Research Progress----Shanghai Advanced Research Institute,Chinese Academy of Sciences

Researchers Propose a Novel Ag Electrode for Efficient Electrocatalytic Conversion of CO2

In a study published in Nature Communications, Prof. WEI Wei and Prof. CHEN Wei from Shanghai Advanced Research Institute of the Chinese Academy of Sciences constructed a hierarchical Ag hollow-fiber penetration electrode(HPE), which helped to realize high-efficiency CO2 electroreduction in strongly acidic electrolytes at ampere-level current density.

The electrochemical conversion of CO2 driven by renewable electricity can produce value-added chemicals and feedstocks while mitigating CO2 emissions. Synthesis of valuable chemicals from CO2 electroreduction in acidic media can overcome carbonation, however, how to suppress the hydrogen evolution reaction in such proton-rich environments is very challenging.In a study published in Nature Communications, Prof. WEI Wei and Prof. CHEN Wei from Shanghai Advanced Research Institute of the Chinese Academy of Sciences constructed a hierarchical Ag hollow-fiber penetration electrode(HPE), which helped to realize high-efficiency CO2 electroreduction in strongly acidic electrolytes at ampere-level current density.Previous studies by the research team have indicated that the HPE with a compact structure has shown promising potential for high-rate and efficient CO2 reduction due to enhanced mass transport, thus realizing the generation of CO, formate and C2+ products under ampere-level current density.In order to further explore the efficient working mechanism of HPE in acid system, an Ag2CO3-derived hierarchical micro/nanostructured silver HPE (CD-Ag HPE) was developed to investigate the effects of catalyst microenvironments on CO2 electrolysis performance in an acidic medium (pH =1).Experiments and theoretical studies demonstrated that the the presence of K+ in the acidic electrolyte controlled the onset of the electrocatalytic CO2 reduction reaction (CO2RR), and that a moderate concentration of H+ effectively prevented the carbonation of CO2 and CO2RR active sites due to the precipitation of (bi)carbonate, ensuring sufficient CO2 and CO2RR active sites at the catalyst surface for high-efficiency CO2RR at ampere-level current density.By optimizing the K+ and H+ concentration and CO2 flow rate in a strong acidic electrolyte, a high CO faradaic efficiency of 95% at 4.5 A/cm2 and a 200 h of stability testing at 2 A/cm2 were achieved.In addition, by limiting the availability of input CO2, the CO2 single-pass carbon efficiency for CO2RR reached 87% at a high j of 2 A/cm2, demonstrating remarkable CO2 conversion capability.This study paves the way for high-efficiency CO2 conversion in strong acid by modulating catalyst microenvironments, which has great potential for practical application.Figure. Schematic of Ag hollow fiber penetration electrode for boosting CO2 electroreduction to CO in a strongly acidic electrolyte (Image by SARI)

2024-08-15 more+

Researchers Propose a Novel Cu Electrode for Efficient Electrocatalytic Conversion of CO2

In a study published in Angewandte Chemie, Prof. WEI Wei and Prof. CHEN Wei from Shanghai Advanced Research Institute of the Chinese Academy of Sciences constructed a hierarchical Cu hollow-fiber penetration electrode (HPE), which helped to realize high-efficiency CO2 electroreduction to C2+ products in both neutral and strongly acidic electrolytes at ampere-level.

