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Current industrial propane dehydrogenation (PDH) processes predominantly use either toxic Cr‐based or expensive Pt‐based catalysts, necessitating urgent exploration for alternatives. Herein, we present Zn2SiO4, an easily prepared, cost‐effective material, as a highly efficient and stable catalyst for PDH. Uniquely, Zn2SiO4 nanocrystals do not require dispersion on support materials, commonly needed for catalytic active oxide clusters, but function as a self‐supporting catalyst instead. During the reaction's induction period, surface Zn species on the Zn2SiO4 crystal reduce to coordinately unsaturated ZnOx single sites, serving as highly active catalytic centers. The Zn2SiO4 catalyst demonstrates a stable performance over 200 hours of PDH operation at 550 °C. We further find that introducing a minuscule amount of CO2 into the propane feed significantly extends the catalyst lifespan to over 2000 hours. This enhancement arises from the special role of CO2 in facilitating the removal of strongly adsorbed H*, preventing the complete reduction of ZnOx. After prolonged reaction, the activity of Zn2SiO4 can be fully restored by etching the surface layer to expose fresh Zn species, available throughout the crystals. The combination of CO2introduction and catalytic site regeneration strategies is expected to enable a year‐long PDH operation using a single batch of Zn2SiO4 catalyst. [ABSTRACT FROM AUTHOR]

The Qinghai-Tibet Plateau (QTP), the highest and largest plateau in the world, plays a vital role in maintaining the balance of the global ecosystem and China's ecological barriers. The QTP ecosystems are facing serious challenges under the scenario of global climate change. Epiphytic plant diversity is one of the most significant contributors to forest diversity. Epiphytic bryophytes play an important role in forest ecosystem functioning. However, previous studies of epiphytic bryophyte diversity have rarely considered both phorophyte diversity and their ecological networks, factors that are crucial for revealing the ecological processes of community assembly and the mechanisms of biodiversity maintenance and ecosystem stability. We investigated the diversity of epiphytic bryophytes and their host trees in 18 forest sites in the southeastern QTP and analyzed the characteristics of their ecological network. A total of 57 epiphytic bryophyte species in 35 genera and 24 families and 72 individuals of host trees belonging to 14 genera and 10 families were recorded. Epiphytic bryophyte species on Picea, Abies, and Sorbus accounted for 77% of all species. The ecological network structure of epiphytic bryophytes-phorophytes exhibited low connectance and nestedness and a low degree of specialization. The cover of epiphytic bryophytes was significant positively correlated with host tree size (diameter at breast height) and not significantly correlated with bark roughness. Both tree size and bark roughness were weakly positively correlated with epiphytic bryophyte richness. The study results showed that increasing tree diversity is essential for the maintenance of the epiphytic bryophyte diversity in forests of the QTP. Biodiversity conservation of epiphytic bryophytes is consistent with conservation of their host trees.

The persistent issues of dendrite growth and side reactions have been major obstacles hampering practical applications of aqueous zinc-ion batteries (AZBs). Herein, a porous phenolic resin (PPR) artificial protective layer integrated hydrophobic framework with regular channels is constructed on Zn foil (PPR@Zn) to stabilize the Zn anode. Experimental and theoretical calculations demonstrate that the PPR@Zn layer is endowed with the following functions: (i) Zn2+ dedicated channels of PPR provide uniform diffusion pathways for Zn2+. The high ion conductivity (7.7 mS cm−1) and Zn2+ transference number (0.86) prevent localized over-deposition of Zn and improve the reaction kinetics. (ii) The affinity of PPR with Zn2+ decreases the desolvation barrier of [Zn(6H2O)]2+ and promotes rapid and uniform Zn deposition. (iii) The repulsion of H2O molecules and SO42− anions inhibits the corrosion and side reaction. (iv) Uniform space electric fields on the anode surface mitigate the "tip effect". These synergistic effects lead to dendrite-free Zn deposition. As a result, symmetrical cells assembled with PPR@Zn demonstrate an ultra-long cycle life of 4200 h. For practical applications, pairing with an MnO2 cathode, the full cells also achieved excellent cycling stability and rate performance. This work presents a promising strategy for designing corrosion-resistant, high-stability, and reversible metal anodes. [ABSTRACT FROM AUTHOR]

The construction of efficient and durable electrocatalysts with highly dispersed metal clusters and hydrophilic surface for alkaline hydrogen evolution reaction (HER) remains a great challenge. Herein, we prepared hydrophilic nanocomposites of Ru clusters (∼ 1.30 nm) anchored on Na+, K+-decorated porous carbon (Ru/Na+, K+-PC) through hydrothermal method and subsequent annealing treatment at 500 °C. The Ru/Na+, K+-PC exhibits ultralow overpotential of 7 mV at 10 mA·cm−2, mass activity of 15.7 A·mgRu−1 at 100 mV, and long-term durability of 20,000 cycles potential cycling and 200 h chronopotentiometric measurement with a negligible decrease in activity, much superior to benchmarked commercial Pt/C. Density functional theory based calculations show that the energy barrier of H-OH bond breaking is efficiently reduced due to the presence of Na and K ions, thus favoring the Volmer step. Furthermore, the Ru/Na+, K+-PC effectively employs solar energy for obtaining H2 in both alkaline water and seawater electrolyzer. This finding provides a new strategy to construct high-performance and cost-effective alkaline HER electrocatalyst. [ABSTRACT FROM AUTHOR]

