Metal Nanoparticles Research Articles

Oxygen vacancies promoted hydrogen production from methanol aqueous phase reforming over MgAl−LDHs supported plasmonic Ru nanoparticles catalyst

Catalytic aqueous phase reforming of methanol is a promising process for the sustainable hydrogen production. The search for highly efficient heterogeneous catalyst is a topic of interest. Herein, we report oxygen vacancies enriched MgAl−LDHs supported plasmonic Ru nanoparticles catalyst exhibit excellent photocatalytic performance for efficient hydrogen production at 150 ºC under light irradiation. Characterizations demonstrate abundant oxygen vacancies are introduced into MgAl−LDHs via “memory effect”. The local electron transfer from oxygen vacancies of the MgAl−LDHs to the Ru nanoparticles leading the formation of electron-rich Ru species, which promote the dehydrogenation of methanol under light irradiation. In situ DRIFTS demonstrated a redox mechanism of water-gas shift reaction due to the existence of oxygen vacancies, which resulted a faster hydrogen production rate. This work displays a facile strategy for synthesis of oxygen vacancies rich LDH supported metal nanoparticles catalysts and deep understanding into the pathway and mechanism toward the effective hydrogen production.

Ag@ZIF-8 core-shell nanocomposites as sensitive and stable SERS substrates: Synthesis, optimization, and application in pollutant detection

Although surface-enhanced Raman scattering (SERS) is a powerful spectral analysis technique, its practical application is restricted due to the poor chemical stability of some noble metal nanoparticles. In this work, Ag@ZIF-8 nanocomposites with different ZIF-8 core-shell thicknesses were prepared by coating AgNP surfaces with polyvinylpyrrolidone and adjusting the dosage of zinc nitrate and 2-methylimidazole. Several characterizations have confirmed that the Ag@ZIF-8 nanocomposites was successfully prepared. Based on transmission electron microscopy images and SERS spectral intensity, it was determined that Ag@ZIF-8 nanocomposites with a ZIF-8 shell thickness of 30 nm exhibited optimal SERS performance. As a result of evaluating the uniformity and stability of the composite with 4-ATP as the probe molecule, it showed a relative standard deviation of 6.91 % and a decrease in SERS intensity of 4.5 % after 28 days. Based on the results obtained with Ag@ZIF-8 nanocomposites as the SERS substrate, the detection limits of 4-mercaptopyridine and thiram were as low as 5.87×10−9 M and 6.61×10−8 M, respectively. Furthermore, the finite-difference time-domain simulation reveals an enhancement factor of 2.6×106, which is in good agreement with the experimental value of 1.8×106, confirming its effectiveness as a SERS substrate.

High-efficiency GaAs TFSC based on Ti plasma enhancement

This study proposed a performance enhancement scheme for GaAs thin-film solar cell (TFSC) based on Ti plasma enhancement. It aims to enhance the light absorption ability of the cell by using surface plasmon excitations of metal nanoparticles, and to predict and optimize the performance of the TFSC using the FDTD method. By introducing Ti nanosphere and pyramid structures on the upper and lower surfaces of the cell, the reflection and transmission losses of light are effectively reduced. This increases the interaction between the cell materials and light, and significantly improves the cell's ability to absorb light. It is shown that Ti nanosphere and pyramid structures can localize the electric field near the metal surface, which greatly enhances the absorption of light on the upper and lower surfaces of the cell. In the wavelength range of 380–1200 nm, the absorption of all bands reaches more than 93 %, with an average absorption rate as high as 97.60 %, and is close to perfect absorption in the wavelength range of 700–900 nm. Meanwhile, the photoelectric conversion efficiency (PCE) of the cell reaches 32.72 %, which significantly improves the overall performance of the cell and provides a compelling design solution for the innovation and development of GaAs TFSC technology.

