Highly Stable Mo-NiO@NiFe-Layered Double Hydroxide Heterojunction Anode Catalyst for Alkaline Electrolyzers with Porous Membrane.

Heterostructure catalysts are considered as promising candidates for promoting the oxygen evolution reaction (OER) process due to their strong electron coupling. However, the inevitable dissolution and detachment of the heterostructure catalysts are caused by the severe reconstruction, dramatically limiting their industrial application. Herein, the NiFe-layered double hydroxide (LDH) nanosheets attached on Mo-NiO microrods (Mo-NiO@NiFe LDH) by the preoxidation strategy of the core NiMoN layer are synthesized for ensuring the high catalytic performance and stability. Owing to the enhanced electron coupling and preoxidation process, the obtained Mo-NiO@NiFe LDH exhibits a superlow overpotential of 253 mV to achieve a practically relevant current density of 1000 mA cm-2 for OER with exceptional stability over 1200 h. Notably, the overall water splitting system based on Mo-NiO@NiFe LDH reveals remarkable stability, maintaining the catalytic activity at a current density of 1000 mA cm-2 for 140 h under industrial harsh conditions. Furthermore, the Mo-NiO@NiFe LDH demonstrates outstanding activity and long-term durability in a practical alkaline electrolyzer assembly with a porous membrane, even surpassing the performance of IrO2. This work provides a new sight for designing and synthesizing highly stable heterojunction electrocatalysts, further promoting and realizing the industrial electrocatalytic OER.

Hetero-Diatomic CoN4-NiN4 Site Pairs with Long-Range Coupling as Efficient Bifunctional Catalyst for Rechargeable Zn-Air Batteries.

In this study, Co/Ni-NC catalyst with hetero-diatomic Co/Ni active sites dispersed on nitrogen-doped carbon matrix is synthesized via the controlled pyrolysis of ZIF-8 containing Co2+ and Ni2+ compounds. Experimental characterizations and theoretical calculations reveal that Co and Ni are atomically and uniformly dispersed in pairs of CoN4-NiN4 with an intersite distance ≈0.41 nm, and there is long-range d-d coupling between Co and Ni with more electron delocalization for higher bifunctional activity. Besides, the in situ grown carbon nanotubes at the edges of the catalyst particles allow high electronic conductivity for electrocatalysis process. Electrochemical evaluations demonstrate the superior ORR and OER bifunctionality of Co/Ni-NC catalyst with a narrow potential gap of only 0.691 V and long-term durability, significantly prevailing over the single-atom Co-NC and Ni-NC catalysts and the benchmark Pt/C and RuO2 catalysts. Co/Ni-NC catalyzed Zn-air batteries achieve a high specific capacity of 771 mAh g-1 and a long continuous operation period up to 340 h with a small voltage gap of ≈0.65 V, also much superior to Pt/C-RuO2.

EGFR Oncogenic Mutations in NSCLC Impair Macrophage Phagocytosis and Mediate Innate Immune Evasion Through Up-Regulation of CD47.

INTRODUCTION: EGFR-mutated NSCLC is characterized by an immunosuppressive microenvironment that confers limited clinical effectiveness to anti-PD-1 or PD-L1 antibodies. Despite the discouraging outcomes of immunotherapy, novel immune checkpoints are constantly emerging, among which the specific vulnerability for therapeutic intervention in the context of EGFR-mutated NSCLC remains unresolved. METHODS: Data sets of patient- and cell line-levels were used for screening and mutual validation of association between EGFR mutation and a panel of immune checkpoint-related genes. Regulatory mechanism was elucidated through in vitro manipulation of EGFR signaling pathway and evaluated by immunoblot analysis, quantitative polymerase chain reaction, flow cytometry, immunofluorescence staining, and chromatin immunoprecipitation. In vivo investigation of different therapeutic strategies were conducted using both immunocompetent and immunodeficient mouse models. RESULTS: Among all screened immune checkpoints, CD47 emerged as the candidate most relevant to EGFR activation. Mechanistically, EGFR mutation constitutively activated downstream ERK and AKT pathways to respectively up-regulate the transcriptional factors c-Myc and NF-κB, both of which structurally bound to the promotor region of CD47 and actively transcribed this "don't eat me" signal. Impaired macrophage phagocytosis was observed on introduction of EGFR-sensitizing mutations in NSCLC cell line models, whereas CD47 blockade restored the phagocytic capacity and augmented tumor cell killing in both in vitro and in vivo models. Remarkably, the combination of anti-CD47 antibody with EGFR tyrosine kinase inhibitor revealed an additive antitumor activity compared with monotherapy of either antitumor agent in both immunocompetent and adaptive immunity-deficient mouse models. CONCLUSIONS: EGFR-sensitizing mutation facilitates NSCLC's escape from innate immune attack through up-regulating CD47. Combination therapy incorporating CD47 blockade holds substantial promise for clinical translation in developing more effective therapeutic approaches against EGFR-mutant NSCLC.

