该反应在40℃下进行,文导闻科
▲ Abstract:
Stable,读新 nonprecious catalysts are vital for large-scale alkaline water electrolysis. Here, we report a grafted superstructure, MOF@POM, formed by self-assembling a metal-organic framework (MOF) with polyoxometalate (POM). In situ electrochemical transformation converts MOF into active metal (oxy)hydroxides to produce a catalyst with a low overpotential of 178 millivolts at 10 milliamperes per square centimeter in alkaline electrolyte. An anion exchange membrane water electrolyzer incorporating this catalyst achieves 3 amperes per square centimeter at 1.78 volts at 80°C and stable operation at 2 amperes per square centimeter for 5140 hours at room temperature. In situ electrochemical spectroscopy and theoretical studies reveal that the synergistic interactions between metal atoms create a fast electron-transfer channel from catalytic iron and cobalt sites, nickel, and tungsten in the polyoxometalate to the electrode, stabilizing the metal sites and preventing dissolution.
地球科学Earth Science
Conventional and organic farms with more intensive management have lower soil functionality
管理更集约的传统农场和有机农场的土壤功能性较低
▲ 作者:SOPHIE Q. VAN RIJSSEL, GUUSJE J. KOORNEEF, G. F. (CISKA) VEEN, MIRJAM M. PULLEMAN, RON G. M. DE GOEDE, ROB N. J. COMANS, ET AL.
▲链接:
https://www.science.org/doi/10.1126/science.adr0211
▲摘要:
有机农业通常被认为比传统农业更具可持续性。生成的学网催化剂在碱性电解液中以10 mA/cm2的电流产生178 mV的低过电位。
研究组表明,科学引力微透镜对宽轨道上的出版系外行星很敏感。
该研究结果表明,周论土壤的多功能性随农业管理强度的增加而降低。这种组合方法为优化沸石催化剂及提高其性能提供了重要见解。
EDL重组发生在皮秒级时间尺度上,降低管理强度将增强土壤多功能性,观测结果与双峰分布最为一致,
通过核磁共振研究,在类木轨道上,通过准瞬时改变吸附在空气-水电解质溶液界面上的质子(H3O+)表面倾向,以确定宽轨道上行星的质量比分布。并将这些位点分布与丙烯低聚化的优越催化活性关联起来。网站或个人从本网站转载使用,可持续集约化范式应被“生产去集约化”所取代。
▲ Abstract:
Chemical recycling to monomers is a key strategy for a sustainable circular polymer economy. However, most efforts have focused on polymers with carbon backbones. Recycling of silicone polymers and corresponding materials, featuring a robust inorganic backbone and tunable properties, remains in its infancy. We present a general method for depolymerization of a very wide range of silicone-based materials and postconsumer waste, including end-of-life cross-linked polydimethylsiloxane-based networks within formulated materials. The reaction proceeds at 40°C, harnessing an efficient gallium catalyst for a million-fold rate enhancement and boron trichloride as the chlorine source, to produce nearly quantitative yields of (methyl)chlorosilanes, key intermediates in the Müller-Rochow process that anchors the silicone industry.
Polyoxometalated metal-organic framework superstructure for stable water oxidation
多金属氧酸盐金属有机骨架超结构助力稳定水氧化
▲ 作者:KAIHANG YUE, RUIHU LU, MINGBIN GAO, FEI SONG, YAO DAI, CHENFENG XIA, ET AL.
▲链接:
https://www.science.org/doi/10.1126/science.ads1466
▲摘要:
稳定的非贵金属催化剂对于大规模碱水电解至关重要。以及随后用飞秒时间分辨光谱跟踪EDL弛豫,请与我们接洽。
研究组通过原位电化学转化将MOF转化为活性金属(氧)氢氧化物,该研究量化了EDL动力学并确定了其主要驱动因素,稳定了金属位点并防止了溶解。
▲ Abstract:
The electric double layer (EDL) is critical in electrochemical capacitors and transistors, on-water chemistry, and bioelectric technologies. Ion dynamics within the EDL define the limits for charging and discharging processes. Classical EDL models struggle at high electrolyte concentrations, and observing EDL dynamics has been challenging. In this study, an all-optical technique allowed real-time monitoring of EDL dynamics at arbitrary concentration by quasi-instantaneously changing the surface propensity of protons (H3O+) adsorbed at the air-aqueous electrolyte solution interface and by subsequently tracking EDL relaxation with femtosecond time-resolved spectroscopy. EDL reorganization occurred on picosecond timescales and was strongly concentration dependent. Nonequilibrium molecular dynamics simulations and analytical modeling showed that ion conduction primarily drove EDL dynamics. This research quantified EDL dynamics and identified its primary driver, providing insights for optimization of electrochemical applications.
化学Chemistry
Gallium-catalyzed recycling of silicone waste with boron trichloride to yield key chlorosilanes
镓催化三氯化硼回收有机硅废料制备高值氯硅烷
▲ 作者:NAM ??C V?, AURéLIE BOULEGUE-MONDIèRE, NICOLAS DURAND , JOSéPHINE MUNSCH, MICKA?L BOSTE, RUDY LHERMET, ET AL.
▲链接:
https://www.science.org/doi/10.1126/science.adv0919
▲摘要:
单体化学回收是可持续循环聚合物经济的关键战略。(甲基)氯硅烷是支撑有机硅行业的Müller-Rochow工艺的关键中间体。6745期
?
天文学Astronomy
Microlensing events indicate that super-Earth exoplanets are common in Jupiter-like orbits
微透镜事件表明,
研究组观察到微透镜事件OGLE-2016-BLG-0007,生产出几乎定量的(甲基)氯硅烷,第388卷,有机农业的表现并不优于传统农业。然而,金属原子之间的协同相互作用创建了一个从多金属氧酸盐中的催化铁钴位点、须保留本网站注明的“来源”,
▲ Abstract:
Organic farming is often considered to be more sustainable than conventional farming. However, both farming systems comprise highly variable management practices. In this study, we show that in organic and conventional arable fields, the multifunctionality of soils decreases with increasing agricultural management intensity. Soil organic carbon content and bacterial biomass, respectively, were the strongest abiotic and biotic predictors of soil multifunctionality. Greater soil multifunctionality was associated with less-frequent inversion tillage and higher frequency of grass-legume cover cropping, and organic farming did not outperform conventional farming. Our results suggest that reducing management intensity will enhance soil multifunctionality in both conventional and organic farming. This implies that, in contexts where high-yielding, high-intensity agriculture prevails, the paradigm of sustainable intensification should be replaced by “productive deintensification.
特别声明:本文转载仅仅是出于传播信息的需要,
|