Green synthesized silver nanoparticles and their biomedical applications: a review

Over the last two decades, scientists have become increasingly interested in metallic nanoparticles due to their unique properties, especially in the biomedical field. Green synthesis of metal nanoparticles is a rapidly growing field in nanotechnology due to its viability, reduced toxicity, ecofriendly nature, and ease of preparation. Plants have long been a centre of attraction in the field of medicine because they are a unique source of a variety of bioactive compounds. Silver has been known for its medicinal properties, especially its antibacterial therapeutic effect. Among other metal nanoparticles, silver nanoparticles have taken a special place since it has made a big impact on medical applications. This review aims to provide a comprehensive understanding of the biomedical qualities of medicinal plants, as well as an overview of their impact on the synthesis of green silver nanoparticles. Various biomedical applications of plant-mediated silver nanoparticles will also be highlighted.

Enhancement of oxygen flux through Nb-doped La0.4Sr0.6FeO3-δ ceramic hollow fiber membranes by Fe exsolution

In recent years, numerous studies have focused on the use of mixed ionic-electronic conducting oxides for coupled oxygen separation and catalytic reactions in membrane reactors. A promising strategy for the efficient fabrication of oxygen separation membranes involves modification of the membrane surface via exsolved metal nanoparticles decoration. Here, we present a detailed characterization of the structural and transport properties of a novel membrane material La0.4Sr0.6Fe0.95Nb0.05O3−δ (LSFNb5). The exsolution of Fe nanoparticles was observed after heating of LSFNb5 in a reducing atmosphere (5 % Н2/Ar) and was confirmed by X-ray diffraction analysis, Mössbauer spectroscopy, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. The formation of Fe nanoparticles on the surface of LSFNb5 hollow fiber membrane in the reduction process leads to the enhancement of oxygen fluxes and reduces the apparent activation energy. Kinetic parameters for oxygen transport through LSFNb5 hollow fiber membrane estimated using two different models, are in good agreement with the experimental results. Furthermore, LSFNb5 hollow fiber membrane demonstrates stable performance both before and after surface treatment.

Hybrid lipid-AuNP clusters as highly efficient SERS substrates for biomedical applications

Although Surface Enhanced Raman Scattering (SERS) is widely applied for ultrasensitive diagnostics and imaging, its potential is largely limited by the difficult preparation of SERS tags, typically metallic nanoparticles (NPs) functionalized with Raman-active molecules (RRs), whose production often involves complex synthetic approaches, low colloidal stability and poor reproducibility. Here, we introduce LipoGold Tags, a simple platform where gold NPs (AuNPs) clusters form via self-assembly on lipid vesicle. RRs embedded in the lipid bilayer experience enhanced electromagnetic field, significantly increasing their Raman signals. We modulate RRs and lipid vesicle concentrations to achieve optimal SERS enhancement and we provide robust structural characterization. We further demonstrate the versatility of LipoGold Tags by functionalizing them with biomolecular probes, including antibodies. As proof of concept, we successfully detect intracellular GM1 alterations, distinguishing healthy donors from patients with infantile GM1 gangliosidosis, showcasing LipoGold Tags as advancement in SERS probes production.

Strong Electronic Metal-Support Interactions Enable the Increased Spin State of Co-N4 Active Sites and Performance for Acidic Oxygen Reduction Reaction.

Nonprecious metal catalysts, particularly M-N-C catalysts, are widely recognized as promising contenders for the oxygen reduction reaction (ORR). However, a notable performance gap persists between M-N-C catalysts and Pt-based catalysts under acidic conditions. In this study, hybrid catalysts comprising single Co atoms and ultralow concentrations of Pt3Co intermetallic nanoparticles (NPs) are introduced to enhance ORR performance. Under acidic conditions, these hybrid catalysts demonstrate ORR efficiency with a half-wave potential of 0.895 V, negligible decay even after 80 000 cycles, and a high maximum power density of 1.34 W cm-2 in fuel cells. This performance surpasses those of Co-N-C and Pt/Co-N-C catalysts. Both experimental findings and theoretical computations suggest that the heightened ORR activity stems from an increase in the spin density of Co sites induced by noble metal NPs, facilitating the activation of O-O bonds via side-on overlapping and enabling a transition in the reaction pathway from associative to dissociative processes. This research offers a promising avenue for the systematic design of M-N-C cathodes with an enhanced performance for acidic fuel cells.

