Single-atom catalysts (SACs) have demonstrated superior catalytic performance in numerous heterogeneous reactions. However, producing thermally stable SACs, especially in a simple and scalable way, remains a formidable challenge. Here, we report the synthesis of Ru SACs from commercial RuO 2 powders by physical mixing of sub-micron RuO 2 aggregates with a MgAl 1.2 Fe 0.8 O 4 spinel. Atomically dispersed Ru is confirmed by aberration-corrected scanning transmission electron microscopy and X-ray absorption spectroscopy. Detailed studies reveal that the dispersion process does not arise from a gas atom trapping mechanism, but rather from anti-Ostwald ripening promoted by a strong covalent metalsupport interaction. This synthetic strategy is simple and amenable to the large-scale manufacture of thermally stable SACs for industrial applications.

A Ni-catalyzed reductive approach to the cross-coupling of two unactivated alkyl halides has been successfully developed. The reaction works efficiently for primary and secondary halides, with at least one being bromide. The mild reaction conditions allow for excellent functional group tolerance and provide the C(sp(3))-C(sp(3)) coupling products in moderate to excellent yields.

Single‐atom catalysts have attracted much interest recently because of their excellent stability, high catalytic activity, and remarkable atom efficiency. Inspired by the recent experimental discovery of a highly efficient single‐atom catalyst Pd1/γ‐Al2O3, we conducted a comprehensive DFT study on geometries, stabilities and CO oxidation catalytic activities of M1/γ‐Al2O3 (M=Pd, Fe, Co, and Ni) by using slab‐model. One of the most important results here is that Ni1/Al2O3 catalyst exhibits higher activity in CO oxidation than Pd1/Al2O3. The CO oxidation occurs through the Mars van Krevelen mechanism, the rate‐determining step of which is the generation of CO2 from CO through abstraction of surface oxygen. The projected density of states (PDOS) of 2p orbitals of the surface O, the structure of CO‐adsorbed surface, charge polarization of CO and charge transfer from CO to surface are important factors for these catalysts. Although the binding energies of Fe and Co with Al2O3 are very large, those of Pd and Ni are small, indicating that the neighboring O atom is not strongly bound to Pd and Ni, which leads to an enhancement of the reactivity of the O atom toward CO. The metal oxidation state is suggested to be one of the crucial factors for the observed catalytic activity.

Endohedral metallofullerenes (EMFs) are novel derivatives of fullerenes that can encapsulate metal atoms or clusters in their inner space.[1] Owing to their extraordinary properties attributed to significant electron transfer from the metal atoms to the fullerene cage, [2] EMFs have attracted wide interests since the discovery of fullerenes.[3] For instance, lanthanide metallofullerenes have been suggested for use as encapsulated contrasting agents for magnetic resonance imaging. [4] In EMFs, the internal metal atoms always donate electrons to the fullerene cage and carry considerable positive charges. It is interesting and highly significant to investigate the possible formation of metal-metal bonds between these metal atoms in EMFs. [5][6][7] From a theoretical point of view, the study of metal-metal bonds in EMFs gives an in-depth perspective of the metal-metal interaction and provides an approach for further experimental and theoretical explorations of metal-metal interactions. [6,8] On the other hand, in contrast to the fact that several kinds of metal-metal bonds have been studied, in other fields, [9] up to now only rare examples of metal-metal bonds are reported in fullerene chemistry.[7] Furthermore, the presence of metal-metal bonds produces unique structures and fascinating electronic properties of EMFs, which may extend their promising applications in electronics, magnetism, and photovoltaics. [7,10] Most importantly, previous studies have indicated that the encapsulated metal atoms can move around in fullerene cage at room temperature.[11] This dynamic motion makes it possible to design these EMFs as functional molecular devices with new magnetic and electronic properties. [12] It is also an interesting question whether other novel dynamic motion of the encapsulated metals exists in fullerene cage.Lots of efforts have been devoted to metal-metal bonds in EMFs during the past decades, but only a few single metal-metal bonds have been found and confirmed. [6][7][8][13][14][15] In fact, Stevenson et al. suggested the presence of a Sc À Sc bond between the shortest Sc À Sc distance with a newly experimentally determined structure of Sc 4 O 2 @C 80 .[14] Two kinds of metal-metal bonds have been found between Y atoms so far: one two-electron bond in the Y 2 @C 82 , [7] and another long single-electron bond in Y 2 @C 79 N.[15] In addition, a single-electron bond between Tb atoms was also proposed in Tb 2 @C 79 N.[15]Herein we present a thorough investigation on a newly isolated dimetallofullerene Lu 2 @C 76 , [16] and find that the two lutetium atoms prefer to bind together to form an unprecedented single metal-metal bond, in a formal valence state of [Lu 2 ] 4 + @C 76 4À by means of combined quantum chemical and statistical thermodynamic approaches. More interestingly, it is shown that the Lu atoms can hop rapidly between six equivalent configurations in the fullerene cage at room temperature, giving rise to a trajectory as a tetrahedron in C 76 (T d ). Systematic calculations on the di-, tetra-, he...