Rational design of noble metal catalysts with the potential to leverage efficiency is vital for industrial applications. Such an ultimate atom-utilization efficiency can be achieved when all noble metal atoms exclusively contribute to catalysis. Here, we demonstrate the fabrication of wafer-size amorphous PtSex film on SiO2 substate via a low-temperature amorphizing strategy, which offers single-atom-layer Pt catalysts with high atom-utilization efficiency (~26 wt%). This amorphous PtSex (1.2

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Solid‐state cooling exploits the thermal response of caloric materials when subjected to external physical fields and represents a promising alternative to conventional refrigeration technologies. However, existing caloric materials are often limited by relatively small caloric response and hysteresis issues rooted in first‐order structural transitions. Here, colossal and reversible elastocaloric effects near room temperature in superelastic graphene architectures are predicted by thermodynamic analysis and atomistic calculations. The estimated adiabatic temperature change can reach a value of 155 K under a compressive stress of 0.7 GPa in a wide temperature range of around 300 K, yielding outstanding elastocaloric strength and efficiency. More unique is that both cooling and warming can be realized in the materials by applying tensile and compressive strains to host conventional and inverse elastocaloric effects, respectively, with almost no fatigue behavior and hysteresis effect. Such unprecedented elastocaloric performance results from a strain‐induced large change in configurational entropy in the graphene architectures. These effects are potentially extendable to other superelastic nanomaterials and hence suggest new material settings for developing high‐performance solid‐state refrigerants.

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By choosing suitable ligand-directed gold catalysts, two types of gold-containing all-carbon 1,4-dipoles could be generated selectively from the gold(I)-catalyzed cycloisomerizations of allenyl ketones bearing a cyclopropyl moiety, which undergo [4 + 3] cycloadditions with nitrones to produce two regiomers of furan-condensed N,O-seven-membered rings in moderate to excellent yields highly selectively.I ntermolecular cycloaddition represents a powerful tool to create a myriad of functionalized carbocyclic and heterocyclic frameworks in a highly regio-and stereocontrolled fashion. 1 While traditional protocols by applying stable conjugated 1,3-dipoles to react with unsaturated bonds to produce cyclic motifs are well documented, 2 studies on utilizing nonclassical all-carbon 1,4-dipoles, a class of highly reactive variants without a fully conjugated system, 3 for cycloaddition reactions remain a critical challenge and are of high value in organic chemistry.Benefiting from the development of the transition-metal catalysis in organic synthesis, 4 a few approaches have been established to enter the polarized four-carbon units, binding a relatively strong carbon−metal bond via elaborate design of substrates. 5 For example, in 2007, an elegant work involving the generation of 1,4-zwitterionic dipoles with a π-allylpalladium moiety from a palladium(0)-catalyzed oxidative addition into the γ-methylidene-δ-valerolactones and decarboxylation process was first disclosed by Hayashi 6 and co-workers (Scheme 1, eq 1). Later, vinyl benzoxazinanone derivatives have also been successfully used as valuable precursors of an aromatic ring containing 1,4-dipoles undergoing a similar decarboxylation process. 7 The homogeneous gold catalysis has emerged as a continuously growing field of investigation. 8 Owing to the exceptional π-acidity of cationic gold(I) complexes to activate unsaturated carbon−carbon bonds, Zhang's group 9 developed the first gold(I)-catalyzed cycloisomerization of 1-(1-alkynyl)cyclopropyl ketones toward

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