　　In a study published in Angewandte Chemie, Prof. WEI Wei and Prof. CHEN Wei from Shanghai Advanced Research Institute of the Chinese Academy of Sciences constructed a hierarchical Cu hollow-fiber penetration electrode (HPE), which helped to realize high-efficiency CO2 electroreduction to C2+ products in both neutral and strongly acidic electrolytes at ampere-level.
　　The electrochemical conversion of CO2 into carbon-based fuels and valuable feedstocks by renewable electricity is an attractive strategy for both the mitigation of the greenhouse gas effect and the consumption of renewable energy. However, it remains a challenge to possess efficient conversion of CO2 to C2+ products in acidic system due to hydrogen evolution.
　　Previous studies by the research team have shown that the Cu hollow fiber permeation electrode can greatly improve the CO2 coverage because of its unique porous structure, thus realizing the generation of C2+ products under ampere-level current under acidic conditions.
　　To further improve the selectivity of C2+ products at ampere-level current density, researchers constructed in situ lattice strained nanosheets of copper on the surface of Cu permeation electrode by wet chemical/ electrochemical reduction method.
　　High concentration of K+ could concurrently suppress hydrogen evolution reaction and facilitate C–C coupling. The synergistic effect of lattice strain effect and gas permeability effect enables the Cu permeable electrode to efficiently and stably convert CO2 into C2+ products under both neutral and acidic conditions (Current density > 3.5 A cm-2, C2+ products faraday efficiency >80%).
　　Experimental measurements, in-situ spectroscopy studies, and density functional theory simulations revealed that tensile-strained Cu HPE boosted the asymmetric C–C coupling to steer the selectivity and activity of C2+ products.This study provides the novel approach to construct efficient catalysts with tensile strain for electrochemical carbon dioxide reduction reaction to C2+ and C2+ alcohols. Schematic diagram and electrocatalytic performance of electroreduction of CO2 to multicarbon products over Cu penetration electrode in acidic system (Image by SARI)
　　Contact：CHEN WeiShanghai Advanced Research InstituteEmail:chenw@sari.ac.cn

2024-07-18 more+

Researchers Develop ZrO₂–Ru Interface to Boost Fischer-Tropsch Synthesis to Olefins

A research team led by Profs. ZHONG Liangshu, LIN Tiejun and LI Shenggang from the Shanghai Advanced Research Institute of the Chinese Academy of Sciences have constructed a ZrO2-Ru interface structure, which greatly enhanced the FTO performance. The work shows that the ZrO2-Ru interface could be engineered by loading the ZrO2 promoter onto silica-supported Ru nanoparticles (ZrRu/SiO2), achieving 7.6 times higher intrinsic activity and ~45% reduction in the apparent activation energy compared with the unpromoted Ru/SiO2 catalyst.

Considering the high cost of noble metal Ru, the creation of highly active interfacial sites at low Ru loading is identified as a key scientific challenge for Ru-based Fischer-Tropsch synthesis to olefin (FTO).A research team led by Profs. ZHONG Liangshu, LIN Tiejun and LI Shenggang from the Shanghai Advanced Research Institute of the Chinese Academy of Sciences have constructed a ZrO2-Ru interface structure, which greatly enhanced the FTO performance.The work shows that the ZrO2-Ru interface could be engineered by loading the ZrO2 promoter onto silica-supported Ru nanoparticles (ZrRu/SiO2), achieving 7.6 times higher intrinsic activity and ~45% reduction in the apparent activation energy compared with the unpromoted Ru/SiO2 catalyst.Their pioneering work, published in Nat. Commun., provides the scientific basis for designing highly active, highly selective, highly stable, and economically feasible Ru-based FTO industrial catalysts.Various characterizations reveal that the highly dispersed ZrO2 promoter strongly binds the Ru nanoparticles to form the Zr-O-Ru interfacial structure, which strengthens the hydrogen spillover effect and serves as a reservoir for active H species by forming Zr-OH* species.Density functional theory calculations were further employed to investigate the promotional effect of ZrO2 to the Ru catalyst for CO activation and dissociation. The simulations suggest the formation of Zr-OH species at the Zr-O-Ru interface, which results from the barrierless dissociation of H2 molecules and the subsequent migration of the H* adsorbates to the Zr-O-Ru interface with a modest energy barrier.Furthermore, the calculations also reveal a change of the H-assisted CO dissociation route from the formyl (HCO*) pathway to the hydroxy-methylidyne (COH*) pathway, which significantly reduces the energy barrier of CO dissociation and greatly enhances CO reactivity.Thus, the much higher FTO activity of the ZrO2-promoted Ru catalyst over the unpromoted Ru catalyst can be attributed to the presence of Zr-OH species at the Zr-O-Ru interface, indicating the importance of the chemical state of the active species on its reactivity.This work deepens our understanding of the metal-promoter interaction, and shed light on the design of efficient industrial Fisher-Tropsch synthesis catalysts.
　　 Fig.1 Diagram showing CO dissociation mechanism and catalytic performance over Ru and ZrO2/Ru interfacial sites (Image by SARI)

