Metal atoms dispersed on the oxide supports constitute a large category of single-atom catalysts. In this review, oxide supported single-atom catalysts are discussed about their synthetic procedures, characterizations, and reaction mechanism in thermocatalysis, such as water–gas shift reaction, selective oxidation/hydrogenation, and coupling reactions. Some typical oxide materials, including ferric oxide, cerium oxide, titanium dioxide, aluminum oxide, and so on, are intentionally mentioned for the unique roles as supports in anchoring metal atoms and taking part in the catalytic reactions. The interactions between metal atoms and oxide supports are summarized to give a picture on how to stabilize the atomic metal centers, and rationally tune the geometric structures and electronic states of single atoms. Furthermore, several directions in fabricating single-atom catalysts with improved performance are proposed on the basis of state-of-the-art understanding in metal-oxide interactions.

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The two North Atlantic eel species, the European eel (Anguilla anguilla) and the American eel (Anguilla rostrata), spawn in partial sympatry in the Sargasso Sea, providing ample opportunity to interbreed. In this study, we used a RAD (Restriction site Associated DNA) sequencing approach to identify species-specific diagnostic single-nucleotide polymorphisms (SNPs) and design a low-density array that combined with screening of a diagnostic mitochondrial DNA marker. Eels from Iceland (N ¼ 159) and from the neighboring Faroe Islands (N ¼ 29) were genotyped, along with 94 larvae (49 European and 45 American eel) collected in the Sargasso Sea. Our SNP survey showed that the majority of Icelandic eels are pure European eels but there is also an important contribution of individuals of admixed ancestry (10.7%). Although most of the hybrids were identified as F1 hybrids from European eel female  American eel male crosses, backcrosses were also detected, including a first-generation backcross (F1 hybrid  pure European eel) and three individuals identified as second-generation backcrosses originating from American eel  F1 hybrid backcrosses interbreeding with pure European eels. In comparison, no hybrids were observed in the Faroe Islands, the closest bodies of land to Iceland. It is possible that hybrids show an intermediate migratory behaviour between the two parental species that ultimately brings hybrid larvae to the shores of Iceland, situated roughly halfway between the Sargasso Sea and Europe. Only two hybrids were observed among Sargasso Sea larvae, both backcrosses, but no F1 hybrids, that points to temporal variation in the occurrence of hybridization.

We report an improved procedure for the determination of the platinum-group elements (PGE) and Re, and Os isotopes from a single sample aliquot by isotope dilution (ID) using inductively coupled plasma-mass spectrometry (ICP-MS) and negative thermal ionisation mass spectrometry (N-TIMS), respectively. A two-stage column method was used to purify PGE-Re from their sample matrix and interfering elements (e.g., Mo, Zr and Hf) after Os had been separated by CCl 4 solvent extraction. The first column separation step used cation exchange resin (AG50W-X8) to concentrate PGE-Re and some potential interfering elements (e.g., Mo, Zr and Hf). In the second step, N-benzoyl-N-phenylhydroxylamine (BPHA) extraction resin was used to separate PGE-Re from the remaining interfering elements, which all remained strongly absorbed to the resin. The method was used to determine the PGE and rhenium, and Os isotope ratios in a range of geochemical reference materials (TDB-1, WGB-1, BHVO-2 and UB-N). The obtained results agree well with those previously published. This new method enables PGE-Re abundances and Os isotopic ratios to be determined on the same sample digestion, and circumvents the problems created by sample heterogeneity when comparing PGE and Re-Os isotope data.

The palladium-catalyzed Heck reaction is aw ellknown, Nobel Prizew inning transformation for producing alkenes.U nlike the alkenyl and aryl variants of the Heck reaction, the alkyl-Heck reaction is still underdeveloped owing to the competitive side reactions of alkyl-palladium species. Herein, we describe the development of ad eaminative alkyl-Heck-type reaction that proceeds through C À Nb ond activation by visible-light photoredoxcatalysis.Avariety of aliphatic primary amines were found to be efficient starting materials for this new process,affording the corresponding alkene products in good yields under mild reaction conditions.M oreover,t his strategy was successfully applied to deaminative carbonylative alkyl-Heck-type reactions.

Developing homogeneous catalysts that convert CS and COS pollutants into environmentally benign products is important for both fundamental catalytic research and applied environmental science. Here we report a series of air-stable dimeric Pd complexes that mediate the facile hydrolytic cleavage of both CS carbon-sulfur bonds at 25 °C to produce CO and trimeric Pd complexes. Oxidation of the trimeric complexes with HNO regenerates the dimeric starting complexes with the release of SO and NO. Isotopic labelling confirms that the carbon and oxygen atoms of CO originate from CS and HO, respectively, and reaction intermediates were observed by gas-phase and electrospray ionization mass spectrometry, as well as by Fourier transform infrared spectroscopy. We also propose a plausible mechanistic scenario based on the experimentally observed intermediates. The mechanism involves intramolecular attack by a nucleophilic Pd-OH moiety on the carbon atom of coordinated µ-OCS, which on deprotonation cleaves one C-S bond and simultaneously forms a C-O bond. Coupled C-S cleavage and CO release to yield [(bpy)Pd(µ-S)](NO) (bpy, 2,2'-bipyridine) provides the thermodynamic driving force for the reaction.

The advances on transition-metal catalysed asymmetric couplings with light intervention in recent years was summarized in this review. In order to better meet the needs of modern chemistry, further research outlook was also proposed.

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