Superhydrophilic and Antifriction Thin Hydrogel Formed under Mild Conditions for Medical Bare Metal Guide Wires.

Medical guide wires play a crucial role in the process of intravascular interventional therapy. However, it is essential for bare metal guide wires to possess both hydrophilic lubricity and coating durability, avoiding tissue damage caused by friction inside the blood vessel during the interventional procedure. Additionally, it is still a huge challenge for diverse metal materials to bind with polymer coatings easily. Herein, we present a hydrogel coating scheme and its preparation method for various wires under mild conditions for environmental protection purposes. The preparation process involves surface pretreatment, including low-temperature heating and silanization, followed by a two-step dip coating and ultraviolet polymerization. The whole process leads to the formation of an interpenetrating cross-linked hydrogel network from the substrate to the surface section. This study confirms the superhydrophilicity and lubricity of three metal wires with the designed coating, especially reducing the friction significantly by ≥ 95%. The thin coating (average thickness <6.2 µm) demonstrates strong adhesion with various substrates and exhibits resistance to 25 or even 125 cycles of friction, indicating excellent stability and preventing easy detachment. The finally prepared composite nickel-titanium (NiTi) guide wire with stainless steel (SS) and platinum-tungsten (Pt-W) coils (overall diameter of ∼0.36 mm) shows satisfactory performance with a friction of 0.183 N for 25 cycles, meeting the clinical requirements (average friction ≤0.2 N) for interventional operation. These findings highlight the potential of this study in advancing the development of medical devices, particularly in the field of intravascular interventional therapy.

Genetically engineered PD-1 displaying nanovesicles for synergistic checkpoint blockades and chemo-metabolic therapy against non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) remains the most frequently diagnosed lung cancer and the leading cause of cancer-related mortality worldwide. PD-1/PD-L1 axis inhibitors have changed the treatment paradigm for various cancer types, including NSCLC. However, success of these inhibitors in lung cancer clinic is severely limited by their inability to inhibit the PD-1/PD-L1 signaling axis due to heavy glycosylation and heterogeneity expression of PD-L1 in NSCLC tumor tissue. Taking advantage of the facts that tumor cell derived nanovesicles could efficiently accumulate in the homotypic tumor sites due to their innate targeting abilities and that specific and high affinity existed between PD-1 and PD-L1, we developed NSCLC targeting biomimetic nanovesicles (NV) cargos from genetically engineered NSCLC cell lines that overexpressed PD-1 (P-NV). We showed that P-NVs efficiently bound NSCLC cells in vitro and targeted tumor nodules in vivo. We further loaded P-NVs with 2-deoxy-D-glucose (2-DG) and doxorubicin (DOX), and found that these drugs co-loaded P-NVs efficiently shrank lung cancers in mouse models for both allograft and autochthonous tumor. Mechanistically, drug-loaded P-NVs efficiently caused cytotoxicity to tumor cells and simultaneously activated anti-tumor immunity function of tumor-infiltrating T cells. Our data therefore strongly argue that 2-DG and DOX co-loaded, PD-1-displaying nanovesicles is a highly promising therapy for treatment of NSCLC in clinic. STATEMENT OF SIGNIFICANCE: Lung cancer cells overexpressing PD-1 are developed for preparing nanoparticles (P-NV). PD-1s displayed on NVs enhance their homologous targeting abilities to tumor cells expressing PD-L1s. Chemotherapeutics such as DOX and 2-DG, are packaged in such nanovesicles (PDG-NV). These nanovesicles efficiently delivered chemotherapeutics to tumor nodules specifically. The synergy between DOX and 2-DG is observed in inhibiting lung cancer cells in vitro and in vivo. Importantly, 2-DG causes deglycosylation and downregulation of PD-L1 on tumor cells while PD-1 displayed on nanovesicles' membrane blocks PD-L1 on tumor cells. 2-DG loaded nanoparticles thus activate anti-tumor activities of T cells in the tumor microenvironment. Our work thus highlights the promising antitumor activity of PDG-NVs, which warrants further clinical evaluation.