2024-07-15 more+

Researchers Find Novel Rhombic Ice Phase Formation from Aqueous Salt Solutions

A research team at Shanghai Advanced Research Institute (SARI) of the Chinese Academy of Sciences reported a systematic study of the two-dimensional rhombic ice formation process from various aqueous solutions at ambient temperature under strong compressed confinement of graphene.The research results were published as a Letter in Physical Review E.

　　Two dimensional ice has been confirmed to play a ubiquitous role in many physical processes like surface wetting, antifreezing, adhesion, friction, etc. Though many work has been done on investigating two-dimensional ice on various solid surfaces, the geometry and thermodynamics of ice formation in salt solutions at the solid-liquid interface are still less understood, due to the complex interactions between salt ions, water molecules, and solid surfaces.
　　Motivated by such a challenge, a research team led by Prof. CHEN Jige at Shanghai Advanced Research Institute (SARI) of the Chinese Academy of Sciences reported a systematic study of the two-dimensional rhombic ice formation process from various aqueous solutions at ambient temperature under strong compressed confinement of graphene.
　　The research results were published as a Letter in Physical Review E.
　　The classical molecular dynamics simulation (MD) shows that two rhombic ice phases grow from the aqueous salt solutions by applying continuous external compression in the confined graphene layers.
　　The rhombic ice phases possess identical geometry and thermodynamic properties such as the configuration entropy, tetrahedral order parameter, and hydrogen bond number, but with different projections of the oxygen atoms against solid surface symmetry.
　　The density functional theory (DFT) calculation reveals that the rhombic ice phase relates to the stable and metastable arrangements of water molecules. The rhombic ice formation is a general phenomenon in different aqueous solutions like NaCl, LiCl, KCl, CaCl2 , MgCl2 , and AlCl3 solutions, etc.
　　The result indicates salt ions and the hydration shell of water molecules around salt ions would heavily contribute to the ice formation process. It is thus particular important in practical applications since salt ions are commonly present in our liquid environment.
　　The result further enlightens our understanding of the ordered geometry of water molecules and the complex hydrated structures on the solid surface.
　　Contact: CHEN Jige
　　Shanghai Advanced Research Institute
　　Email:chenjg@sari.ac.cn

2024-07-05 more+

Researchers Developed Novel Molecular Electrocatalysts for Hydrogen Peroxide Electrosynthesis

A research team at Shanghai Advanced Research Institute of the Chinese Academy of Sciences proposed a strategy to promote H2O2 selectivity by designing a cobalt porphyrin supported on reduced graphene oxide molecular catalyst (CoTPP@RGO), which enabled the stable electrosynthesis of H2O2 at industrial-scale current in PEM electrolyzer. The results were published in Angewandte Chemie International Edition in June, 2024.