Recently, the development of composite materials composed of magnetic materials and MXene has attracted significant attention. However, the thickness and microwave absorption performance of the composite is still barely satisfactory. In this work, the C-N@NiFe2O4@MXene/Ni nanocomposites were successfully synthesized in situ by hydrothermal and calcination methods. Benefiting from the introduction of the carbon-nitrogen(C-N) network structure, the overall dielectric properties are improved effectively, consequently reducing the thickness of the composite while maintaining excellent absorption performance. As a result, the minimum reflection loss of C-N@NiFe2O4@MXene/Ni can reach −50.51 dB at 17.3 GHz at an ultralow thickness of 1.5 mm, with an effective absorption bandwidth of 4.95 GHz (13.02–18 GHz). This research provides a novel strategy for materials to maintain good absorption performance at an ultralow thickness level. [ABSTRACT FROM AUTHOR]

It is challenging and desirable to construct Pt-based nanocomposites with oxygen storage function as efficient oxygen reduction reaction (ORR) catalysts for practical proton exchange membrane fuel cells (PEMFCs). Herein, we achieve novel porous nanocomposites of PtCu3 nanoalloys-embedded in the PWOx matrix (PtCu3@PWOx), which has an oxygen container feature. The PtCu3@PWOx/C exhibits an ultrahigh mass activity (MA) of 3.94 A·mgPt−1 for ORR, which is 26.3 times as high as the commercial Pt/C and the highest value ever reported for PtCu-based binary system. Theoretical calculations reveal that the compressive strain and d-band center downshift of Pt intrinsically contribute to the excellent ORR performance. In H2-air PEMFCs at room temperature, furthermore, the PtCu3@PWOx/C delivers a high power density (218.6 mW·cm−2), much superior to commercial Pt/C (131.6 mW·cm−2). In H2-O2 PEMFCs, PtCu3@PWOx/C outputs a maximum power density of 420.1 mW·cm−2. This work provides an effective idea for designing oxygen-storing ORR catalysts used for practical room-temperature H2-air fuel cells. [ABSTRACT FROM AUTHOR]

Here, we report a gold-furnished mesh as the current collector for Zn electrodeposition, which is used as the anode in aqueous zinc-ion batteries. The anode exhibits excellent cycling performance without obvious dendrite growth, and the full cell shows an outstanding specific capacity and long-term durability, surpassing those of bare Zn.

The traditional methods for creating oxygen vacancies in materials present several challenges and limitations, such as high preparation temperatures, limited oxygen vacancy generation, and morphological destruction, which hinder the application of transition metal oxides in the field of zinc-air batteries (ZABs). In order to address these limitations, we have introduced a pioneering lithium reduction strategy for generating oxygen vacancies in δ-MnO 2 @MXene composite materials. This strategy stands out for its simplicity of implementation, applicability at room temperature, and preservation of the material's structural integrity. This research demonstrates that aqueous Ov-MnO 2 @MXene-5, with introduced oxygen vacancies, exhibits an outstanding oxygen reduction reaction (ORR) activity with an ORR half-wave potential reaching 0.787 V. DFT calculations have demonstrated that the enhanced activity could be attributed to adjustments in the electronic structure and alterations in adsorption bond lengths. These adjustments result from the introduction of oxygen vacancies, which in turn promote electron transport and catalytic activity. In the context of zinc-air batteries, cells with Ov-MnO 2 @MXene-5 as the air cathode exhibit outstanding performance, featuring a significantly improved maximum power density (198.3 mW cm -2 ) and long-term cycling stability. Through the innovative strategy of introducing oxygen vacancies, this study has successfully enhanced the electrochemical catalytic performance of MnO 2 , overcoming the limitations associated with traditional methods for creating oxygen vacancies. Consequently, this research opens up new avenues and directions for nonprecious metal catalyst application in ZABs.

A transition metal phosphide is an excellent candidate for supercapacitors due to its superior electrical conductivity and high theoretical capacity. In addition, compared with traditional 3D nano-materials, 2D nanosheets possess a greater specific surface area and shorter electron transport distance. In this study, a reasonable approach is proposed for the synthesis of ZIF-67 nanosheets on nickel foam with subsequent phosphorization by chemical vapor deposition (CVD) to obtain flake-like CoP combined with Ni2P (NCP/NF), in which nickel foam serves as the current collector as well as the resource of Ni to form Ni2P. Benefiting from the nanosheet array of CoP, the NCP/NF can improve the capacity of Ni2P from 0.57 C cm-2 to 1.43 C cm-2 at 1 mA cm-2. Furthermore, the NPC/NF/reduced graphene oxide (RGO) asymmetric supercapacitor (ASC) shows an energy density of 26.9 μW h cm-2 at a power density of 0.896 mW cm-2, and excellent cycling performance with a capacity retention of 93.75% after 5000 cycles at 10 mA cm-2.