. Tuneable uniform Pt-Ni nanoparticles are produced on the perovskite surface, yielding reactivity and stability surpassing 1 wt.% Pt/γ-Al2O3 catalysts for CO oxidation. This approach heralds the possibility of in-situ fabrication of supported bimetallic nanoparticles with engineered compositional distributions and performance.

Facile synthesis and surface characterization of platinum and gold bimetallic nanoparticles prepared using hydroalcoholic extract of Bryophyllum Pinnatum: Enhancing efficacy against breast cancer

Primary aim of the proposed study was to explore the green technique for synthesis of bimetallic nanoparticles of platinum and gold metal by employing Bryophyllum pinnatum hydroalcoholic extract (BrPi-P-G-NPs) to explore their potential medicinal properties. Green synthesised bimetallic nanoparticles were characterized by techniques including UV spectroscopy, XRD, FTIR, SEM, TEM, DSC, Particle size and Zeta Potential analysis. Experimental findings confirmed that BrPi-P-G-NPs demonstrate irregular shape, with an average size 34.5 nm. Zeta potential for BrPi and BrPi-P-G-NPs were found to be −8.1 and −24.1 mV, respectively. At a concentration of 75 µg mL−1, the MTT and trypan blue assays of the BrPi-P-G-NPs revealed a cell inhibition rate of 63.54 % and 60.23 %, respectively. In the MCF-7 cell line, the MTT and trypan blue assays recorded IC50 values of 153.54 and 158.04, respectively, for the BrPi-P-G-NPs at the same concentration. Thus, biologically synthesized BrPi-P-G-NPs demonstrated promising anti-cancer properties against human breast cancer cell lines, while showed no signs of toxicity. The enhanced biological activity of BrPi-P-G-NPs can be attributed to their distinctive properties at the nanoscale, as both exhibit lower polydispersity and nanoparticle size, which contribute to increased reactivity and interactions with biological systems. As a result, these BrPi-P-G-NPs nanoparticles synthesized through the biogenic approach using plant extract of Bryophyllum pinnatum have immense potential for a wide range of pharmaceutical applications.

Rational design of NiO nanoflakes and porous GCN nanocomposite for synergic effectiveness on photocatalytic degradation of industry effluents and biological activity

Nanotechnology can alter matter at the nanoscale and generate new materials, gadgets, and technologies with unique features and functions, revolutionizing medicine, energy, electronics, and materials science. This study synthesizes nickel oxide nanoflowers utilizing Strychnos potatorum seed extract as reducing and stabilizing agents in an eco-friendly way. The porous GCN and NiO nanocomposite enhances NiO for multifunctional capabilities. UV–Vis, FTIR, EDX, XRD, and FESEM were used to synthesize and characterize NiO nanoflowers. Further synthesized bimetallic nanoparticles were tested for antibacterial, antioxidant, and catalytic properties. It showed increased antioxidant activity, CV and RB dye degradation, and antibacterial activity against S. aureus and E.Coli. Scavenging was enriched with nanoparticles. The highest degradation rate was 98.2 % for CV dye in 90 min. Nanoparticle concertation at 100 µl/mL inhibited E.Coli the most (18 mm). NiO nanoflowers and NiO-GCN nanocomposite synthesized from Strychnos potatorum seed extract may be a novel antioxidant, antibacterial, and catalytic agent for industrial dye-contaminated wastewater.

Research on the application of WO3 gas sensor based on noble metals modification in cable fire detection

In the monitoring of cable fire, it is of great significance to be able to conduct early fire warning, which requires that sensors have high sensitivity to the cable vapors at low temperatures. In this study, WO3 thick films modified with Au, Pd, and Pt single or bimetallic nanoparticles were fabricated via magnetron sputtering. Gas sensors utilizing these materials exhibited significant response to the low-temperature vapor emitted by YJV22 and YJY23 cables. Among them, Pd/WO3-20 demonstrated a response value of 20 to the vapor of 81[Formula: see text]C YJV22 cables, marking a remarkable 6.3-fold increase compared to pure WO3, and the response time was 13 s. Similarly, Pt/WO3-10 exhibited a response value of 11.11 to the vapor of 104[Formula: see text]C YJY23 cables, representing a 6.9-fold enhancement over pure WO3 with a response time of 12 s. The heating temperature of cables remains below their critical threshold, indicating that it is in the early stages of cable fires, the findings hold significant implications for early warning systems designed to detect cable fires promptly.