Dislocated Bilayer MOF Enables High-Selectivity Photocatalytic Reduction of CO2 to CO.

The highly selective photoreduction of CO2 into valuable small-molecule chemical feedstocks such as CO is an effective strategy for addressing the energy crisis and environmental problems. However, it remains a challenge because the complex CO2 photoreduction process usually generates multiple possible products and requires a subsequent separation step. In this paper, 2D monolayer and bilayer porphyrin-based metal-organic frameworks (MOFs) are successfully constructed by adjusting the reaction temperature and solvent polarity with 5,10,15,20-tetrakis(4-pyridyl)porphyrin as the light-harvesting ligand. The bilayer MOF is a low-dimensional MOF with a special structure in which the upper and lower layers are arranged in dislocation and are bridged by halogen ions. This bilayer MOF exhibits 100% ultra-high selectivity for the reduction of CO2 to CO under simulated sunlight without any cocatalyst or photosensitizer and can be recycled at least three times. The intrinsic mechanism of this photocatalytic CO2 reduction process is explored through experimental characterization and density functional theory (DFT) calculations. This work shows that the rational design of the number of layers in 2D MOF structures can tune the stability of these structures and opens a new avenue for the design of highly selective MOF photocatalysts.

Oriented External Electric Fields Regurating the Reaction Mechanism of CH4 Oxidation Catalyzed by Fe(IV)-Oxo-Corrolazine: Insight from Density Functional Calculations.

Methane is the simplest alkane and can be used as an alternative energy source for oil and coal, but the greenhouse effect caused by its leakage into the air is not negligible, and its conversion into liquid methanol not only facilitates transportation, but also contributes to carbon neutrality. In order to find an efficient method for converting methane to methanol, CH4 oxidation catalyzed by Fe(IV)-Oxo-corrolazine (Fe(IV)-Oxo-Cz) and its reaction mechanism regulation by oriented external electric fields (OEEFs) are systematically studied by density functional calculations. The calculations show that Fe(IV)-Oxo-Cz can abstract one H atom from CH4 to form the intermediate with OH group connecting on the corrolazine ring, with the energy barrier of 25.44 kcal mol-1. And then the product methanol is formed through the following rebound reaction. Moreover, the energy barrier can be reduced to 20.72 kcal mol-1 through a two-state reaction pathway. Furthermore, the effect of OEEFs on the reaction is investigated. We found that OEEFs can effectively regulate the reaction by adjusting the stability of the reactant and the transition state through the interaction of electric field-molecular dipole moment. When the electric field is negative, the energy barrier of the reaction decreases with the increase of electric intensity. Moreover, the OEEF aligned along the intrinsic Fe‒O reaction axis can effectively regulate the ability of forming the OH on the corrolazine ring by adjusting the charges of O and H atoms. When the electric field intensity is -0.010 a.u., the OH can be directly rebounded to the CH3· before it is connecting on the corrolazine ring, thus forming the product directly from the transition state without passing through the intermediate with only an energy barrier of 17.34 kcal mol-1, which greatly improves the selectivity of the reaction.

The High-Effective Catalytic Degradation of Benzo[a]pyrene by Mn-Corrolazine Regulated by Oriented External Electric Field: Insight From DFT Study.

The degradation of BaP into hydroxybenzo[a]pyrene by Mn-corrolazine and its regulation by an oriented external electronic field (OEEF) were systematically studied using first-principle calculations. Extensive density function calculations showed that the degradation of BaP into hydroxybenzo[a]pyrene by Mn-corrolazine occurs via a three-step process in the absence of OEEF, in which a more toxic and stable epoxide intermediate is generated. However, upon application of OEEF along the intrinsic Mn-O reaction axis, the degradation of BaP into hydroxybenzo[a]pyrene is greatly simplified. The negative charge on the terminal O atom of Mn-OO corrolazine increases with an increase in the OEEF intensity. As the intensity of the OEEF increases over 0.004 a.u., the negatively charged terminal O atom has the ability to directly abstract the positively charged H atom of BaP and the degradation of BaP into hydroxybenzo[a]pyrene can be completed via a one-step process, avoiding the production of more toxic epoxide intermediates.

Zirconium-oxo Nodes of MOFs with Tunable Electronic Properties Provide Effective ⋠OH Species for Enhanced Methane Hydroxylation.

