NENU-MV-5 as a heterogeneous catalyst without any co-catalyst, one-step selective oxidative cleavage of lignin models to high-value-added aromatics in a single solvent was achieved by synergistic effect of VIV–O–VV and CuI using O2 as oxidant.

Oxygen reduction reaction underpins the development of the whole fuel-cell field, where there is a strong impetus to develop efficient and stable catalysts that can replace the precious metal Pt/C. Herein, a series of excellent catalysts for ORR derived from Ce/La dual lanthanide metal-organic framework with functional Lewis-basic sites were synthesized for the first time. The synergistic effect of high concentration of oxygen vacancies from La-embedded CeO and Fe-N sites as well as porous structure endows the catalyst superior performance to Pt/C, with a half-wave potential ( E) of 0.870 V and a current density ( j) of 5.43 mA/cm. Furthermore, the catalysts are also effective for other nonelectrocatalytic reactions. It is expected that this research will contribute to synthesis of an excellent nonplatinum electrocatalyst for fuel-cell applications, and the oxygen vacancies stabilized in carbon matrix offer a method for versatile catalyst design for other reactions.

Polyoxometalate (POM)-based metal–organic frameworks (MOFs) with nanostructure represent a class of promising heterogeneous nanocatalysts. As yet, direct one-step controllable synthesis of pure nanoscale POM-MOFs catalysts is an extremely huge challenge owing to highly complicated synthetic conditions. Herein, for the first time, we fabricated ultrathin (∼5 nm) mixed-valence {V16} clusters-incorporated metal–organic framework nanosheets [Ni­(4,4′-bpy)2]2 [V7 IVV9 VO38Cl]·(4,4′-bpy)·6H2O (NENU-MV-1a) via one-step template-free strategy and successfully achieved one-step removal of all impurities from the multicomponent complex system. The obtained NENU-MV-1a nanosheets possess dramatically different physiochemical properties from bulk crystal, including larger lateral area, and more active sites originated from their nanostructures. As a proof-of-concept application, NENU-MV-1a was applied in olefin epoxidation in air and exhibited more excellent catalytic activity (95% conversion) than the bulk crystal (35%). In addition, detailed catalytic mechanism studies revealed the structure–property correlations of NENU-MV-1a and proposed VIV–VV synergistic catalytic effect. Our investigations are of great significance for the development of more active and/or selective mixed-valence metal–oxygen cluster-based MOF nanocatalysts.

A pure-inorganic framework 1 underwent a SCSC transformation to form a new framework 1′, which has high proton conductivity.

Almost all proton-conducting materials display poor conductivity at subzero temperatures, which significantly limits their application in cold regions. Thus, effective strategies to achieve high proton conductivity in a wide range from subzero to medium temperatures (−40 to 85 °C) need to be developed. Herein, we prepared proton-conductive materials by encapsulating the acid–base adduct based on Keggin-type H3PW12O40 (HPW) and aminoethanesulfonic acid (C2H7O3NS, HSN) in the linear channels of SBA-15 (named HPW-HSN@SBA-15). The result is the same as we expected: HPW-HSN@SBA-15 exhibits high proton conductivity over a wide temperature range (−40 to 85 °C). The proton conductivity of 75 wt % HPW-HSN@SBA-15 (3HPW-HSN@SBA-15) reaches 0.16 S cm–1 at 85 °C, 97% relative humidity (RH), and 6.8 × 10–5 S cm–1 at −40 °C. The excellent proton conductivity at subzero temperature of HPW-HSN@SBA-15 is mainly attributed to the ultrafast proton transfer with low energy barrier between proton donor (acid group) and proton acceptor (base group) in acid–base adduct without the attendance of water. Furthermore, the proton conductivity cycle test of 3HPW-HSN@SBA-15 demonstrates its good durability and stability.