Organic Macromolecules Research Articles

Anion-mediated interphase construction enabling high-voltage solid-state lithium metal batteries

Enhancing the interphase stability of polymer electrolytes with high-voltage cathodes is crucial for the development of high-energy-density lithium metal batteries (LMBs), especially in wearable devices area. Herein, lithium difluorophosphate (LiDFP) is incorporated into the solid polymer electrolyte of poly(ethylene oxide) (PEO) to enhance the formation of a robust cathode-electrolyte interphase (CEI) in high-voltage LiCoO2 LMBs. Through combining electrochemical measurements, spectroscopic techniques and theoretical calculations, the underlying modification mechanism is revealed. Due to its stronger anionic coordination with both polymer electrolyte chain and proton, and more oxidation-active resultant anion-coordinated polymer compared with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), LiDFP suppresses the formation of the strong acid HTFSI deriving from the deprotonated process of the terminal O-H group thus avoiding the further oxidative attack to the polymeric framework. Furthermore, under the synergetic decomposition of HDFP intermediate, the polymer-derived radical helps to reconstruct a chemo-mechanically stable and Li-conductive CEI layer, which consists of abundant LiF/Li3PO4/LixPOyFz inorganic species distributed in lithiated organic macromolecules. The in-situ constructed CEI effectively passivates catalytic sites on LiCoO2 directly against PEO, resulting in well-maintained layered structure during high-voltage cycling. The proposed interphasial chemistry that regulates CEI formation provides directive knowledge of electrolyte optimization for high-voltage solid-state batteries.

Polymer-Unit Graph: Advancing Interpretability in Graph Neural Network Machine Learning for Organic Polymer Semiconductor Materials.

The graph representation of complex materials plays a crucial role in the field of inorganic and organic materials investigations for developing data-centric materials science, such as those using graph neural networks (GNNs). However, the currently prevalent GNN models are primarily employed for investigating periodic crystals and organic small molecule data, yet they still encounter challenges in terms of interpretability and computational efficiency when applied to polymer monomers and organic macromolecules data. There is still a lack of graph representation of organic polymers and macromolecules specifically tailored for GNN models to explore the structural characteristics. The Polymer-unit Graph, a novel coarse-grained graph representation method introduced in study, is dedicated to expressing and analyzing polymers and macromolecules. By incorporating the Polymer-unit Graph into the GNN models and analyzing the organic semiconductor (OSC) materials database, it becomes possible to uncover intricate structure-property relationships involving branched-chain engineering, fluoridation substitution, and donor-acceptor combination effects on the elementary structure of OSC polymers. Furthermore, the Polymer-unit Graph enables visualizing the relationship between target properties and polymer units while reducing training time by an impressive 98% and minimizing molecular graph representation models. In conclusion, the Polymer-unit Graph successfully integrates the concept of Polymer-unit into the field of GNNs, enabling more accurate analysis and understanding of organic polymers and macromolecules.

Effect of Water Components on Aggregation and Sedimentation of Polystyrene Nanoplastics

The aggregation and sedimentation of micro/nano-plastics significantly affect their migration and distribution in the environment. This study investigated the effects of Na+ and natural organic matter （NOM） on the aggregation and sedimentation of polystyrene nano-plastics （PS-NPs） in the aqueous phase. Six types of water， such as seawater， lake water， and domestic sewage， were used to evaluate the above effects and other potential influencing factors. The results indicated that Na+ could facilitate the sedimentation of PS-NPs when it was less than 80 mmol·L-1， whereas it could promote the aggregation and suspension of PS-NPs when the concentration was greater than 80 mmol·L-1. NOM molecules affected the aggregation and sedimentation of PS-NPs by changing the ζ potential and relative density of particles via forming a multilayer adsorption structure with Na+ on the particle surface. It was observed that NOM greater than 10 mg·L-1 enhanced the dispersion and suspension of PS-NPs， which might have been attributed to the decrease in relative density of the particles as a large amount of NOM was absorbed onto the surface. Compared with synthetic waters， environmental waters enhanced the aggregation of PS-NPs， which may have been related to the amino acid， protein， and other organic macro-molecules in the water.

The synergistic effect of multiple organic macromolecules on the formation of calcium oxalate raphides of Musa spp.

