The genesis of large igneous provinces (LIP) is controlled by multiple factors including anomalous mantle temperatures, the presence of fusible fertile components and volatiles in the mantle source, and the extent of decompression. The lack of a comprehensive examination of all these factors in one specific LIP makes the mantle plume model debatable. Here, we report estimates of the water content in picrites from the Emeishan LIP in southwestern China. Although these picrites display an island arc-like H2O content (up to 3.4 by weight percent), the trace element characteristics do not support a subduction zone setting but point to a hydrous reservoir in the deep mantle. Combining with previous studies, we propose that hydrous and hot plumes occasionally appeared in the Phanerozoic era to produce continental LIPs (e.g., Tarim, Siberian Trap, Karoo). The wide sampling of hydrous reservoirs in the deep mantle by mantle plumes thus indicates that the Earth’s interior is largely hydrated.

Although Fenton or Fenton-like reactions have been widely used in the environment, biology,life science,and other fields,t he sharp decrease in their activity under macroneutral conditions is still al arge problem. This study reports aM oS 2 cocatalytic heterogeneous Fenton (CoFe 2 O 4 /MoS 2 )s ystem capable of sustainably degrading organic pollutants,s uch as phenol, in am acroneutral buffer solution. An acidic microenvironment in the slipping plane of CoFe 2 O 4 is successfully constructed by chemically bonding with MoS 2 .T his microenvironment is not affected by the surrounding pH, which ensures the stable circulation of Fe 3+ /Fe 2+ on the surface of CoFe 2 O 4 /MoS 2 under neutral or even alkaline conditions. Additionally,C oFe 2 O 4 /MoS 2 always exposes "fresh" active sites for the decomposition of H 2 O 2 and the generation of 1 O 2 , effectively inhibiting the production of iron sludge and enhancing the remediation of organic pollutants,even in actual wastewater.T his work not only experimentally verifies the existence of an acidic microenvironment on the surface of heterogeneous catalysts for the first time,but also eliminates the pH limitation of the Fenton reaction for pollutant remediation, therebye xpanding the applicability of Fenton technology.

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The universal limit on the pH conditions is disturbing peroxymonosulfate (PMS)-triggered high-valent iron-oxo systems in environmental applications. Here, we propose for the first time the construction of a neutral microenvironment on the surface of ZnÀ Fe layered double hydroxide (ZnFe-LDH) by using the amphoteric properties of zinc hydroxide, which continuously generates �Fe IV =O over a wide pH range of 3.0-11.0 in activating PMS. The �Zn(OH) 2 moiety offers a neutral microenvironment at the phase interface, which mitigates the self-decomposition of �Fe IV =O by protons and the hydrolysis reaction of iron by hydroxyl groups, which is supported by the Mossbauer spectra, density functional theory calculations and designed experiments. Consequently, ZnFe-LDH/PMS can satisfy the stability in long-term experiments, selectivity under conditions with high salinity or natural organic matter and efficient treatment of actual wastewater.

Advanced oxidation processes (AOPs) based on peroxymonosulfate (PMS) have been effective techniques for wastewater treatment. However, the recovery of powder catalysts and their granulation are limiting the application of heterogeneous AOPs technology. To tackle these issues, recoverable graphene oxide-based three-dimensional (3D) cobalt−nickel bimetallic sponges (SCNGs) were synthesized via a simple dipping process. Thermogravimetric analysis confirmed that the bimetal content of SCNGs was only 7.7%. The SCNGs/PMS system was proved to be greatly effective to treat various organic pollutants, achieving over 71% and 94% of degradation efficiency for phenolic substances (phenol and 4-chlorophenol) and antibiotics (tetracycline and sulfadiazine) in 5 min over a wide initial pH range of 4.0−9.0, respectively. The correlative quenching experiments and electronic paramagnetic resonance tests verified the existence of multiple reactive oxygen species ( 1 O 2 , SO 4•− , HO • , and O 2 •− ), whereas 1 O 2 that originated from PMS self-decomposition and O 2•− conversion played the most important role in the degradation processes. Overall, this study provides a prospect for the industrial application of 3D bimetallic materials based on PMS activation in wastewater treatment.

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It is important to develop highly active and stable catalysts for high temperature reactions, such as dry reforming of methane. Here we show a La(NiCo)OΔ (LNCO) submonolayer catalyst (SMLC) stabilized by the surface lattice of a perovskite LaCrO3 support and demonstrate a Ni-Co synergistic effect. The submonolayer/support type catalyst was prepared by in-situ hydrogen reduction of a LaNi0.05Co0.05Cr0.9O3 precursor synthesized by a sol-gel method. The LNCO-SMLC is highly active and very stable during a 100 h on stream test at 750 °C under the reaction conditions of dry reforming of methane. The catalyst also shows good anti-coking ability. We found that the synergistic effect between Ni and Co atoms in LNCO-SMLC remarkably improved the thermostability of the catalyst. This work provides a useful concept for designing atomically dispersed catalysts with high thermostability.

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