Catalytic oxidation of carbon monoxide at low temperature using AuRh/TiO2 bimetallic catalysts: Effect of the synthesis method

AuRh nanoparticles supported on TiO2 P25 were synthesized by two sequential deposition methods: sequential deposition-precipitation with urea (DPU) and impregnation (IMP)-DPU. Segregated nanoparticles (RhcoreAushell ball-cup-type, and Janus-type arrangements) were observed in gold-rhodium bimetallic catalysts, but mainly ball-cup-type and Janus-type nanoparticles were found on catalysts prepared by IMP-DPU. XPS analysis of gold-rhodium bimetallic catalysts, before and after reaction allowed concluding that gold-rhodium interaction on metallic state was an important factor to avoid the oxidation of rhodium during CO oxidation. However, this effect of stabilization of the rhodium metallic phase by gold does not fully explain the promoting effect observed for some bimetallic catalysts on CO oxidation. Some structural aspects such as the atomic arrangement of the bimetallic nanoparticles and the type of active sites, determined by DRIFTS-CO, were also considered. TPR and UV–visible DR spectroscopy characterizations also showed differences in the gold-rhodium interactions.

Morphological effect on Core@shell AuAg nanoparticles for detecting p‐aminothiophenol dimerization by surface‐enhanced Raman spectroscopy

AbstractA series of non‐spherical metallic Au and bimetallic core@shell AuAg nanoparticles (NPs) have been synthesized for SERS improvements. The bimetallic core@shell AuAg NPs were obtained through a controlled overgrowth of an Ag shell onto the surface of two types of non‐spherical Au NPs, used as seeds, Au nanooctaheda (Au NOc) and Au nanotriangles (Au NTs). This Ag overgrowth was able to produce bimetallic core@shell structures such as nanocubes and nanopyramids, respectively. Transmission electron microscopy (TEM) was used to determine the particle size and particle morphology for metallic and bimetallic NPs, and energy‐dispersive X‐ray (EDX) elemental mapping analysis confirmed the core@shell structure of the bimetallic NPs. The plasmonic absorption bands exhibited for each nanosystem were observed by UV–vis spectroscopy. The concentration of Au and Ag in the bimetallic systems was determined by inductively coupled plasma mass spectrometry (ICP‐MS). After synthesis and characterization, p‐aminothiophenol (PATP) was used as a model analyte to investigate the surface‐enhanced Raman spectroscopy (SERS) capabilities of the synthesized metallic and bimetallic nanosystems. In PATP, a dimerization reaction to 4,4′‐dimercaptoazobenzene (DMAB) is produced when it is adsorbed onto the surface of certain noble metals. This SERS analysis was performed at 10−4 M of PATP and by using two different laser wavelengths (532 and 785 nm) in all cases. In this context, we were able to detect the dimerization reaction of PATP to DMAB only for the bimetallic structures and under the 532 nm laser line. Moreover, we have found that the dimerization capacity also depends on the nanoparticle morphology.

A multiparametric study for size and stability of hybrid Fe 2 O 3 -NiO nanoparticles and their statistical transformation

A multiparametric study for size and stability of hybrid Fe ₂ O ₃ -NiO nanoparticles and their statistical transformation

Ag‐Based Bimetallic Nanoparticles for the Catalytic Reduction of Nitrophenol and Organic Dyes: An Overview

AbstractBimetallic nanoparticles with synergistic effects revealed much higher catalytic activity than respective monometallic materials. This review describes bimetallic nanoparticles, especially silver nanoparticles, combined with the other transition elements, such as Ag−Fe, Ag−Co, Ag−Ni, and Ag−Cu, as an enhanced catalytically active material. The coverage is given to the various methods of preparation, in which factors responsible for different structures of bimetallic nanoparticles are thoroughly discussed. Lastly, we explore the use of bimetallic nanoparticles as a catalyst for the degradation of numerous organic pollutants that contribute to water pollution.

Potential efficacy of bimetallic nanoparticles synthesized from extracellular cell-free extract of Penicillium citrinum against Culex quinquefasciatus mosquito larvae, and their photocatalytic activity

The biological synthesis of nanoparticles finds application in the development of novel insecticides and bioremediation agents. In this study, bimetallic nanoparticles were synthesized using copper and zinc salts along with Penicillium citrinum secondary metabolite. The synthesized nanoparticles were analyzed for their insecticidal and photocatalytic efficacy on Culex quinquefasciatus larvae and organic dyes, respectively. The synthesized nanoparticles were characterized by UV spectroscopy, FTIR, XRD, SEM, EDX, and HR-TEM. The results showed fungal metabolite synthesized bimetallic nanoparticles were too toxic for Culex quinquefasciatus larvae, with LC50 and LC90 values of 1016.51 ppm, 4948.12 ppm for 24 h exposure; 184.80 ppm, 718.16 ppm for 48 h exposure, and 59.07 and 338.76 ppm for 72 h exposure, respectively. The Cu–Zn bimetallic nanoparticles showed mild photocatalytic activity on Xylenol orange (36%). This study shows that bimetallic NPs synthesized from Penicillium citrinum are advantageous for mosquito control as well as having photocatalytic dye degradation properties.