Direct conversion of methane to high value-added oxygenates under mild conditions has attracted extensive interest. However, the over-oxidation of target products is usually unavoidable due to the easily excessive activation of C-H bond on the sites of supported metal species. Here, we identified the most efficient Zr-oxo nodes of UiO-66 metal-organic frameworks (MOFs) catalysts for the selective oxidation of methane with H2 O2 . These nodes were modified by three types of benzene 1, 4-dicarboxylates (NH2 -BDC, H2 BDC, and NO2 -BDC). Detailed characterizations and DFT calculations revealed that these ligands can effectively tune the electronic properties of Zr-oxo nodes and the H2 BDC ligand led to optimal electronic density of Zr-oxo nodes in UiO-66. Thus the UiO-66-H catalyst promoted the formation of ⋅OH species that adsorbed on Zr-oxo nodes, and facilitated the activation of methane with a lower energy barrier and subsequent conversion to hydroxylation oxygenates with 100 % selectivity.

Carfilzomib modulates tumor microenvironment to potentiate immune checkpoint therapy for cancer.

Impressive clinical benefit is seen in clinic with PD-1 inhibitors on portion of cancer patients. Yet, there remains an urgent need to develop effective synergizers to expand their clinical application. Tumor-associated macrophage (TAM), a type of M2-polarized macrophage, eliminates or suppresses T-cell-mediated anti-tumor responses. Transforming TAMs into M1 macrophages is an attractive strategy of anti-tumor therapy. Here, we conducted a high-throughput screening and found that Carfilzomib potently drove M2 macrophages to express M1 cytokines, phagocytose tumor cells, and present antigens to T cells. Mechanistically, Carfilzomib elicited unfolded protein response (UPR), activated IRE1α to recruit TRAF2, and activated NF-κB to transcribe genes encoding M1 markers in M2 macrophages. In vivo, Carfilzomib effectively rewired tumor microenvironment through reprogramming TAMs into M1-like macrophages and shrank autochthonous lung cancers in transgenic mouse model. More importantly, Carfilzomib synergized with PD-1 antibody to almost completely regress autochthonous lung cancers. Given the safety profiles of Carfilzomib in clinic, our work suggested a potentially immediate application of combinational treatment with Carfilzomib and PD-1 inhibitors for patients with solid tumors.

Targeting hyperactive TGFBR2 for treating MYOCD deficient lung cancer.

Purpose: Clinical success of cancer therapy is severely limited by drug resistance, attributed in large part to the loss of function of tumor suppressor genes (TSGs). Developing effective strategies to treat those tumors is challenging, but urgently needed in clinic. Experimental Design: MYOCD is a clinically relevant TSG in lung cancer patients. Our in vitro and in vivo data confirm its tumor suppressive function. Further analysis reveals that MYOCD potently inhibits stemness of lung cancer stem cells. Mechanistically, MYOCD localizes to TGFBR2 promoter region and thereby recruits PRMT5/MEP50 complex to epigenetically silence its transcription. Conclusions: NSCLC cells deficient of MYOCD are particularly sensitive to TGFBR kinase inhibitor (TGFBRi). TGFBRi and stemness inhibitor synergize with existing drugs to treat MYOCD deficient lung cancers. Our current work shows that loss of function of MYOCD creates Achilles' heels in lung cancer cells, which might be exploited in clinic.

Theoretical Understandings of Graphene-based Metal Single-Atom Catalysts: Stability and Catalytic Performance.

Research on heterogeneous single-atom catalysts (SACs) has become an emerging frontier in catalysis science because of their advantages in high utilization of noble metals, precisely identified active sites, high selectivity, and tunable activity. Graphene, as a one-atom-thick two-dimensional carbon material with unique structural and electronic properties, has been reported to be a superb support for SACs. Herein, we provide an overview of recent progress in investigations of graphene-based SACs. Among the large number of publications, we will selectively focus on the stability of metal single-atoms (SAs) anchored on different sites of graphene support and the catalytic performances of graphene-based SACs for different chemical reactions, including thermocatalysis and electrocatalysis. We will summarize the fundamental understandings on the electronic structures and their intrinsic connection with catalytic properties of graphene-based SACs, and also provide a brief perspective on the future design of efficient SACs with graphene and graphene-like materials.

Dual Metal Active Sites in an Ir1 /FeOx Single-Atom Catalyst: A Redox Mechanism for the Water-Gas Shift Reaction.

