The selective oxidation of hydrocarbons to the corresponding ketones with solvent-free and molecular oxygen as an oxidant is of great importance in academic and industrial fields in view of economy and environment.

Fretting damage failure analysis of a Chinese carbon railway axle RD2 was carried out. The wheel hub was in situ cut to expose the damaged surface of the wheel seat to avoid additional damage. A small‐scale axle test rig was developed, and simulation tests were performed at different rotator speeds of 1800 and 2100 rpm. The wear mechanism of fretting damage areas was a combination of abrasive wear, oxidative wear and delamination. The fracture surfaces exhibited characterization of multisource and step‐profile. The fretting fatigue crack initiated at the subsurface and propagated along an inclined angle at the first stage. The fretting damage at the higher speed was more severe compared with the lower speed, which lead to a relatively shorter fatigue life. The damage morphologies of the axle in the simulation tests were in good agreement with that observed in the failure analysis on real axle.

Platinum (Pt) is the most effective bench-marked catalyst for producing renewable and clean hydrogen energy by electrochemical water splitting. There is demand for high HER catalytic activity to achieve efficient utilization and minimize the loading of Pt in catalysts. In this work, we significantly boost the HER mass activity of Pt nanoparticles in Pt x /Co to 8.3 times higher than that of commercial Pt/C by using Co/NC heterojunctions as a heterogeneous version of electron donors. The highly coupled interfaces between Co/NC and Pt metal enrich the electron density of Pt nanoparticles to facilitate the adsorption of H + , the dissociation of Pt À H bonds and H 2 release, giving the lowest HER overpotential of 6.9 mV vs. RHE at 10 mA cm À2 in acid among reported HER electrocatalysts. Given the easy scale-up synthesis due to the stabilization of ultrafine Pt nanoparticles by Co/NC solid ligands, Pt x /Co can even be a promising substitute for commercial Pt/C for practical applications.

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A microporous oxalamide-functionalized NbO-type metal− organic framework, HNUST-3, has been designed and synthesized by selfassembling [Cu 2 (COO) 4 ] paddlewheel SBUs and a novel tetracarboxylate ligand with linking oxalamide groups. HNUST-3 represents the first example of a porous oxalamide-functionalized MOF, which exhibits a high BET surface area of 2412 m 2 •g −1 , large H 2 uptake (unsaturated total capacity of 6.1 wt % at 20 bar and 77 K), and excellent CH 4 storage (135.8 cm 3 (STP)cm −3 at 20 bar and 298 K) as well as high CO 2 adsorption capacity (20.2 mmol•g −1 at 20 bar and 298 K) with good selectivity for CO 2 over CH 4 (7.9) and N 2 (26.1) at 298 K.