Lithium−sulfur (Li−S) batteries suffer from multiple complex and often interwoven issues, such as the low electronic conductivity of sulfur and Li 2 S/Li 2 S 2 , shuttle effect, and sluggish electrochemical kinetics of lithium polysulfides (LiPSs). Guided by theoretical calculations, a multifunctional catalyst of isolated single-atom nickel in an optimal Ni−N 5 active moiety incorporated in hollow nitrogen-doped porous carbon (Ni−N 5 /HNPC) is constructed and acts as an ideal host for a sulfur cathode. The host improved electrical conductivity, enhanced physical-chemical dual restricting capability toward LiPSs, and, more importantly, boosted the redox reaction kinetics by the Ni−N 5 active moiety. Therefore, the Ni−N 5 /HNPC/S cathode exhibits superior rate performance, long-term cycling stability, and good areal capacity at high sulfur loading. This work highlights the important role of the coordination number of active centers in single-atom catalysts and provides a strategy to design a hollow nanoarchitecture with single-atom active sites for high-performance Li−S batteries.

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A facile strategy to prepare sintering- and leaching-resistant core-shell nanocatalysts is reported. ZIF-derived porous carbon supported Pd nanoparticles are coated with a mesoporous silica shell, preventing Pd nanoparticles from sintering at high temperature and leaching in a catalytic process. This nanocatalyst exhibits excellent catalytic activity and recyclability for the oxidation of benzyl alcohol.

ZSM-5 by EtOH, possessing an ultra-high Brønsted/Lewis acidity ratio, has a long lifetime and suppresses coke deposit during n-hexane cracking.