Needle-like calcium oxalate crystals called raphides are unique structures in the plant kingdom. Multiple biomacromolecules work together in the regulatory and transportation pathways to form raphides; however, the mechanism by which this occurs remains unknown. Using banana (Musa spp.), this study combined in vivo methods including confocal microscopy, transmission electron microscopy, and Q Exactive mass spectrometry to identify the main biomolecules, such as vesicles, together with the compositions of lipids and proteins in the crystal chamber, which is the membrane compartment that surrounds each raphide during its formation. Simulations of the vesicle transportation process and the synthesis of elongated calcium oxalate crystals in vitro were then conducted, and the results suggested that the vesicles carrying amorphous calcium oxalate and proteins embedded in raphides are transported along actin filaments. These vesicles subsequently fuse with the crystal chamber, utilizing the proteins embedded in the raphides as a template for the final formation of the structure. Our findings contribute to the fundamental understanding of the regulation of the diverse biomacromolecules that are crucial for raphide formation. Moreover, the implications of these findings extend to other fields such as materials science, and particularly the synthesis of functionalized materials.

Sustainable papaya plant waste and green tea residue composite films integrated with starch and gelatin for active food packaging applications

This study explores the sustainable utilization of wastes from a papaya plant (papaya peels (PP), papaya seeds (PS), leaf-stem (PL)) and dried green tea residues (GTR) for the synthesis of bioplastics. The dried GTR were individually blended with each papaya waste extract and then boiled in water to get three composite papaya plant waste-green tea supernatants. Potato starch and gelatin-based functional films were prepared by integrating each with the composite papaya waste-green tea supernatant liquid. This work introduces a dissolved organic matter (DOM) study to the field of bioplastics, with the goal of identifying the organic components and macromolecules inherent in the PW supernatants. When compared with the films prepared solely from papaya waste (PW) supernatants, PW-GTR composite supernatant films prevent UV light transmission with superior antioxidant and mechanical properties. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction spectroscopy (XRD), and atomic force microscopy (AFM) were utilized to characterize the starch and gelatin PW-GTR films. Owing to the exceptional antioxidant, UV barrier, and remarkable biodegradable properties of the starch/PW/GTR and gelatin/PW/GTR composite films, make them ideal for use in food packaging applications.

Combination of cellulose nanofiber and artificial fusion protein for biocementation

Biomineralization occurring in living organisms is mostly controlled by organic macromolecules such as polysaccharides and proteins. Recently, biomineralization has been attracting much attention as a green and sustainable cementation technique including enzyme-induced carbonate precipitation (EICP), where CaCO3 is formed by hydrolysis of urea by urease in the presence of calcium ions. In this study, we have developed a novel hybrid biocementation method combining CaCO3 and cellulose nanofiber (CNF). In nature, matrix proteins work as a binder at the interface of organic and inorganic materials to form hybrid biomaterials. By mimicking the natural system, we designed an artificial fusion protein to facilitate the deposition of CaCO3 on CNF. Calcite-binding peptide (CaBP) and carbohydrate-binding module (CBM) were introduced in the artificial fusion protein CaBP-CBM to connect CaCO3 and cellulose. The addition of CNF in the EICP system resulted in the formation of a number of small particles of CaCO3 compared to a non-additive system. The addition of the fusion protein CaBP-CBM to CNF led to an increase in the size of CaCO3 particles. Furthermore, the combination of CaBP-CBM and CNF provides higher strength of samples in sand solidification. Therefore, introduction of CNF and the fusion protein would be promising for novel biocementation techniques.

Study on the hydrogen production promotion effect and immobilization mechanisms of copper during the pyrolysis process of waste cotton textiles

Landfilling waste textiles causes a waste of resources. Copper is the main metal in waste textiles, and it is one of the widely used pyrolysis catalysts. This research investigated the role of copper during the pyrolysis process of waste cotton textiles, including the promoting effect on hydrogen generation and its immobilization in biochar. The pyrolysis experiment was conducted on waste pure cotton textiles impregnated with different concentrations of copper nitrate solutions. The experimental results showed that the addition of copper increased the hydrogen concentration by 121%, while the pyrolysis process reduced the copper leaching rate by 57.5%. Hydrogen concentration increased by 123% as the temperature increased, but the high temperature would affect the immobilization of copper. Hydrogen production and copper immobilization could be improved simultaneously around 700 ℃. The gas evolution was monitored by TG-MS and the biochar was characterized by XRD, FTIR, and XPS. The results indicated that the complexation of oxygen−containing functional groups and the generation of metallic copper decreased the leaching of copper, the heterostructure of copper on the surface of biochar catalyzed the secondary cleavage of organic fraction, increasing the production of hydrogen. The mechanism of hydrogen generation involved the decomposition of cellulose, the cleavage of organic macromolecules, and the secondary reaction of small molecule gases.