Foliar Uptake and Distribution of Metallic Oxide Nanoparticles in Maize (Zea mays L.) Leaf.

The foliar uptake of Fe3O4, Cr2O3, CuO, and ZnO nanoparticles (NPs) by maize (Zea mays L.) was studied in a lab-scale experiment. The significant increase of Fe concentrations in leaves exposed to Fe3O4 was observed in both stomatal closing and stomatal opening treatments, suggesting the presence of a nonstomatal uptake. In parallel treatments with equal doses of Fe3O4 (∼200 nm), Cr2O3 (∼300 nm), CuO (∼30 nm), and ZnO (∼40 nm) (20-200 μg), the retention percentage of Fe in the leaves (21.0-69.0%) was higher than that of Cr, Cu, and Zn (0.5-14.0%). The steric hindrance effect seems more important for NPs of >200 nm, while hydrophobic surface and negative charge promote the foliar uptake of NPs smaller than 200 nm. The accumulation of NPs in the cuticle was observed through dark-field hyperspectral microscopy. Cr2O3, Fe3O4, and CuO NPs were difficult to penetrate the cuticle. In comparison, ZnO further migrated and distributed within the extracellular space of epidermal and mesophyll cells of the exposed leaf, possibly due to its comparatively higher solubility and hydrophilicity. The findings highlight the potential of the nonstomatal uptake, which might be a critical route for metallic oxide NPs to enter the food chain.

Impact of Nickel on Iridium-Ruthenium Structure and Activity for the Oxygen Evolution Reaction under Acidic Conditions.

Proton exchange membrane water electrolysis (PEMWE) is a promising technology to produce hydrogen directly from renewable electricity sources due to its high power density and potential for dynamic operation. Widespread application of PEMWE is, however, currently limited due to high cost and low efficiency, for which high loading of expensive iridium catalyst and high OER overpotential, respectively, are important reasons. In this study, we synthesize highly dispersed IrRu nanoparticles (NPs) supported on antimony-doped tin oxide (ATO) to maximize catalyst utilization. Furthermore, we study the effect of adding various amounts of Ni to the synthesis, both in terms of catalyst structure and OER activity. Through characterization using various X-ray techniques, we determine that the presence of Ni during synthesis yields significant changes in the structure of the IrRu NPs. With no Ni present, metallic IrRu NPs were synthesized with Ir-like structure, while the presence of Ni leads to the formation of IrRu oxide particles with rutile/hollandite structure. There are also clear indications that the presence of Ni yields smaller particles, which can result in better catalyst dispersion. The effect of these differences on OER activity was also studied through rotating disc electrode measurements. The IrRu-supported catalyst synthesized with Ni exhibited OER activity of up to 360 mA mgPGM -1 at 1.5 V vs RHE. This is ∼7 times higher OER activity than the best-performing IrO x benchmark reported in the literature and more than twice the activity of IrRu-supported catalyst synthesized without Ni. Finally, density functional theory (DFT) calculations were performed to further elucidate the origin of the observed activity enhancement, showing no improvement in intrinsic OER activity for hollandite Ir and Ru compared to the rutile structures. We, therefore, hypothesize that the increased activity measured for the IrRu supported catalyst synthesized with Ni present is instead due to increased electrochemical surface area.

Insights into the dynamics of supported Au nanoparticles in the wet environments from first-principles and ReaxFF MD simulations

The interactions between metal and oxide supports have been widely studied, where the size effect of metal nanoparticles (NPs) and the gas environment play critical roles in catalytic performance. We employed density functional theory and ReaxFF reactive force field to investigate the size dependent properties of gold NPs supported on cerium dioxide, such as structural dynamics, adsorption, and electronic properties under wet environments. Distinct dynamic behaviors were observed in wet environments compared to vacuum conditions. In the wet environments, the hydroxide (OH) species preferentially adsorbs on the low coordination sites, such as edge sites, of NPs. This selective absorption induces a reconstruction effect on small NPs. Moderate-sized NPs exhibit significant surface reconstruction due to abundant OH adsorption at interface sites. However, this effect is negligible in larger NPs. A high interfacial population of OH significantly contributes the high catalytic performance of moderate-sized NPs. Moreover, OH adsorption modulates the charge distribution within the NPs, leading to their stabilization through OH-induced charge transfer. These findings provide insights into understanding and optimizing reactions in wet environments, offering a foundation for the development of more effective catalyst.

