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Carbon-dots with unique physical and chemical properties have versatile applications in environmental and energy fields.

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Syngas, a CO and H2 mixture mostly generated from non-renewable fossil fuels, is an essential feedstock for production of liquid fuels. Electrochemical reduction of CO2 and H+/H2O is an alternative renewable route to produce syngas. Here we introduce the concept of coupling a hydrogen evolution reaction (HER) catalyst with a CDots/C3N4 composite (a CO2 reduction catalyst) to achieve a cheap, stable, selective and efficient route for tunable syngas production. Co3O4, MoS2, Au and Pt serve as the HER component. The Co3O4-CDots-C3N4 electrocatalyst is found to be the most efficient among the combinations studied. The H2/CO ratio of the produced syngas is tunable from 0.07:1 to 4:1 by controlling the potential. This catalyst is highly stable for syngas generation (over 100 h) with no other products besides CO and H2. Insight into the mechanisms balancing between CO2 reduction and H2 evolution when applying the HER-CDots-C3N4 catalyst concept is provided.

Noble-metal clusters are important catalysts because of their unique structures and activities, which are associated with their metalÀmetal bonds.[1] Numerous methods have been developed to encapsulate metal clusters within porous materials or polymers to protect the clusters against sintering.[2] A common porous support is zeolite, owing to its intrinsic subnanometer pore diameters, which are similar to the size of the metal clusters and can confine and prevent the clusters from growing into big particles. This confinement allows metal clusters to activate reactants with small molecular sizes that are accessible to the pores. [3] Mesoporous silica provides an ideal support, owing to its large pore diameters, which are suitable for large-sized organic substrates and biomass derivatives.[4] Ligand-stabilized metal precursors are usually used to anchor the clusters within the mesoporous channel with a low loading of the metal.[5] Uniform mesoporous-silica-supported noble-metal clusters cannot be achieved by impregnation of the support in an aqueous solution of the metal salts because the pore diameter of mesoporous silica (> 2 nm) is larger than the size of the metal clusters. The metal clusters are easily grown into big particles with a broad size distribution.[6] The incorporation of heteroelements (Zr, Ti, Al, etc.) into mesoporous silica has been developed to disperse metal species.[7] However, some metal particles still migrate towards the outside of the support during the reduction step with hydrogen, which causes their aggregation into big particles and, hence, the blocking of the entrance to the pore channels. Therefore, substantial challenges remain towards the goal of synthesizing uniform metal clusters that are immobilized within mesoporous silica from the corresponding metal salts.Biomass becomes an increasingly important feedstock to produce fuels and chemicals for a sustainable future.[8] Furan derivatives have been identified as the key building blocks to synthesize valuable chemicals.[9] Besides its nontoxic and nonflammable properties, water is a desirable solvent because the furan derivatives are soluble under aqueous conditions.[10] Several catalysts have been developed for the hydrogenation of furan derivatives in water, but high reaction temperatures or high hydrogen pressures are required to achieve high activities because of the low aqueous solubility of hydrogen. [11] Herein, immobilized ruthenium clusters (50 Ru atoms) in nanosized mesoporous zirconium silica (MSN-Zr) were synthesized by using an impregnation method, starting from an aqueous solution of RuCl 3 . The Ru cluster catalyst showed remarkable activity for hydrogenation of furan derivatives in water at room temperature under 5 bar hydrogen pressure.MSN-Zr-x, which has a uniform hexagonal pore structure, was synthesized by modification of our previously reported two-step procedure, [12] in which x denotes the Si/Zr molar ratio (for the detailed preparation, see the Supporting Information). The morphology and pore structure are sim...

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Broad spectrum Bcl-2 small molecule inhibitors act as BH3 mimetics are effective antitumor agents. Herein, we have identified S1, a previously discovered small molecule Bcl-2 inhibitor, as the first authentic BH3 mimetic as well as a dual, nanomolar inhibitor of Bcl-2 and Mcl-1 (K i 5 310 nM and 58 nM, respectively). The results of fluorescence polarization assays, coimmunoprecipitation, fluorescent resonance energy transfer, and shRNA indicated that S1 can disrupt Bcl-2/Bax, Mcl-1/Bak and Bcl-2/Bim heterodimerization in multiple cell lines, activate Bax accompanied by its translocation to mitochondrial, activate caspase 3 completely dependent on Bax/Bak, and in turn induce a Bim-independent apoptosis. Moreover, S1 could induce apoptosis on the primary acute lymphoblastic leukemia cells regardless of Mcl-1 level. Mechanism-based single agent antitumor activity in a mouse xenograft H22 (mouse liver carcinoma) model ascertain its therapeutic potential. S1 represents a novel chemical class of antitumor leads that function solely as BH3 mimetics and pan-Bcl-2 inhibitors. In the meanwhile, S1 could become a unique tool for interactions between Bcl-2 family proteins.

Controlling the reaction selectivity of a heterobifunctional molecule is a fundamental challenge in many catalytic processes. Recent efforts to design chemoselective catalysts have focused on modifying the surface of metal nanoparticle materials having tunable properties. However, precise control over the surface properties of base-metal oxide catalysts remains a challenge. Here, we show that green modification of the surface with carboxylates can be used to tune the ammoxidation selectivity toward the desired products during the reaction of hydroxyaldehyde on manganese oxide catalysts. These modifications improve the selectivity for hydroxynitrile from 0 to 92% under identical reaction conditions. The product distribution of dinitrile and hydroxynitrile can be continuously tuned by adjusting the amount of carboxylate modifier. This property was attributed to the selective decrease in the hydroxyl adsorption affinity of the manganese oxides by the adsorbed carboxylate groups. The selectivity enhancement is not affected by the tail structure of the carboxylic acid.