Nanoprecipitation is a routine method to decrease the thermal conductivity for advancing thermoelectric performance. However, the coarsening/Ostwald ripening of precipitates under temperature gradients in long-duration service deteriorates the efficacy of...

Superconductor-insulator transition (SIT) in one-dimensional (1D) nanowires attracts great attention in the past decade and remains an open question since contrasting results were reported in nanowires with different morphologies (i.e., granular, polycrystalline, or amorphous) or environments. Nb2PdS5 is a recently discovered low-dimensional superconductor with typical quasi-1D chain structure. By decreasing the wire diameter in the range of 100-300 nm, we observed a clear SIT with a 1D transport character driven by both the cross-sectional area and external magnetic field. We also found that the upper critical magnetic field (Hc2) decreases with the reduction of nanowire cross-sectional area. The temperature dependence of the resistance below Tc can be described by the thermally activated phase slip (TAPS) theory without any signature of quantum phase slips (QPS). These findings demonstrated that the enhanced Coulomb interactions with the shrinkage of the wire diameter competes with the interchain Josephson-like coupling may play a crucial role on the SIT in quasi-1D system.

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Medium‐entropy alloy aerogels (MEAAs) with the advantages of both multimetallic alloys and aerogels are promising new materials in catalytic applications. However, limited by the immiscible behavior of different metals, achieving single‐phase MEAAs is still a grand challenge. Herein, a general strategy for preparing ultralight 3D porous MEAAs with the lowest density of 39.3 mg cm−3 among the metal materials is reported, through combining auto‐combustion and subsequent low‐temperature reduction procedures. The homogenous mixing of precursors at the ionic level makes the short‐range diffusion of metal atoms possible to drive the formation of single‐phase MEAAs. As a proof of concept in catalysis, as‐synthesized Ni50Co15Fe30Cu5 MEAAs exhibit a high mass activity of 1.62 A mg−1 and specific activity of 132.24 mA cm−2 toward methanol oxidation reactions, much higher than those of the low‐entropy counterparts. In situ Fourier transform infrared and NMR spectroscopies reveal that MEAAs can enable highly selective conversion of methanol to formate. Most importantly, a methanol‐oxidation‐assisted MEAAs‐based water electrolyzer can achieve a low cell voltage of 1.476 V at 10 mA cm−2 for making value‐added formate at the anode and H2 at the cathode, 173 mV lower than that of traditional alkaline water electrolyzers.

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The heterogenization of homogeneous metal complex catalysts has attracted great attention. The encapsulation of metal complexes into nanochannels of mesoporous materials is achieved by coating metal oxides at/near the pore entrance by diffusion-limited atomic layer deposition (ALD) to produce a hollow plug. The pore size of the hollow plug is precisely controlled on the sub-nanometer scale by the number of ALD cycles to fit various metal complexes with different molecular sizes. Typically, Co or Ti complexes are successfully encapsulated into the nanochannels of SBA-15, SBA-16, and MCM-41. The encapsulated Co and Ti catalysts show excellent catalytic activity and reusability in the hydrolytic kinetic resolution of epoxides and asymmetric cyanosilylation of carbonyl compounds, respectively. This ALD-assisted encapsulation method can be extended to the encapsulation of other homogeneous catalysts into different mesoporous materials for various heterogeneous reactions.

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