Protein structures unravel the signatures and patterns of deep time evolution.

The formulation and testing of hypotheses using 'big biology data' often lie at the interface of computational biology and structural biology. The Protein Data Bank (PDB), which was established about 50years ago, catalogs three-dimensional (3D) shapes of organic macromolecules and showcases a structural view of biology. The comparative analysis of the structures of homologs, particularly of proteins, from different species has significantly improved the in-depth analyses of molecular and cell biological questions. In addition, computational tools that were developed to analyze the 'protein universe' are providing the means for efficient resolution of longstanding debates in cell and molecular evolution. In celebrating the golden jubilee of the PDB, much has been written about the transformative impact of PDB on a broad range of fields of scientific inquiry and how structural biology transformed the study of the fundamental processes of life. Yet, the transforming influence of PDB on one field of inquiry of fundamental interest-the reconstruction of the distant biological past-has gone almost unnoticed. Here, I discuss the recent advances to highlight how insights and tools of structural biology are bearing on the data required for the empirical resolution of vigorously debated and apparently contradicting hypotheses in evolutionary biology. Specifically, I show that evolutionary characters defined by protein structure are superior compared to conventional sequence characters for reliable, data-driven resolution of competing hypotheses about the origins of the major clades of life and evolutionary relationship among those clades. Since the better quality data unequivocally support two primary domains of life, it is imperative that the primary classification of life be revised accordingly.

Food nanotechnology: opportunities and challenges.

Food nanotechnology, which applies nanotechnology to food systems ranging from food production to food processing, packaging, and transportation, provides tremendous opportunities for conventional food science and industry innovation and improvement. Although great progress and rapid growth have been achieved in food nanotechnology research owing to the unique food features rendered by nanotechnology, at a fundamental level, food nanotechnology is still in its initial stages and the potential adverse effects of nanomaterials are still a controversial problem that attract public attention. Food-derived nanomaterials, compared to some inorganic nanoparticles and synthetic organic macromolecules, can be digested rapidly and produce similar digestion products to those produced normally, which become the mainstream and trend for food nanotechnology in practical applications, and are expected to be a vital tool for addressing the security problem and easing public concerns. These food-derived materials enable the favourable characteristics of nanostructures to be combined with the safety, biocompatibility, and bioactivity of natural food. Very recently, diverse food-derived nanomaterials have been explored and widely applied in multiple fields. Herein, we thoroughly summarize the fabrication and development of nanomaterials for use in food technology, as well as the recent advances in the improvement of food quality, revolutionizing food supply, and boosting food industries based on foodborne nanomaterials. The current challenges in food nanotechnology are also discussed. We hope this review can provide a detailed reference for experts and food manufacturers and inspire researchers to participate in the development of food nanotechnology for highly efficient food industry growth.

Approaches to Backbone Flexibility in Protein-Protein Docking.

Proteins are the fundamental organic macromolecules in living systems that play a key role in a variety of biological functions including immunological detection, intracellular trafficking, and signal transduction. The docking of proteins has greatly advanced during recent decades and has become a crucial complement to experimental methods. Protein-protein docking is a helpful method for simulating protein complexes whose structures have not yet been solved experimentally. This chapter focuses on major search tactics along with various docking programs used in protein-protein docking algorithms, which include: direct search, exhaustive global search, local shape feature matching, randomized search, and broad category of post-docking approaches. As backbone flexibility predictions and interactions in high-resolution protein-protein docking remain important issues in the overall optimization context, we have put forward several methods and solutions used to handle backbone flexibility. In addition, various docking methods that are utilized for flexible backbone docking, including ATTRACT, FlexDock, FLIPDock, HADDOCK, RosettaDock, FiberDock, etc., along with their scoring functions, algorithms, advantages, and limitations are discussed. Moreover, what progress in search technology is expected, including not only the creation of new search algorithms but also the enhancement of existing ones, has been debated. As conformational flexibility is one of the most crucial factors affecting docking success, more work should be put into evaluating the conformational flexibility upon binding for a particular case in addition to developing new algorithms to replace the rigid body docking and scoring approach.

