Li Mengyang,Wu Yongmeng,Zhao Bo-Hang,Cheng Chuanqi,Zhao Jinghui,Liu Cuibo,Zhang Bin
Amino acids have wide application in the food and pharmaceutical industries. Current biotic and chemical syntheses suffer from low efficiency, complex purification operations and high energy consumption. Here we report a sustainable electrocatalytic synthesis of alanine from NO and pyruvic acid over oxide-derived Ag with low-coordination sites under ambient conditions. Mechanistic studies reveal a cascade NO → NH 2 OH → pyruvate oxime → alanine pathway. The quick pyruvate oxime formation and slow pyruvate oxime reduction steps cause various side reactions, leading to low alanine production. Then, a spatially decoupled two-pot electrosynthesis system using flow reactors loaded with oxide-derived Ag is designed for pyruvate oxime formation and reduction reactions. This decoupled system delivers 3.85 g of easily purified alanine with a total Faradaic efficiency of 70% and a purity of >98% at 100 mA cm −2 . Further techno-economic analysis demonstrates the potential. This method is suitable for solar-energy-driven alanine electrosynthesis from polylactic acid wastes and for the fabrication of other amino acids.
Achieving lightweight, high electrical conductivity remains a central challenge for flexible conductive coatings, especially within environmentally friendly solvent-free processing systems. Herein, a porous solvent-free polyurethane (SFPU) coating with a three-dimensional (3D) conductive network was successfully constructed employing thermally expandable microspheres (TEMs) as foaming agents and carbon nanotubes (CNTs) as conductive fillers. Owing to the volumetric expansion of TEMs during curing, the CNTs were squeezed into the gaps between the microspheres. As a result, the electrical conductivity of the coating with 4 wt% TEMs increased by 16.3 times and the density decreased by over 61% compared with non-foamed references, showing light-weight, flexibility (Strain of 125%) and sensitive conductivity (0.88 S/m) characteristics. At a low voltage of 5 V or a weak light intensity of 150 mW·cm −2 , the temperature of the coating surface reached 160 °C and 68 °C, respectively, and maintained for at least 30 min, showing efficient electrothermal and photothermal conversion performance. Moreover, this coating also exhibited a linear and reproducible resistance–temperature relationship (TCR ≈ -0.95%·°C −1 ), enabling real-time temperature monitoring and showing potential for fire hazard warning applications. Owing to the rough surface and porous conductive structure, the coating also exhibited multiple protective functionalities, including waterproofness, effective UV-blocking performance and electromagnetic interference shielding. This work presents a scalable route to flexible multifunctional conductive coatings and introduces a general porous structural design strategy for environmentally friendly coating systems.
Graphical The hierarchical TS-1 with abundant mesopores was prepared by TPAOH/TIPA treatment, which was applied to the reaction of the ammoximation-oxidation of acetone to 2-nitropropane. Hierarchical TS-1 catalyst performed excellent reusability and catalytic activity with 97.5 % conversion and 96.8 % selectivity. The novel technology for clean and mild synthesis of nitroalkanes has been developed. Modified TS-1 catalysts for the acetone ammoximation-oxidation reaction were prepared by post-treating TS-1 with different concentrations of TPAOH/TIPA, and the effects of alkali treatment on the catalytic performance were systematically investigated. The techniques such as XRD, SEM, TEM and N 2 sorption were used to characterize the catalyst samples, which exhibited that the introduction of alkali increased the volume and quantity of mesopores, while there was no obvious influence on the framework structure and titanium content in the framework. And the improvement in catalyst performance after alkali treatment was attributed to the increase of mesopores and the decrease in diffusion limitation. In addition, three common ammoximation catalysts (Ti-MOR, Ti- MWW and TS-1) were systematically investigated in this reaction. Ti-MOR showed superiority in the ammoximation to oxime, while TS-1 displayed the best catalytic performance in the ammoximation oxidation of ketones to nitroalkanes. It was indicated that modified TS-1 could be a promising catalyst for the ammoximation-oxidation reaction of acetone.
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