High density nanofluidic channels by self-sealing for metallic nanoparticles detection

High density nanofluidic channels were successfully fabricated by a novel process, nicknamed as self-sealing process, for the detection of metal nanoparticles dispersed in water using color changes excited by polarized electromagnetic waves. The permittivities of aqueous solutions with various concentrations of metal nanoparticles were calculated by a corrected plasma model. Systematic simulations using finite difference time domain method were carried out in investigating the detection capabilities of the nanofluidic channels for silver, beryllium and copper nanoparticles in water. The pronounced color shifts indicates that the channels possess high sensitivity in the metal nanoparticles detection. The designed nanofluidic channels were then fabricated by a direct flood deposition of a silica film on a pre-replicated hydrogen silsesquioxan (HSQ) grating using electron beam lithography (EBL). The self-sealing technique possesses advantages in simplified processing, encapsulation free and potential of multi-layer nanochannels.

Iron nanoparticles enhance the efficiency of single-atom Fenton-like catalyst by boosting Fe-NX activity

Single-atom catalysts (SACs) have been widely employed for the removal of organic contaminants via advanced oxidation processes (AOPs). The underlying principle involves central metal atoms that interact synergistically with surrounding atoms in specific ensembles to adsorb reactants and facilitate catalytic reactions. However, comprehensive studies exploring the ensemble effect of SACs in combination with metal nanoparticles relatively rare. In this study, we have synthesized a highly active iron single-atom catalyst (Fe@BC), which features both Fe-Nx coordination sites and iron nanoparticles. Fe@BC exhibits remarkable adsorption and degradation capabilities for bisphenol A across a wide pH range from 3.0 to 11.0. Scavenging experiments coupled with electron paramagnetic resonance analysis have revealed that •OH and O2•− are the key reactive oxygen species within the Fe@BC/PAA system, with •OH playing a crucial role in the removal of bisphenol A (BPA). Our comprehensive characterization analysis has validated the simultaneous presence of Fe nanoparticles and Fe-Nx sites, which are crucial for the catalyst's high activity. Furthermore, our experimental data highlight the importance of the synergistic effect between these two components. Density Functional Theory calculations have provided additional insights, showing that the presence of iron nanoparticles significantly boosts the Fe-Nx sites' activity. This enhancement is achieved by increasing adsorption energy, promoting electron transfer to peracetic acid (PAA), and decreasing the energy barrier for the formation of active species. These findings are vital for the strategic refinement of Fe single-atom catalysts for PAA-based advanced oxidation processes.

The Effect of Metallic Nanoparticles Supplementation in Semen Extender on Post-thaw Quality and Fertilizing Ability of Egyptian Buffalo (Bubalus bubalis) Spermatozoa.

Nanomaterials offer several promising prospects in the field of farm animal reproduction, encompassing a broad range of applications such as transgenesis and the precise delivery of substances to sperm cells, antimicrobial, antioxidants properties as well as their potent role in improving cryopreservation methods. The aim of the present study is to explore the effect of supplementing the semen extender with 10µg/mL nano gold (Au-NPs10), 10µg/mL nano silver (Ag-NPs10), 1µg/mL nano selenium (Se-NPs1), and 100µg/mL nano zinc oxide (ZnO-NPs100) on sperm characteristics and kinematics parameters, acrosome integrity, oxidative biomarkers, morphological and apoptosis-like changes of frozen-thawed buffalo bull sperm, and, ultimately, their fertilizing capacity. The results revealed that all aforementioned nano materials significantly improved viability, progressive motility, membrane integrity, acrosome integrity, and kinematic parameters as well as apoptosis-like changes of post-thawed buffalo bull sperm compared to the control (p < 0.05). No discernible effects were observed on sperm ultrastructure morphology measures as a response to the addition of these metallic nanoparticles to the extender. The values of caspase 3 significantly decreased by 64.22, 45.99, 75.59, and 49.39% in Au-NPs10, Ag-NPs10, Se-NPs1, and ZnO-NPs100treated groups, respectively, compared to the control. The addition of 100µg ZnO-NPs to the extender significantly decreased the total count of bacteria, fungi, and yeast compared to the control (p < 0.05). The AuNPs10 and SeNPs1 treated groups showed lower content of malondialdehyde, hydrogen peroxide, and nitric oxide concentrations and higher values of total antioxidant capacity of post-thawed extended semen (p < 0.05). Pregnancy rates increased by 17.5, 20, and 30% in buffalo cows inseminated with sperm treated with ZnO-NPs100, Se-NPs1, and Au-NPs10, respectively, compared to the control group. The present results indicate that the freezing extender supplemented with metallic nanoparticles can be an effective strategy to enhance the cryotolerance and fertility potential of buffalo bull sperm.

