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This study proposes a straightforward strategy utilizing metal–organic frameworks (MOFs) to obtain efficient electrocatalysts for synthesizing C2 products (C2H4 and C2H5OH) via a CO2 reduction reaction. Cu-MOF-74 was chosen as the precursor, while copper oxide nanoparticles were obtained through a calcination method. During the calcination process, by controlling the calcination conditions, the porous structure of the MOF framework was successfully retained, leading to CuO-400 with a high catalytic activity and C2 production efficiency. Compared to CuO-n formed by the calcination of Cu(NO3)2, CuO-400 derived from MOFs exhibits a 1.6 times higher C2 activity as an electrocatalytic material at −1.15 V vs. RHE. [ABSTRACT FROM AUTHOR]

In this study, analysis of the chemical constituents and bioactivities of the unpolar fractions [petroleum ether (PE) and chloroform (C)] of fruits and leaves of Alpinia oxyphylla Miq. were carried out, as well as the bioactivities of the main compounds nootkatone and valencene. From PE and C fractions of the fruits, and PE fraction of the leaves, 95.80%, 59.30%, and 82.11% of the chemical constituents respectively were identified by GC-MS. Among these identified compounds, nootkatone was the main compound in all of three fractions, while valencene was the second main compound in the PE fractions of the fruits and leaves. The bioactivities results showed that all of the fractions and the major compound nootkatone showed tyrosinase inhibitory, as well as inhibitory effect on NO production in LPS-stimulated RAW264.7 cells. While valencene only presented inhibitory activity on NO production in RAW264.7 cells. The critical genes involved in nootkatone biosynthesis in A. oxyphylla were identified from the public transcriptome datasets, and protein sequences were preliminarily analyzed. Our studies develop the usage of the unpolar fractions of A. oxyphylla, especially its leaves as the waste during its production, and meanwhile provide the gene resources for nootkatone biosynthesis. [ABSTRACT FROM AUTHOR]

Nitrogen-rich hollow carbon microspheres were successfully synthesized using resorcinol and formaldehyde as carbon sources, tetraethylenepentamine (TEPA) as a catalyst, and nitrogen source, with SiO2 microspheres as a hollow template. The hollow carbon microspheres were prepared by adding varying amounts of SiO2 hollow templates to a fixed amount of TEPA. The shell thickness increased as the amount of SiO2 template decreased and the shell thicknesses of AHMCS-2(1), AHMCS-2(3), and AHMCS-2(5) were 28.5 nm, 17.3 nm, and 12.7 nm, respectively. The activated hollow carbon microspheres (AHMCS-2(1), AHMCS-2(3) and AHMCS-2(5)) contained 4.66%, 5.05%, and 3.27% nitrogen, respectively. Due to the sufficient activation process, the specific surface area and microporous volume of hollow carbon microspheres are greatly increased compared to solid carbon microspheres, therefore, their CO2 adsorption performance is superior as well. As the shell layer thickens, the specific surface area and micropore volume of the activated hollow carbon microspheres increased, among which AHMCS-2(1) showed the largest specific surface area and micropore volume of 1146 m2/g and 0.45 cm3/g, respectively. Similarly, the CO2 adsorption capacity of activated hollow carbon microspheres increased with the increasing thickness of the shell layer, and that of AHMCS-2(1) reached 5.54 mmol/g at 0 °C. High specific surface area, high micropore volume, high nitrogen content, and small micropore pore size are favorable for CO2 adsorption by carbon microspheres. The hollow carbon microspheres exhibit high CO2 dynamic adsorption capacity, excellent selective adsorption, and good cyclic stability. Highlights: Nitrogen-rich hollow carbon microspheres with different shell layer thicknesses were prepared using the template method. The thicker shell thickness retains more micropores and nitrogen content. The nitrogen-rich hollow carbon microspheres have high CO2 adsorption performance due to large specific surface area and high nitrogen content. The effect of activation process on the nitrogen-rich hollow carbon microspheres with different shell thicknesses is investigated. [ABSTRACT FROM AUTHOR]

The nitrogen-rich carbon microspheres were prepared by the one-pot hydrothermal synthesis in the presence of resorcinol formaldehyde as the carbon precursor and tetraethylenepentamine (TEPA) as nitrogen precursor as well as the base catalyst, followed by carbonization and activation. Their nitrogen content and microstructure of the nitrogen-rich carbon microspheres could be adjusted by varying the addition of TEPA. The significant enhancement of the microstructure and the nitrogen doping leads to high CO2 adsorption in the activated carbon microspheres. The high nitrogen content of activated sample AMPS-4 was 5.61%, and the large specific surface area and micropore volume were 786.5 m2/g and 0.28 cm3/g, respectively. The activated sample AMCS-4 had the highest CO2 adsorption reaching 5.52 mmol/g and 2.97 mmol/g at 0 and 25 °C, respectively. Compared with EDA-prepared carbon microspheres AMCS-4E, TEPA-prepared carbon microspheres AMCS-4 have stabler chemical adsorption to CO2 due to their higher nitrogen content, which is in corresponds to the higher adsorption heat. The introduction of polyvinylpyrrolidone (PVP) into the system as a stabilizer not only improved the monodispersity of carbon microspheres but also improved the adsorption performance of CO2 by increasing the micropore volume and decreasing the micropore size of the microspheres. The CO2 adsorption of the PVP-assisted prepared sample AMCS-2-P1 reached 4.48 mmol/g and 2.95 mmol/g at 0 °C and 25 °C respectively, which is 0.72 mmol/g and 0.25 mmol/g higher than that of AMCS-2. The carbon microspheres have high CO2 dynamic adsorption capacity, excellent selective adsorption, and good cyclic stability. Highlights: Monodisperse highly N-rich carbon microspheres were prepared by a one-step hydrothermal method. The microspheres have a good monodisperse, improved microstructure, and high N content. The microspheres have high CO2 adsorption capacity, good selective adsorption, and cycling stability. [ABSTRACT FROM AUTHOR]