Herein, we report a theoretical and experimental study of the water-gas shift (WGS) reaction on Ir1 /FeOx single-atom catalysts. Water dissociates to OH* on the Ir1 single atom and H* on the first-neighbour O atom bonded with a Fe site. The adsorbed CO on Ir1 reacts with another adjacent O atom to produce CO2 , yielding an oxygen vacancy (Ovac ). Then, the formation of H2 becomes feasible due to migration of H from adsorbed OH* toward Ir1 and its subsequent reaction with another H*. The interaction of Ir1 and the second-neighbouring Fe species demonstrates a new WGS pathway featured by electron transfer at the active site from Fe3+ -O⋅⋅⋅Ir2+ -Ovac to Fe2+ -Ovac ⋅⋅⋅Ir3+ -O with the involvement of Ovac . The redox mechanism for WGS reaction through a dual metal active site (DMAS) is different from the conventional associative mechanism with the formation of formate or carboxyl intermediates. The proposed new reaction mechanism is corroborated by the experimental results with Ir1 /FeOx for sequential production of CO2 and H2 .

Discovery of Novel Inhibitor for WNT/ß-Catenin Pathway by Tankyrase 1/2 Structure-Based Virtual Screening.

Aberrant activation of the WNT/ß-catenin signaling pathway is implicated in various types of cancers. Inhibitors targeting the Wnt signaling pathway are intensively studied in the current cancer research field, the outcomes of which remain to be determined. In this study, we have attempted to discover novel potent WNT/ß-catenin pathway inhibitors through tankyrase 1/2 structure-based virtual screening. After screening more than 13.4 million compounds through molecular docking, we experimentally verified one compound, LZZ-02, as the most potent inhibitor out of 11 structurally representative top hits. LiCl-induced HEK293 cells containing TOPFlash reporter showed that LZZ-02 inhibited the transcriptional activity of ß-catenin with an IC50 of 10 ± 1.2 µM. Mechanistically, LZZ-02 degrades the expression of ß-catenin by stabilizing axin 2, thereby diminishing downstream proteins levels, including c-Myc and cyclin D1. LZZ-02 also inhibits the growth of colonic carcinoma cell harboring constitutively active ß-catenin. More importantly, LZZ-02 effectively shrinks tumor xenograft derived from colonic cell lines. Our study successfully identified a novel tankyrase 1/2 inhibitor and shed light on a novel strategy for developing inhibitors targeting the WNT/ß-catenin signaling axis.

IRF8 induces senescence of lung cancer cells to exert its tumor suppressive function.

Lung cancer is the leading cause of cancer-related deaths worldwide. However, tumor suppressor genes remain to be systemically determined for lung cancer. Here we report interferon regulatory factor 8 (IRF8), a member of the IRF family of transcription factors, as a potent lung tumor suppressor gene. Expression of IRF8 is frequently diminished in lung tumoral tissues and is associated with prognosis of non-small cell lung cancer (NSCLC) patients. Ectopic expression of IRF8 suppresses the NSCLC cells proliferation in vitro and tumorigenic potential in vivo. More importantly, forced expression of IRF8 through infection of recombinant virus inhibits lung tumorigenesis in genetically engineered mouse model (GEMM). Mechanistically, IRF8 inhibits AKT signaling and promotes accumulation of P27 protein, which results in senescence of lung cancer cells. Ectopic expression of IRF8 in tumor cells leads to regression of lung cancer tumor nodules in a xenograft tumor model. Our data, therefore, solidly shows IRF8 to be a lung cancer suppressor gene and may denote an opportunity for therapeutic intervention of NSCLC.

Theoretical investigation on the electronic structure of one dimensional infinite monatomic gold wire: insights into conducting properties.

Mixed-valence metal-organic nanostructures show unusual electronic properties. In our pervious investigation, we have designed and predicted a unique one-dimensional infinite monatomic gold wire (1D-IMGW) with excellent conductivity and the interesting characteristic of mixed valency (Auc 3+ and Au0 i). For further exploring its conduction properties and stability in conducting state, here we select one electron as a probe to explore the electron transport channel and investigate its electronic structure in conducting state. Density functional theory (DFT) calculations show the 1D-IMGW maintains its original structure in conducting state illustrating its excellent stability. Moreover, while adding an electron, 1D-IMGW is transformed from a semiconductor to a conductor with the energy band mixed with Auc (5d) and Aui (6s) through the Fermi level. Thus 1D-IMGW will conduct along its gold atom chain demonstrating good application prospect in nanodevices.