Optimizing the hydrolysis-acidification stage in municipal wastewater treatment: comparison of immobilized fillers and granular sludge.

The decomposition of organic macromolecules in sewage currently benefits substantially from hydrolysis-acidification. The full use of its qualities can help domestic sewage to biodegrade more quickly, which promotes the subsequent aerobic reactions. This study evaluated the hydrolysis-acidification performance of granular sludge and filler in residential sewage. Both forms were highly effective at producing volatile fatty acids (VFAs) at the beginning of the reaction, but the granular sludge gradually disintegrated over time, particularly at low temperatures. The production of VFAs decreased (68.08 mg/L), and the effluent dissolved organic nitrogen (DON) increased (6.23 mg/L). However, the effluent of fillers remained at a lower level (1.3 mg/L) and produced more VFAs (74.13 mg/L). High-throughput sequencing revealed that the filler included a greater quantity of hydrolytic-acidifying bacteria than the granular sludge, which resulted in higher performance. In this study, the optimal form of utilizing hydrolytic acidifying bacteria was discussed to provide a theoretical basis to improve the full utilization of organic matter in domestic sewage and the removal of as much total nitrogen as possible.

Modification, Structural Characterizations, and Biological Activities of Sulfated Polysaccharides: A Review

AbstractPolysaccharides are another important class of bioactive macromolecules in organisms, in addition to proteins and nucleic acids. Numerous studies have confirmed that polysaccharides have various biological activities, including anti‐inflammatory, antiviral, antioxidant, immunomodulatory, anticancer, and other activities, which have attracted the attention of researchers in the biomedical field. In the past decade, increasing researches have found that sulfation modification can improve many physicochemical properties of polysaccharides, significantly enhance their original biological activities, and even generate new activity. Hence, sulfated polysaccharides have attracted more and more attention. A systematic review of the latest research progress and future development prospects of sulfated polysaccharides is very essential to better understand them. Hence, the study has systematically summarized current knowledge about synthesis, structural characteristics, biological activities, and potential molecular mechanisms of sulfated polysaccharides. This review provides some valuable insights and important guidance for the further study of sulfated polysaccharides.

Macromolecular Crowding and DNA: Bridging the Gap between In Vitro and In Vivo.

The cellular environment is highly crowded, with up to 40% of the volume fraction of the cell occupied by various macromolecules. Most laboratory experiments take place in dilute buffer solutions; by adding various synthetic or organic macromolecules, researchers have begun to bridge the gap between in vitro and in vivo measurements. This is a review of the reported effects of macromolecular crowding on the compaction and extension of DNA, the effect of macromolecular crowding on DNA kinetics, and protein-DNA interactions. Theoretical models related to macromolecular crowding and DNA are briefly reviewed. Gaps in the literature, including the use of biologically relevant crowders, simultaneous use of multi-sized crowders, empirical connections between macromolecular crowding and liquid-liquid phase separation of nucleic materials are discussed.

Biomineralization Grouting for Beach Sand Cemented with MICP

Microbial-induced carbonate precipitation (MICP) is an environmentally friendly approach that relies on the production of calcium carbonate by microorganisms to construct or reinforce coastal structures. In order to address the disadvantages of current coastal countermeasures techniques, MICP is a cost-effective solution that can be used to repair and restore coastal habitats damaged by human activities. The resulting structures formed through MICP are strong and durable, providing long-term protection against erosion and flooding caused by storms or rising sea levels. Biominerals, including calcium carbonate or calcium phosphate, are used to create complex composites with organic molecules by combining the strength of inorganic materials with the versatility and biocompatibility of organic macromolecules. It is of the utmost importance to investigatethe functionality of MICP and scale up its deployment in various fields in order to thoroughly assess the instrument’s application. Coastal erosion has been a severe concern in archipelagic countries. Therefore, this study explored the Miyazaki coast in Japan and the Yogyakarta coastline in Indonesia to minimize coastal erosion using MICP. The bacteria found in Miyazaki (Sporosarcina species) and the Yogyakarta coast (Pseudoalteromonas tetradonis) were used in the experiment. As a result, the sample treated with a gradual injection of the cementation solution achieved about 6 MPa UCS after 21 days of treatment. The objective were investigated the potential biotreatment with original sand materials and to evaluate the long-term durability under saturated conditions. For these purposes, the MICP-treated sand columns were subjected to series of compression tests and wet-drying (WD) durability analysis.