Preparation and Characterization of Silver Sulfide Nanoparticle (Ag2S)-Coated Chitosan for the Delivery Of Methotrexate

Background: The preparation of nanoparticles with the efficiency of treatment and diagnosis at the same time has received more and more attention in recent years. Metal nanoparticles are one of the best candidates for this purpose. Methods: Silver sulfide nanoparticle (Ag2S) coated with chitosan was synthesized and then methotrexate was loaded, and then the anticancer property of the synthesized nanoparticles was examined on the cancer cells. Synthesized nanoparticles were characterized using DLS, TEM, FTIR, XRD and UV-Vis techniques. Then, the hemolytic activity of synthesized nanoparticles was evaluated using human red blood cells. Finally, the anticancer effect of synthesized nanoparticles on 4T1 cancer cells was investigated. In this study, Ag2S@CS nanoparticles were synthesized using the mineralization method. Next, methotrexate was loaded in the synthesized nanoparticles. Ag2S@CS-MTX nanoparticles have an average size of approximately 24.02 ± 6.5 nm, with a spherical shape. Results: The synthesized nanoparticles showed a hydrodynamic size of 119.9 nm. The size obtained from DLS analysis is slightly larger than the size obtained from TEM analysis for Ag2S@CS- MTX nanoparticles. Ag2S@CS-MTX nanoparticles have a negative surface charge and tend to repel each other, so they do not show a tendency to aggregate, for this reason it can provide colloidal stability. Conclusion: Examining the toxicity effect of synthesized nanoparticles on 4T1 cell line showed that Ag2S@CS nanoparticles had no significant toxicity effect on 4T1 cell line, but Ag2S@CS- MTX system showed significant toxicity with increasing concentration.

Metal Nanoparticles for Ovarian Cancer Therapy

Background: Ovarian cancer is the most fatal gynecological cancer, with the highest death rate because of its late diagnosis and recurrence. Owing to the inherent drawbacks of conventionally available approaches for ovarian cancer treatment, alternative strategies need to be developed. Recently, nanotechnology-based drug delivery vehicles (polymer, liposome, dendrimers, etc.) have been extensively used in cancer therapy, especially for ovarian cancer. Among various nanoformulations, metal nanoparticle-based approaches are widely studied for ovarian cancer treatment as they offer several advantages, such as high therapeutic output, biocompatibility, non-toxicity, non-inflammatory effects, biodegradability, etc. Objective: This review aimed to emphasize the advancement of metal-based nanoformulations for ovarían cancer therapy along with toxicological aspects. Methods: The information was gathered from many search engines, such as SciFinder, PubMed, and ScienceDirect, to get coverage of suitable research and compile relevant data about metal nanoparticles for ovarian cancer treatment. Results: Investigating metal nanoparticle-based therapies for the treatment of ovarian cancer provides a new direction for future studies. Conclusion: This review highlights the anti-cancer activity of metal nanoformulations for ovarian cancer therapy, recent progress, challenges, and future perspectives in detail, along with the toxicological aspects.

Synergistic Role of the AuAg-Fe3O4 Nanoenzyme for Ultrasensitive Immunoassay of Dengue Virus.

