Propane dehydrogenation (PDH) is promising for producing high value-added propylene. The discovery of a more efficient, economical, and nontoxic PDH catalyst is of great importance. Herein, we found zinc hydrides ([ZnH]+) as the highly reactive site for PDH. In situ spectroscopy and theoretical studies reveal that [ZnH]+ was transformed from zinc hydroxyl ([ZnOH]+) sites under reductive conditions. Accordingly, the formation of [ZnH]+ can be controlled by adjusting the amount of zinc hydroxyl ([ZnOH]+) species by various additives. The optimized Cu–ZnO@S-1 consists of exclusively isolated [ZnOH]+ sites, which help produce more [ZnH]+ toward optimal PDH activity. Specifically, the catalyst enables 43% propane conversion with >88% propylene selectivity, close to the thermodynamic equilibrium. This efficient PDH performance was attributed to the electron-deficient Zn in [ZnH]+ that can lower the dehydrogenation barrier, and the Cu-modified [ZnH]+ structure favors the direct PDH pathway to further promote the formation of propylene and H2.

The two-dimensional boron monolayer (borophene) stands out from the two-dimensional atomic layered materials due to its structural flexibility and tunable electronic and mechanical properties from a large number of allotropic materials. The stability of pristine borophene polymorphs could possibly be improved via hydrogenation with atomic hydrogen (referred to as borophane). However, the precise adsorption structures and the underlying mechanism are still elusive. Employing first-principles calculations, we demonstrate the optimal configurations of freestanding borophanes and the ones grown on metallic substrates. For freestanding borophenes, the energetically favored hydrogen adsorption sites are sensitive to the polymorphs and corresponding coordination numbers of boron atoms. With various metal substrates, the hydrogenation configurations of borophenes are modulated significantly, attributed to the overlap between B p z and H s orbitals. These findings provide a deep insight into the hydrogenating borophenes and facilitate the stabilization of two-dimensional boron polymorphs by engineering hydrogen adsorption sites and concentrations.

Propane direct dehydrogenation (PDH) is an attractive technology for propylene production that has received extensive attention. Molecular sieves with uniform porous structure, high thermal stability, and unique confinement capability have been proven to be ideal supports for well-dispersed active sites to generate efficient PDH performance. In this review, we describe the progress in the synthesis and PDH performance of metal-molecular sieve catalysts, including metal-mesoporous silica, metal-zeolite, and metal-hierarchical zeolite catalysts. The strategies in identifying and regulating active site microstructure and metalmolecular sieve interactions as well as their correlations with active site structure and PDH mechanism are introduced simultaneously. Finally, the current limitations and future opportunities of metal-molecular sieve materials in the PDH reaction are also discussed. This review is expected to provide some guidance for future catalyst design based on utilizing the molecular sieve's structural confinement to facilitate propane activation and active site stabilization.

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Propane direct dehydrogenation (PDH) has received much attention. How to effectively catalyze inert C–H bond activation is of great significance for industrial development. Pt-based catalysts show excellent activity but are limited by their expensive price. Cr-based catalysts are scarcely applied owing to their high toxicity. V-based catalysts are appropriate candidates for their cheap price and low toxicity, but they suffer from high energy consumption. The photothermal synergy effect induced by nonradiative relaxation is expected to make the C–H bond activation and hydrogen coupling process easier compared to bare thermal catalysis. Herein, a set of V/TiO2 nanoscale catalysts were synthesized. The optimized 3 wt % V/TiO2 catalyst (hereafter simplified as 3V) has a particle size of ∼26 nm, achieving a propylene production rate of 342 μmol·g–1·h–1 at 500 °C with UV–vis light radiation, which is 9.2% higher compared with bare thermal conditions. In situ radiation X-ray photoelectron spectroscopy (XPS) shows that photon injection leads to more electron-deficient V atoms (Vδ+, 5 > δ > 3). The strengthened Lewis acidity enhances the C3H8 activation as revealed by kinetic evidence and in situ C3H8-DRIFT measurements. The calculated molecular orbital diagrams show that the V atoms decrease the energy gap between the highest occupied orbital (HOMO) of C3H8 and the lowest unoccupied orbital (LUMO) of the model catalyst. This work describes an efficient photothermal synergy approach, specifically the nonthermal effect for promoting propane dehydrogenation.

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Hydrothermal process (HT) is an economical and simple method in upgrading agriculture wastes. The liquid product obtained from HT is interesting because of abundant active chemical group. The present work tried to co-heat the HT liquid product of cotton stalk (CS) with heavy crude oil to reduce its viscosity. The optimization study was performed to obtain the best condition of co-heating and mechanism study was completed by comparing the viscosity reduction efficiency and analyzing group composition of crude oil before and after co-heating with HT liquid products of CS, cellulose, hemicellulose and lignin. The results show that the crude oil viscosity reduced obviously after co-heating with CS-HT liquid product under the optimized condition (220°C, 1 h, 3 g treatment liquid, 30 ml crude oil). The preliminary mechanism study results suggest that the main function component of CS that cause viscosity reduction of heavy oil is lignin. The current work provides a new idea of lignocellulosic biomass upgrading and heavy crude oil viscosity reduction.

Graphynes (GYs) are a novel type of carbon allotrope composed of sp and sp2 hybridized carbon atoms, boasting both a planar conjugated structure akin to graphene and a pore‐like configuration in three‐dimensional space. Graphdiyne (GDY), the first successfully synthesized member of GYs family, has gained much interest due to its fascinating electrochemical properties including a greater theoretical capacity, high charge mobility and advanced electronic transport properties, making it a promising material for energy storage applications for lithium‐ion and hydrogen storage. Various methods, including heteroatom substitution, embedding, strain, and nanomorphology control, have been employed to further enhance the energy storage performance of GDY. Despite the potential of GDY in energy storage applications, there are still challenges to overcome in scaling up mass production. This review summarizes recent progress in the synthesis and application of GDY in lithium‐ion and hydrogen storage, highlighting the obstacles faced in large‐scale commercial application of GDY‐based energy storage devices. Suggestions on possible solutions to overcome these hurdles have also been provided. Overall, the unique properties of GDY make it a promising material for energy storage applications in lithium‐ion and hydrogen storage devices. The findings presented here will inspire further development of energy storage devices utilizing GDY.