Synergistic mechanism and radicals interaction of the co-pyrolysis of lignite and PE based on ReaxFF-MD and DFT

Co-pyrolysis is a clean and efficient strategy for utilizing coal and plastics to effectively manage plastic waste while improving valuable chemicals. Since coal and plastic belongs to organic macromolecules, the synergistic mechanism is insufficiently clear. In this paper, a kind of lignite and polyethylene (PE) were selected as representatives to study the synergistic effects of the main products during co-pyrolysis. The synergistic mechanism was elucidated at the microscopic level that radicals such as ·H and CnHm· fragments broken from PE broken combined with the tar fragments produced by lignite cleavage, which produces hydrocarbon products. As the temperature increases, the positive synergistic effect of the major liquid and gaseous products increases in a specific temperature range while weakens with a further increase in temperature. Increase of lignite can produce more oxygenated compounds while more hydrocarbons can be obtained by increasing the percentage of PE. The highest synergistic effect occurs at equal ingredients. The energy barriers of the reaction paths in the individual pyrolysis process were higher than those in the co-pyrolysis process, which indicates that the main products, such as aromatic hydrocarbons as well as ethylene are more easily formed in the co-pyrolysis process, thus a manifestation of positive synergistic effect.

Research on the Preparation of Kaolin from Coal Gangue by Flotation Decarburization with Different Collectors

In order to find a better collector for the separation of carbon and kaolin from coal gangue flotation, and to explore the action mechanism of collectors, this paper selected 12 kinds of collectors for systematic comparison, including five non-polar organics with different carbon chain lengths, and polar organic matters with double bonds, triple bonds, benzene, as well as cycloalkyl, ester, carboxyl, and aldehyde groups. The flotation results show that the longer carbon chain (with a carbon atom number of 13~15), the better the flotation effect, the better the effect of the collector with the phenyl group (among the four hydrocarbon groups), and the better the effect of the collector with the ester group (among the three functional groups). In order to explore the flotation mechanism at the microscopic level, the molecular structure of carbon in coal gangue was detected using a solid nuclear magnetic test. Afterwards, the organic macromolecule model of carbon was simulated. Finally, the interaction energy values between carbon and collectors were calculated in accordance with the density functional theory, and the order of the acting force of collectors was obtained, which was consistent with that of the collectors in the macro experiment.

Molecular Engineering of Polymer Enabling Stability of Hybrid Perovskite Solar Cells

How to inhibit the formation of point defects in the preparation process of hybrid perovskite for improving the stability and photovoltaic characteristics has been a hot research issue in recent years. Herein, molecular engineering of polyvinylpyrrolidone (PVP) is focused as a Lewis base for an additive to improve the interface matching of hybrid perovskite solar cells. Based on the molecular binding strategy, the film crystallinity, bond binding, interfacial transport, and water resistance can be effectively regulated, resulting in preferred photovoltaic characteristics. Herein, the highest photoelectric conversion efficiency of perovskite solar cells reaches 19.7% as well as the improved stability of solar cells. Moreover, combined with first‐principles calculation, the mechanism of PVP macromolecules inducing perovskite interfacial binding through molecular engineering is revealed, which provides a feasible route for using organic macromolecules to regulate the crystallinity and photovoltaic characteristics of hybrid perovskite devices.