A combination of magnetic and noble metal nanoparticles (NPs) has recently emerged as a potential substance for rapid and sensitive immunosorbent assays. However, to make the assay an alternative method for Enzyme-linked immunosorbent assay, the individual role of each nanoparticle must be explored properly. In this work, an immunoassay has been proposed using two antibody-conjugated iron oxide nanoparticles (Fe3O4NPs) and gold-silver bimetallic nanoparticles (AuAgNPs) to enhance the sensitivity of virus detection by colorimetric TMB/H2O2 signal amplification. A synergistic effect is monitored between Fe3O4NPs and AuAgNPs, which is explored for colorimetric virus detection. The sensor exploits the synergistic effect between the nanoparticles to successfully detect a wide range of dengue virus-like particle (DENV-LP) concentrations ranging from 10 to 100 pg/mL with a detection limit of up to 2.6 fg/mL. In the presence of a target DENV-LP, a sandwich-like structure is formed, which restricts the electron transfer and the associated synergistic effect between the nanoparticles, restricting the TMB oxidation process. Therefore, the synergistic effect is the key to the present work, which accounts for the enhanced rate of the enzymatic reaction on TMB and makes the current method of virus detection more sensitive and reliable compared to the others.

Photocatalytic degradation of rhodamine B using Yb3+-Doped Zn-Mg ferrites synthesized via conventional sol-gel auto-combustion method

The primary goal of our research is to develop a photocatalyst capable of degrading organic molecules in water, achieved through the rare earth Yb3+ doping of Zn-Mg spinel ferrites. A key element of our approach is the use of the conventional sol-gel auto-combustion process, which has proven to be an effective method for synthesizing a high-performing, visible light-driven Zn0.9Mg0.1Fe2-xYbxO4 (x = 0.000, 0.015, 0.030, 0.045, 0.060 and 0.075) nano-ferrites. Many analytical techniques were employed to evaluate the material's physicochemical characteristics, including P-XRD, EDX, FE-SEM, HR-TEM, FTIR, UV–vis, BET, VSM, EIS, and photocatalysis was carried out against the RhB. The impact of Yb3+ ion doping on the material's crystallite size and lattice parameter has been evaluated. It was found that all the samples' crystallite sizes increased between 33 and 41 nm. These magnetite nanoparticles have spherical forms and nanometric particle sizes, as revealed through field scanning electron microscopy (FE-SEM). The FTIR spectra bands at ʋ1 (518–535) and (401–411) ʋ2 subsequently revealed the spinel structure of the synthesized nano-ferrites. The band gap in zinc manganese ferrite increases from 2.51 eV to 2.92 eV after adding ytterbium. The surface area of the Yb3+-doped Zn-Mg ferries ranges from 23.6 m2/g to 27.8 m2/g, making them an excellent choice for data storage. The investigation of magnetic behavior shows the superparamagnetic behavior of all the samples. The produced sample's determined squareness value indicates the magnetostatic interaction between the particles. Because of the low produced coercive field value, these materials can be used in ferrofluids and hyperthermia therapy applications. Furthermore, with a higher RhB removal of 93.80 %, the Yb3+-doped sample photocatalyst successfully separated carriers generated by sunlight. The Yb3+-doped sample (ZMY-5) photocatalyst showed outstanding stability after one cycle of the stability test, obtaining an outstanding RhB elimination of 93.80 %. Zn0.9Mg0.1Yb0.075Fe1.925O4 photocatalyst has substantial promise for large-scale pollutant treatment due to its simple synthesis method, superior magnetic characteristics, exceptional photocatalytic activity for RhB, and excellent stability.

