Changgong Meng

Hydroformylation is a 100% atom-economy industrial process that converts olefins and syngas to aldehydes, typically catalyzed by homogeneous Rh phosphine or phosphite complexes, though catalyst recovery and ligand stability remain persistent challenges. Here, we theoretically investigate HRh(CO)2 fragments supported on black phosphorene (BP) that forms in situ via the reaction of Rh(CO)2(acac) (acac = acetylacetonate) with BP under hydroformylation conditions, as a heterogeneous single-site alternative. Using first-principles thermodynamics coupled with microkinetic simulations to treat the effect of temperature and content of the reaction feed, we demonstrate that the reversible and competitive coordination of CO and surface phosphorus atoms to the Rh center enables ethylene hydroformylation to proceed through both the classical Heck–Breslow pathway and a surface-P involving its variant, and the turnover frequency (TOF) for propanal is up to ∼15,000 h–1 at 450 K. Notably, the latter pathway, previously considered kinetically insignificant, contributes substantially to the TOF. In full agreement with the thermodynamic stability of the participating intermediates, the TOF increases with temperature and H2 content but decreases with CO content in the reaction feed. Furthermore, the near-quantitative propanal selectivity arises from the thermodynamically unfavorable formation of byproduct intermediates, which effectively suppresses the competing pathways. We expect these findings help to establish the principles for the rational development of heterogeneous single-site hydroformylation catalysts.

Enhancing the kinetics and mass transfer efficiency is the central issue in the research of the catalytic oxygen evolution reaction (OER). Here, an in situ hydrothermal transformation method for synthesizing ultra‐porous cobalt‐nickel silicate hydroxide (CNSH) with a layered double hydroxide (LDH) is demonstrated. This in situ variation from well‐crystallized carbonate to amorphous silicate hydroxide leads to a dandelion‐like structure originating from framework reconstruction as topotactic transformation process, defined as “karst cave effect”. Moreover, the specific coordination environment in CNSH not only enhances Metal‐Oxygen Covalency (MOC) for promoting lattice oxygen‐mediated mechanism (LOM), but also improves structural stability. CNSH demonstrates superior OER performance, including low overpotentials of 275 mV and 313 mV for current densities of 10 and 100 mA cm ⁻² , respectively, as well as exceptional long‐term stability for 800 h at 1 A cm ⁻² . This work provides an innovative and feasible pathway for the rational design of electrocatalysts with both porous structure and rapid kinetics for efficient and stable water oxidation.

Biomass‐derived hard carbon is a leading anode candidate for sodium‐ion batteries. However, molecular‐level manipulation of carbonized precursors for further performance enhancement remains challenging. Here, we depart from conventional passive modification strategies and introduce a radical‐mediated structure‐guided synthesis approach. By leveraging polyethylene glycol as an in situ, molecular‐weight‐tunable radical source, we demonstrate that thermally generated exogenous radicals actively graft onto the developing carbon framework during pyrolysis. This “molecular surgery” enables precise, one‐step control over both graphitic microcrystal growth and closed pore architecture. Crucially, we establish a direct correlation between polyethylene glycol molecular weight, the speciation/concentration of in situ generated radicals, and the resulting sodium storage performance. Aliphatic/aromatic radicals promote carbon layer extension (La increases from 11.2 to 12.4 nm), while oxygen‐containing radicals facilitate pore network reconstruction via gas evolution. The optimized hard carbon delivers a high reversible capacity of 356 mAh g ^{− 1} with a plateau capacity of 245.3 mAh g ^{− 1} and an initial Coulombic efficiency of 90.11%. A full cell paired with a Na ₃ V ₂ (PO ₄ ) ₃ cathode achieves an energy density exceeding 265 Wh kg ^{− 1} . This universally applicable, one‐step strategy provides a new design principle for rational engineering of high‐performance hard carbon anodes.