Deposition behaviors of carboxyl-modified polystyrene nanoplastics with goethite in aquatic environment: Effects of solution chemistry and organic macromolecules

The ubiquitous nanoplastics (NPs) in the environment are emerging contaminants due to their risks to human health and ecosystems. The interaction between NPs and minerals determines the environmental and ecological risks of NPs. In this study, the deposition behaviors of carboxyl modified polystyrene nanoplastics (COOH-PSNPs) with goethite (α-FeOOH) were systematically investigated under various solution chemistry and organic macromolecules (OMs) conditions (i.e., pH, ionic type, humic acid (HA), sodium alginate (SA), and bovine serum albumin (BSA)). The study found that electrostatic interactions dominated the interaction between COOH-PSNPs and goethite. The deposition rates of COOH-PSNPs decreased with an increase in solution pH, due to the enhanced electrostatic repulsion by higher pH. Introducing cations or anions could compress the electrostatic double layers and compete for interaction sites on COOH-PSNPs and goethite, thereby reducing the deposition rates of COOH-PSNPs. The stabilization effects, which were positive with ions valence, followed the orders of NaCl ≈ KCl < CaCl2, NaNO3 ≈ NaCl < Na2SO4 < Na3PO4. Specific adsorption of SO42− or H2PO4− caused a potential reversal of goethite from positive to negative, leading to the electrostatic forces between COOH-PSNPs and goethite changed from attraction to repulsion, and thus significantly decreasing deposition of COOH-PSNPs. Organic macromolecules could markedly inhibit the deposition of COOH-PSNPs with goethite because of enhanced electrostatic repulsion, steric hindrance, and competition of surface binding sites. The ability for inhibiting the deposition of COOH-PSNPs followed the sequence of SA > HA > BSA, which was related to their structure (SA: linear, semi-flexible, HA: globular, semi-rigid, BSA: globular, with protein tertiary structure) and surface charge density (SA > HA > BSA). The results of this study highlight the complexity of the interactions between NPs and minerals under different environments and provide valuable insights in understanding transport mechanisms and environmental fate of nanoplastics in aquatic environments.

Natural Products: A Dependable Source of Therapeutic Alternatives for Inflammatory Bowel Disease through Regulation of Tight Junctions.

Inflammatory bowel disease (IBD), which includes Crohn's disease (CD) and ulcerative colitis (UC), can affect the entire gastrointestinal tract and mucosal layer and lead to intestinal damage and intestinal dysfunction. IBD is an inflammatory disease of the gastrointestinal tract that significantly impacts public health development. Monoclonal antibodies and other synthetic medications are currently used to treat IBD, but they are suspected of producing serious side effects and causing a number of other problems with long-term use. Numerous in vitro and in vivo studies have shown that organic macromolecules from plants and animals have an alleviating effect on IBD-related problems, and many of them are also capable of altering enzymatic function, reducing oxidative stress, and inhibiting the production of cytokines and release of proinflammatory transcriptional factors. Thus, in this paper, the natural products with potential anti-IBD activities and their mechanism of action were reviewed, with a focus on the protective effects of natural products on intestinal barrier integrity and the regulation of tight junction protein expression and remodeling. In conclusion, the insights provided in the present review will be useful for further exploration and development of natural products for the treatment of IBD.

(Invited) Synthesis of Multi-Metallic Nanocatalysts Using a Dendrimer Reactor

Dendrimers are highly branched organic macromolecules with successive layers or “generations” of branch units surrounding a central core. Organic inorganic hybrid versions have also been produced, by trapping metal ions or metal clusters within the voids of the dendrimers. Their unusual, tree-like topology endows these nanometer-sized macromolecules with a gradient in branch density from the interior to the exterior, which can be exploited to direct the transfer of charge and energy from the dendrimer periphery to its core.We show that AuCl3, SnCl2, FeCl3, and so on complexes to the imines groups of a spherical polyphenylazomethine dendrimer in a stepwise fashion according to an electron gradient, with complexation in a more peripheral generation proceeding only after complexation in generations closer to the core has been completed. By attaching an electron-withdrawing group to the dendrimer core, we are able to change the complexation pattern, so that the core imines are complexed last. By further extending this strategy, it should be possible to control the number and location of metal ions incorporated into dendrimer structures, which might and uses as tailored catalysts, building blocks, or fine-controlled clusters for advanced materials. The metal-assembly in a discrete dendrimer molecule can be converted to a size-regulated metal particle with a size smaller than 1 nm as a molecular reactor(Fig.). Due to the well-defined number of metal clusters in the subnanometer region, its property is much different from that of bulk or general metal nanoparticles. The chemistry of nanocatalysts on the sub-nanometer scale is not yet well understood because precise multi-metallic nanoparticles are difficult to synthesize with control over size and composition. The template synthesis of multi-metallic sub-nanocalaysts is achieved using a phenylazomethine dendrimer as a macromolecular template. Figure 1