Designing polyoxometalate-based metal-organic framework for oxidation of styrene and cycloaddition of CO_(2) with epoxides

A photoactive polyoxometalate-based metal-organic framework (POMOF),NiW-DPNDI,was synthesized by combination of Ni(Ⅱ) ions,[ZnW_(12)O_(40)]^(6–)anions,and N,N’-bis(4-pyridylmethyl)naphthalene diimide(DPNDI) molecules into one single framework.Ni W-DPNDI displays a three-dimensional structure by the strong anion···π interactions between the trapped[ZnW_(12)O_(40)]^(6–)anions and the electron-deficient naphthalenic ring centroids and theπ-πstacking interactions between DPNDI moieties.Ni W-DPNDI displayed a highly efficient hole-electron separation and ordered electron transfer under irradiation,thus ensuing its excellent photocatalysis in oxidation of styrene to produce benzaldehyde.In addition,it gave a high efficiency for styrene oxide under thermocatalytic conditions.Because the carbonic anhydrase (CA)-mimicking Ni sites and the negative electron-enriched[ZnW_(12)O_(40)]^(6–)anions are well aligned in the pores,it can promote the cycloaddition of CO_(2) with epoxides under mild conditions.

Synthesis of lathanum or La-B doped KIT-6 mesoporous materials and their application in the catalytic oxidation of styrene

La-doped and La-B-doped KIT-6 mesoporous materials were prepared by direct hydrothermal synthesis with pH-adjusting method and characterized by X-ray diffractometer(XRD),nitrogen sorption,FT-IR,UV-Vis,X-ray photoelectron spectroscopy(XPS) and ICP-AES.The catalytic performance for the oxidation of styrene by hydrogen peroxide,tert-butyl hydroperoxide or oxygen was investigated.The results showed that the introduction of heteroatoms did not destroy the mesostructure of KIT-6 with cubic Ia3d space group.La or ...

Synthesis of amorphous Pd-based nanocatalysts for efficient alcoholysis of styrene oxide and electrochemical hydrogen evolution

Amorphous nanomaterials with long-range disordered structures could possess distinct properties and promising applications,especially in catalysis,as compared with their conventional crystalline counterparts.It is imperative to achieve the controlled preparation of amorphous noble metal-based nanomaterials for the exploration of their phase-dependent applications.Here,we report a facile wet-chemical reduction strategy to synthesize various amorphous multimetallic Pd-based nanomaterials,including PdRu,PdRh,and PdRuRh.The phase-dependent catalytic performances of distinct Pd-based nanomaterials towards diverse catalytic applications have been demonstrated.Specifically,the usage of PdRu nanocatalysts with amorphous and crystalline face-centered cubic(fcc)phases can efficiently switch the ring-opening route of styrene oxide to obtain different products with high selectivity through alcoholysis reaction and hydrogenation reaction,respectively.Moreover,when used as an electrocatalyst for hydrogen evolution reaction(HER),the synthesized amorphous PdRh nanocatalyst exhibits low overpotential and high turnover frequency values,outperforming its crystalline fcc counterpart and most of the reported Pd-based HER electrocatalysts.