Preliminary Investigation on Laser Ultrasonic NDE of Nano-meter Materials

Some experimental results about laser ultrasonic NDE of nano-meter materials of silver and copper (hereafter nmAg and nmCu) are obtained. A pulsed laser is used as the ultrasonic source, and a capacitive transducer as the receiver. The phenomenon related to the particle size effect and the interface effect between particles of nano-mater material is observed. The response signal resulting from artificial interface layer in nmCu is clearly seen

NiO Matrix Decorated by Ru Single Atoms: Electron-Rich Ru-Induced High Activity and Selectivity toward Electrochemical N₂ Reduction

Developing a single-atom catalyst with electron-rich active sites is a promising strategy for catalyzing the electrochemical N2 reduction reaction (NRR). Herein, we choose NiO(001) as a model template and deposit a series of single transition metal (TM) atoms with higher formal charges to create the electron-rich active centers. Our first-principles calculations show that low-valent Ru (+2) on NiO(001) can significantly activate N2, with its oxidation states varying from +2 to +4 throughout the catalytic cycle. The Ru/NiO(001) catalyst exhibits the best activity with a relatively low limiting potential of −0.49 V. Furthermore, under NRR operating conditions, the Ru site is primarily occupied by *N2 rather than *H, indicating that NRR overwhelms the hydrogen evolution reaction and thus exhibits excellent selectivity. Our work highlights the potential of designing catalysts with electron-rich active sites for NRR

In Situ Topotactic Transformation of an Interstitial Alloy for CO Electroreduction

Electrochemical reduction of CO to value-added products holds promise for storage of energy from renewable sources. Copper can convert CO into multi-carbon (C2+) products during CO electroreduction. However, developing a Cu electrocatalyst with a high selectivity for CO reduction and desirable production rates for C2+ products remains challenging. Herein, highly lattice-disordered Cu3N with abundant twin structures as a precursor electrocatalyst is examined for CO reduction. Through in situ activation during the CO reduction reaction (CORR) and concomitant release of nitrogen, the obtained metallic Cu° catalyst particles inherit the lattice dislocations present in the parent Cu3N lattice. The de-nitrified catalyst delivers an unprecedented C2+ Faradaic efficiency of over 90% at a current density of 727 mA cm−2 in a flow cell system. Using a membrane electrode assembly (MEA) electrolyzer with a solid-state electrolyte (SSE), a 17.4 vol% ethylene stream and liquid streams with concentration of 1.45 m and 230 × 10−3 m C2+ products at the outlet of the cathode and SSE-containment layer are obtained

In Situ Topotactic Transformation of an Interstitial Alloy for CO Electroreduction

Electrochemical reduction of CO to value-added products holds promise for storage of energy from renewable sources. Copper can convert CO into multi-carbon (C2+) products during CO electroreduction. However, developing a Cu electrocatalyst with a high selectivity for CO reduction and desirable production rates for C2+ products remains challenging. Herein, highly lattice-disordered Cu3N with abundant twin structures as a precursor electrocatalyst is examined for CO reduction. Through in situ activation during the CO reduction reaction (CORR) and concomitant release of nitrogen, the obtained metallic Cu° catalyst particles inherit the lattice dislocations present in the parent Cu3N lattice. The de-nitrified catalyst delivers an unprecedented C2+ Faradaic efficiency of over 90% at a current density of 727 mA cm−2 in a flow cell system. Using a membrane electrode assembly (MEA) electrolyzer with a solid-state electrolyte (SSE), a 17.4 vol% ethylene stream and liquid streams with concentration of 1.45 m and 230 × 10−3 m C2+ products at the outlet of the cathode and SSE-containment layer are obtained