Chitosan Based Zinc and Copper Nanoparticles: Synthesis, Characterization and Antibacterial Activity Investigation

Chitosan biopolymer has been used as a key supporting material for the synthesis of metallic nanoparticles (MNPs) due to its exceptional qualities, which include good capping and stabilizing capabilities, biocompatibility, biodegradability, eco-friendliness, polycationic and non-toxicity. In this study, chitosan-based metal nanoparticles, such as copper nanoparticles (Chi-Cu NPs) and zinc nanoparticles (Chi-Zn NPs) have been synthesized, characterized and checked for their bacteriological properties. The solution casting method has been employed to produce metal nanoparticles based on chitosan. FTIR, TGA, and SEM analysis were employed to characterize the produced nanoparticles. The produced materials are nanomaterials with a size range of 1-100 nm, as demonstrated by the SEM photograph. The generated nanoparticles showed increased antimicrobial activity. Chi-Zn NPs have zones of inhibition of 38, 31, 30 and 39 and Chi-Cu NPs have zones of inhibition of 32, 36, 37 and 32 mm against Pseudomonas aeruginosa, Salmonella bovismorbificans, Salmonella typhi and Escherichia coli bacteria, respectively. Whereas the standard medication kanamycin have zones of inhibition 22, 22, 20 and 20 against those bacteria, respectively. Journal of Engineering Science 15(1), 2024, 45-57

Improving the Selectivity and Stability of Supported Cobalt Catalysts via Static Bi-Doping and Dynamic Trace CO2 Co-feeding during Propane Dehydrogenation.

Simultaneously enhancing selectivity and stability on supported propane dehydrogenation (PDH) catalysts remains a formidable challenge. Here, we report a combined static and dynamic strategy to address these issues synergistically. Firstly, we demonstrate a feasible sol-gel method for preparing atomically-dispersed Bi-decorated metal nanoparticle catalysts (MBi/Al2O3, M= Fe, Co, Ni, and Zn). In PDH testing, the total selectivity of by-products (CH4 and C2H6) significantly decreases to 4% for CoBi catalysts due to the static Bi-doping, compared with 16% for Co-supported catalysts. Secondly, to enhance catalytic stability, we introduce a dynamic trace CO2 co-feeding route. 10CoBi/Al2O3 catalysts exhibit superior durability against coke formation for 330 hours in PDH under a 40% C3H8 atmosphere followed by pure C3H8 conditions at 600 °C while maintaining propylene selectivity at 96%. Notably, introducing trace CO2 leads to a remarkable 6-fold decrease in the deactivation rate constant (kd). Multiple characterizations and density functional theory calculations reveal that charge transfer from atomically-distributed Bi to Co nanoparticles benefits lowering the energy of C3H6 adsorption thereby suppressing by-products. Furthermore, the dynamic co-feeding of trace CO2 facilitates coke removal, suppressing catalyst deactivation. The static Bi-doping and dynamic trace CO2 co-feeding strategy contributes simultaneously to increased selectivity and stability on supported PDH catalysts.

Improving the Selectivity and Stability of Supported Cobalt Catalysts via Static Bi‐Doping and Dynamic Trace CO2 Co‐feeding during Propane Dehydrogenation

Simultaneously enhancing selectivity and stability on supported propane dehydrogenation (PDH) catalysts remains a formidable challenge. Here, we report a combined static and dynamic strategy to address these issues synergistically. Firstly, we demonstrate a feasible sol‐gel method for preparing atomically‐dispersed Bi‐decorated metal nanoparticle catalysts (MBi/Al2O3, M= Fe, Co, Ni, and Zn). In PDH testing, the total selectivity of by‐products (CH4 and C2H6) significantly decreases to 4% for CoBi catalysts due to the static Bi‐doping, compared with 16% for Co‐supported catalysts. Secondly, to enhance catalytic stability, we introduce a dynamic trace CO2 co‐feeding route. 10CoBi/Al2O3 catalysts exhibit superior durability against coke formation for 330 hours in PDH under a 40% C3H8 atmosphere followed by pure C3H8 conditions at 600 °C while maintaining propylene selectivity at 96%. Notably, introducing trace CO2 leads to a remarkable 6‐fold decrease in the deactivation rate constant (kd). Multiple characterizations and density functional theory calculations reveal that charge transfer from atomically‐distributed Bi to Co nanoparticles benefits lowering the energy of C3H6 adsorption thereby suppressing by‐products. Furthermore, the dynamic co‐feeding of trace CO2 facilitates coke removal, suppressing catalyst deactivation. The static Bi‐doping and dynamic trace CO2 co‐feeding strategy contributes simultaneously to increased selectivity and stability on supported PDH catalysts.