Catalyst design plays vital roles in structurally relevant reactions. Revealing the catalyst structure and chemistry in the reactive environment at the atomic scale is imperative for the rational design of catalysts as well as the investigation of reaction mechanisms, while in situ characterization at the atomic scale at high temperature is still a great challenge. Here, tracking intermetallic Co 7 W 6 nanocrystals with a defined structure and a high melting point by environmental aberration-corrected transmission electron microscopy in combination with in situ synchrotron X-ray absorption spectroscopy, we directly present the structural and chemical stability of the Co 7 W 6 nanocrystals in methane, carbon monoxide, and hydrogen at temperatures of 700−1100 °C. The evidence is in situ and in real time with both atomic scaled resolution and collective information. The results are helpful in revealing the mechanism of structural-specified synthesis of single-walled carbon nanotubes. This research offers an example of systematic investigation at the atomic scale on catalysts under reactive conditions. Such catalysts presenting high structural stability may also find applications in other structure-specific synthesis.

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Deep‐sea environments are the largest ecosystem of the global biosphere and constitute a crucial role in global biogeochemical cycles. We integrated biogeochemical and molecular ecological approaches to investigate microbial activity and diversity, with the goal of elucidating pathways and regulations of methane cycling and low molecular weight (LMW) compounds metabolism in different deep‐sea sediments of the South China Sea. We found that methanogenesis, anaerobic oxidation of methane, and sulfate reduction occurred concurrently with low rates in surface sediments of the Haima area (~ 50 cm push cores) and in subsurface sediments of the Shenhu area (~ 8 m piston core). In the presence of sulfate, methanogenesis was fueled by methylotrophic substrates, in agreement with thermodynamic calculations as well as the detection of the methylotrophic methanogenic genus Methanococcoides. Higher oxidation rates of LMW compounds than methanogenesis rates, suggested acetate, and to a lesser extent, methanol and methylamine, were predominantly utilized as an energy source by nonmethanogenic microorganisms (e.g., sulfate‐reducing bacteria). Diverse methanotrophic archaea (e.g., ANME‐1a/b and ANME‐2a/b) and sulfate‐reducing bacteria (e.g., Desulfarculaceae and Desulfobacteraceae) were observed and the abundance of mcrA and dsrA genes varied over depth and between sites. Dominant archaeal groups, such as Bathyarchaeota, Thermoplasmatale, Woesearchaeota, Lokiarchaeota, were consistently detected at both areas. Multivariate statistical analysis demonstrated sulfate was the most relevant environmental variable that correlated with the archaeal community composition. These results suggested that the presence of sulfate controlled methane cycling and LMW carbon metabolism pathways, and also affected the composition of the microbial community.

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Visible-light-induced living radical polymerization of acrylates (MA, nBA, tBA), acrylamides (DMA, AMO), and vinyl acetate (VAc) at ambient temperature mediated by (salen)Co(II)/TPO was described. Effects of light intensity, feeding ratio of monomer and equivalent of TPO for the polymerization of MA were investigated. Well-defined homopolymers and block polymers with predetermined molecular weight and narrow polydispersity were obtained under mild conditions. The mechanism of the polymerization was proposed based on polymerization behavior and polymer structure analysis. The (salen)Co(II)/TPO system was suitable for both conjugated and unconjugated monomers under mild conditions.