Pyrolysis temperature effect on the efficacy of biochar/CuNi composite catalysts for emerging pollutant degradation

Sugarcane pulp bagasse biochar (SCPBB) was produced through pyrolysis from 500 to 900 °C under a nitrogen atmosphere, and their SCPBB/CuNi composites was produced through wetness impregnation with copper and nickel salts followed by pyrolysis. The impact of pyrolysis temperature on SCPBB and SCPBB/CuNi for physic-chemical properties was evaluated. SEM images that spherical bimetallic CuNi nanoparticles were evenly dispersed on the surface of the biochar matrix, and the size of the nanoparticles increased with increasing temperature. In particular, when the pyrolysis temperature is higher than 700 °C, the nanoparticles on the surface exhibit novel structures that are partially embedded or completely enclosed within the porous biochar matrix. FT-IR ATR and Raman spectra proved that SCPBB materials contain abundant surface functional groups and carbonaceous structures, which were preserved by the introduction of metal nanoparticles. TGA demonstrated SCPBB-500 biochar started to lose mass quickly first, followed by SCPBB-700 and finally SCPBB-900, and the weight residues of SCPBB/CuNi increased by 30 %-34 % compared with SCPBB. In addition, the catalytic performance of the synthesized material was explored for the degradation of malachite green (MG) representing dye molecules, Amoxicillin (AMX) representing pharmaceuticals, and methyl-parabens (MP) representing personal care products contaminants. Each SCPBB/CuNi sample showed catalytic degradation performance under Advanted oxidation processes (AOPs), among which the SCPBB/CuNi catalyst obtained by pyrolysis temperature 500 °C performed best. Hence, SCPBB/CuNi demonstrates promising potential as a multifunctional catalyst for diverse environmental pollutants in wastewater treatments.

Deposition of Pd, Pt, and PdPt Nanoparticles on TiO2 Powder Using Supercritical Fluid Reactive Deposition: Application in the Direct Synthesis of H2O2.

In this study, we investigated the catalytic properties of mono- and bimetallic palladium (Pd) and platinum (Pt) nanoparticles deposited via supercritical fluid reactive deposition (SFRD) on titanium dioxide (TiO2) powder. Transmission electron microscopy analyses verified that SFRD experiments performed at 353 K and 15.6 MPa enabled the deposition of uniform mono- and bimetallic nanoparticles smaller than 3 nm on TiO2. Electron-dispersive X-ray spectroscopy demonstrated the formation of alloy-type structures for the bimetallic PdPt nanoparticles. H2O2 is an excellent oxidizing reagent for the production of fine and bulk chemicals. However, until today, the design and preparation of catalysts with high H2O2 selectivity and productivity remain a great challenge. The focus of this study was on answering the questions of (a) whether the catalysts produced are suitable for the direct synthesis of hydrogen peroxide (H2O2) in the liquid phase and (b) how the metal type affects the catalytic properties. It was found that the metal type (Pd or Pt) influenced the catalytic performance strongly; the mean productivity of the mono- and bimetallic catalysts decreased in the following order: Pd > PdPt > Pt. Furthermore, all catalysts prepared by SFRD showed a significantly higher mean productivity compared to the catalyst prepared by incipient wetness impregnation.

Bimetallic PtZn nanoparticles anchored in high-silica SSZ-13 zeolite for efficient propane dehydrogenation

Direct dehydrogenation of propane to propylene (PDH) is a promising route to meet the ever-growing global propylene demand, but the industrial Pt-based catalysts usually suffer from serious deactivation derived from coke deposition and sintering under harsh reaction conditions. In this work, PtZn bimetallic nanoparticles encapsulated into high-silica SSZ-13 zeolites (PtZn@SSZ-13) were synthesized via a facile ligand-protected interzeolite transformation strategy. In a PDH reaction, the synthesized 0.5Pt3Zn@SSZ-13 catalyst exhibits superior catalytic performance with a propane conversion of 23.7% and a propylene selectivity of 96.8%, which is significantly better than that of PtZn supported on high-silica SSZ-13 (0.5Pt3Zn/SSZ-13). Particularly, the high catalytic activity of this catalyst can be kept during three successive oxidation–reduction cycles. Detailed characterizations including HAADF-STEM, XPS, UV–Vis, H2-TPR reveal that the remarkable improvement of PDH performance is attributed to the PtZn synergistic effect as well as the confinement of SSZ-13 zeolites. The DFT calculations and microkinetic simulations also evidenced that the Pt particles anchored on the Zn-doped SSZ-13 zeolite pore framework possessed obviously higher propane dehydrogenation activity, whereas the anti-coking ability of 0.5Pt3Zn@SSZ-13 was also stronger than Pt (111) surface, demonstrating the superior performance of 0.5Pt3Zn@SSZ-13.