Poor inherent conductivity, sluggish reaction kinetics, and structural instability have widely limited the use of layered δ ‐MnO ₂ in aqueous magnesium‐ion storage. Inspired by the d‐band center ( ε _d ) theory, this study synthesizes oxygen defective W‐doped δ ‐MnO ₂ (O _d ‐WMO) with a tailored d‐band center through a two‐step hydrothermal‐calcination method to address the above bottlenecks. The results of theoretical calculation demonstrate that synergistic modulation mechanism of tungsten doping and oxygen defects not only promotes the upward shift of the ε _d of Mn, significantly enhancing the adsorption capacity for Mg ²⁺ , but also simultaneously strengthens Mn‐O bonds, thereby markedly improving structural stability. Moreover, the synergistic modulation effect of the two also dramatically narrows the band gap, lowers the migration energy barrier, as well as speeds up the dynamics of charge transport/ion diffusion. As expected, O _d ‐WMO demonstrates outstanding structural durability and remarkable storage capacity (185.2 mAh g ⁻¹ at 0.1 A g ⁻¹ ). Moreover, 3,4,9,10‐perylenetetracarboxylic diimide (PTCDI) as anode to assembled O _d ‐WMO//PTCDI full cell also exhibit a stable working state. This study uncovers the synergistic modulation mechanism of doping and defect engineering on MnO ₂ 's ε _d , makes up for the limitation in current research that focuses solely on individual regulatory effects of doping or defects. It provides valuable insights for the rational design of high‐performance electrode materials for AMIBs and other electrochemical energy storage systems via d‐band center engineering.

Transition metal silicates (hydroxides) have been extensively studied as electrode materials, particularly as electrocatalysts for the oxygen evolution reaction (OER). However, their synthesis has not been thoroughly explored, leading to inconsistent products under different synthetic conditions. In this work, we elucidate the formation mechanisms of three types of cobalt silicates (hydroxides) and two bimetallic silicate hydroxides and establish their specific synthesis conditions. We demonstrate that the form and dissolution kinetics of the metal sources during the sacrificial template process are critical factors governing the synthesis. They determine the Co/Si ratios in the products and whether two metals can uniformly distribute in bimetallic silicate hydroxides. Moreover, we illustrate that the bimetallic effect modulates the energy difference between the d-band center of cobalt and the p-band center of oxygen (Δε_d-p), along with the filling of the e_g* orbitals, thereby enhancing the OER performance. The present work significantly advances the research and application of transition metal silicate (hydroxide) materials.

Aqueous zinc-based energy storage systems boast high theoretical specific capacity, low cost, inherent safety, and environmental compatibility, making them highly promising for next-generation energy storage and conversion applications. However, challenges such as dendrite formation, hydrogen evolution reactions (HER), and corrosive passivation on the zinc metal surface impede their commercial viability. To tackle these issues, we have developed hollow nanotubular magnesium silicate interfacial layer on the zinc metal anode (Zn@MgSi). This unique layer structure and the negatively charged surface of MgSi strips H₂O molecules from [Zn(H₂O)₆]²⁺ to facilitate the desolvation process. Zn²⁺ is temporarily immobilized at the MgSi sites to avoid random diffusion. The electric field guides the uniform distribution of Zn²⁺ and the ion channel guarantees rapid transport. Ultimately, the Zn²⁺ flux is co-regulated to achieve dendrite-free deposition. Consequently, the Zn@MgSi symmetric cell exhibits enhanced zinc ion transfer number (0.64), improved performance, and the lifespan exceeding 1600 h at 1 mA cm⁻². It also demonstrates robust cycling stability, operating for 200 h at higher current densities (5 mA cm⁻²). Zinc-ion hybrid capacitors assembled with Zn@MgSi electrodes achieve high cycling stability with over 5000 cycles. This study underscores the effectiveness of the artificial interfacial layer strategy in stabilizing zinc metal anodes, providing fundamental understanding for the development of advanced aqueous zinc-ion hybrid capacitors.