Theoretical investigation of an ultrastable one dimensional infinite monatomic mixed valent gold wire with excellent electronic properties.

Gold nanowires have attracted considerable attention owing to their potential applications in mesoscopic research and nanodevices. However, monatomic Au long chains are naturally metastable, making it difficult to use them directly in these applications. Herein, a unique one-dimensional (1D) infinite monatomic gold wire (1D-IMGW) was designed, and its electronic and optical properties were characterized by density functional theory (DFT) calculations. The 1D-IMGW was stabilized by corrole rings, and there were strong interactions between the dz(2) orbitals of the Auc atoms in the centers of the corrole rings and the 6s orbitals of the Aui atoms in the middle of adjacent corrole rings. The excellent conductivity of one-dimensional metal nanowires was observed along the Au wire perpendicular to the corrole rings. Moreover, the 1D-IMGW demonstrated the unique characteristic of mixed valences (Au(3+) and Au(0)) and exhibited strong absorption across the entire visible range.

The O, OH and OOH-assisted selective coupling of methanol on Au-Ag(111).

Using density functional theory (DFT) calculations, we performed a thorough theoretical investigation on the catalytic mechanism of oxidative self-coupling of methanol with molecular oxygen on Au-Ag catalysts. It is found that molecular oxygen can be activated via a hydroperoxyl (OOH) intermediate by taking a hydrogen atom from co-adsorbed methanol with an energy barrier of 0.51 eV, which is actually the rate determining step for the overall reaction. The O, OH and OOH oxidant formation proceeds via two channels of I and II with low barriers. We demonstrated that the oxidative coupling of methanol by OOH, atomic oxygen, and hydroxyl is much more favorable than the total oxidation of methanol, and is responsible for the high selectivity of Au-Ag catalysts in methanol oxidation. The revealed activation mechanism provides an efficient pathway for optimizing the selective coupling of methanol with dioxygen.

Theoretical Investigation of Promising Molecules for Obtaining Complexes with Planar Tetracoordinate Carbon.

We have theoretically investigated the stability, chemical bonding, and coordination ability of the 2-Me-2-borabicyclo[1.1.0]but-1(3)-ene (2-Me-2BB) molecule using density functional theory and ab initio molecular dynamics (AIMD) simulations. Calculated results indicated that 2-Me-2BB is both thermodynamically and kinetically stable. The C=C bonds in 2-Me-2BB contain a π bond and a charge shift (CS) bond, different from those in 1-Me-borirene and cyclopropylene. Moreover, 2-Me-2BB can be a σ donor, leading to the formation of TM(2-Me-2BB)L n complexes containing planar tetracoordinate carbon (ptC) with transition metals (TM = Sc-Cu), in which the lone electron pair of 2-Me-2BB results from its ionic resonance form. The lengths and Wiberg bond indices of the TM-ptC bond in TM(2-Me-2BB)L n (TM = Sc-Cu) reveal that 2-Me-2BB can be a ligand similar to N-heterocyclic carbene. Therefore, 2-Me-2BB and its derivatives are promising molecules to obtain complexes with ptC. The natural charges on TM atoms in TM(2-Me-2BB)L n (TM = Sc-Cu) complexes range from -0.97 to 1.54e, indicating that such complexes with ptC might have potential applications in catalytic chemistry.

Catalysis on singly dispersed bimetallic sites.

A catalytic site typically consists of one or more atoms of a catalyst surface that arrange into a configuration offering a specific electronic structure for adsorbing or dissociating reactant molecules. The catalytic activity of adjacent bimetallic sites of metallic nanoparticles has been studied previously. An isolated bimetallic site supported on a non-metallic surface could exhibit a distinctly different catalytic performance owing to the cationic state of the singly dispersed bimetallic site and the minimized choices of binding configurations of a reactant molecule compared with continuously packed bimetallic sites. Here we report that isolated Rh1Co3 bimetallic sites exhibit a distinctly different catalytic performance in reduction of nitric oxide with carbon monoxide at low temperature, resulting from strong adsorption of two nitric oxide molecules and a nitrous oxide intermediate on Rh1Co3 sites and following a low-barrier pathway dissociation to dinitrogen and an oxygen atom. This observation suggests a method to develop catalysts with high selectivity.