Molecular electrocatalysts are regarded as a promising alternative for the electrolysis of hydrogen peroxide (H2O2) through two-electron oxygen reduction reaction (2e-ORR). And oxygen-functionalized groups (OFGs) on the carbon supports are proven to have a great influence on the molecular center.
　　However, such catalysts are always limited by their poor electrocatalytic activity and durability in acidic solution and little work has been done to investigate the interaction mechanism when the specific OFG interacts with the active center.
　　Recently, a research team led by Prof. YANG Hui at Shanghai Advanced Research Institute (SARI) of the Chinese Academy of Sciences proposed a strategy to promote H2O2 selectivity by designing a cobalt porphyrin supported on reduced graphene oxide molecular catalyst (CoTPP@RGO), which enabled the stable electrosynthesis of H2O2 at industrial-scale current in PEM electrolyzer.
　　The results were published in Angewandte Chemie International Edition in June, 2024.
　　Scientists tailored the variation of the single oxygen functional group (OFG) on the reduced graphene oxide (RGO) carrier at the specific temperature and prepared several CoTPP@RGO-T catalysts.
　　Advanced characterization techniques combined with density functional theory calculations revealed the regulation effects of different oxygen functional groups on the electronic structure of active center and unraveled the enhancement mechanism of 2e-ORR activity on the developed CoTPP@RGO catalyst.
　　It was found that PEM electrolyzer with the CoTPP@RGO-160 catalyst could continuously produce pure H2O2 aqueous solution with a high concentration of up to ca. 7 wt% at 400 mA cm-2 over 200 h with a low cell voltage of ~2.1 V, demonstrating the breakthrough of exceptional stability.
　　The findings provide a new strategy for the rational design of the active centers for molecular catalyst, highlighting the enormous potential of supported molecular catalysts for the electrosynthesis of H2O2 in acidic environment as well as its application in industrial-scale H2O2 electrosynthesis.
　　Interaction mechanism investigation and PEM performance evaluation(Image by SARI)
　　Contact: YANG Hui
　　Shanghai Advanced Research Institute
　　Email: yangh@sari.ac.cn
　　

2024-06-20 more+

Scientists Propose a Novel Artificial Intelligence Approach for Lipid Nanoparticles Screening in mRNA Delivery

A joint research team proposed a deep learning model named TransLNP, which based on self-attention mechanisms that maps the three-dimensional microstructure and biochemical properties of mRNA-LNPs to enable high-precision automated screening of LNPs.The research findings were published in Briefings in Bioinformatics.

　　Messenger RNA (mRNA) vaccines targeting pan-cancer therapy hold significant academic and economic value in drug research. A key challenge in mRNA design is the construction of delivery systems called lipid nanoparticles (LNPs), which serve as carriers to deliver mRNA therapies or vaccines to target cells. The preparation and screening of LNPs components involve long cycles and high costs.
　　Driven by this challenge, a joint research team led by Prof. LIU Lizhuang from the Shanghai Advanced Research Institute (SARI) of the Chinese Academy of Sciences proposed a deep learning model named TransLNP, which based on self-attention mechanisms that maps the three-dimensional microstructure and biochemical properties of mRNA-LNPs to enable high-precision automated screening of LNPs.
　　The research findings were published in Briefings in Bioinformatics.
　　The designed TransLNP used a cross-molecule automatic learning approach to extract knowledge from existing molecular data, enabling small-sample training for LNPs and facilitating model transfer across different molecule types.
　　Figure 1 The overall architecture of TransLNP (Image by SARI)
　　To construct the mapping relationship between the 3D microstructure and biochemical properties of mRNA-LNPs, the model fully leveraged coarse-grained atomic sequence information and fine-grained atomic spatial correspondences. It extractd molecular-level features through the interaction of atomic information (atom types, coordinates, relative distance matrices, edge type matrices) based on a self-attention mechanism.
　　To address the imbalance caused by limited LNP data, scientists designed the BalMol (balance molecule) module. This module balanced the data by smoothing label distributions and molecular feature distributions. TransLNP achieved a mean squared error (MSE) of less than 5 for predicting LNP transfection efficiency. Compared with various mainstream graph convolutional neural networks and machine learning algorithms, TransLNP showd superior performance in terms of MSE, R2 (the larger the value, the better), and Pearson correlation coefficient, achieving top-tier metrics in the field.
　　This work is helpful for the rapid and accurate prediction of mRNA-LNP transfection efficiency and the prediction of new lipid nanoparticle structures, and sheds light on the application of mRNA drugs in gene therapy, vaccine development, and drug delivery.
　　

2024-06-07 more+