Xinggui Zhou

CO ₂ hydrogenation to aromatics via methanol is a promising alternative for the low‐carbon and sustainable production of aromatics. Herein, a two‐scale particle‐resolved computational fluid dynamics model is developed to reveal the complex transport‐reaction in the fixed‐bed reactor for this cascade reaction (i.e., CO ₂ hydrogenation to methanol and methanol‐to‐aromatics) over tandem In ₂ O ₃ ‐HZSM‐5 catalysts. The results show that using the layered packing configuration with In ₂ O ₃ positioned upstream better matches the features of this reaction, exhibiting a 98% increase in the yield of aromatics compared with the random packing configuration. As it allows the methanol‐to‐aromatics reaction occurs over HZSM‐5 at a high methanol concentration. A In ₂ O ₃ to HZSM‐5 ratio of 1 can well coordinate the two cascade reaction steps. Besides, alleviating diffusion limitations via adopting Raschig ring pellet, small pellet size and large pore size can facilitate CO ₂ consumption and aromatics generation, as well as suppress reverse water gas shift reaction.

In nitration processes, continuous-flow and microchannel reactors reduce hazardous inventory and improve heat transfer. However, their short residence times may necessitate the use of highly concentrated fuming nitric acid to achieve rapid conversion. This creates an inherent safety trade off, particularly when coolants circulated close to the process stream are assumed to be chemically inert. Accidental coolant ingress may therefore introduce an additional reactive pathway that is not represented by conventional loss of cooling scenarios. In this study, differential scanning calorimeter (DSC), antiexplosive reaction calorimeter (E-RC), and liquid-nitrogen-assisted accelerating rate calorimeter (ARC) were used to evaluate the incompatibility between fuming nitric acid above 95 wt % and three representative coolants, namely potassium formate solution, ethylene glycol solution, and calcium chloride brine. Potassium formate showed the fastest initial reaction and most intense gas generation, with a combined heat release of approximately −620 to −572 J/g. Ethylene glycol exhibited the greatest overall heat release, reaching −3236.2 to −3123.2 J/g. Under near-adiabatic conditions, the ethylene glycol system exhibited an apparent onset near −10 °C and a maximum self-heating rate of approximately 2400 °C/min. In contrast, calcium chloride brine showed limited reactivity dominated by mixing and dilution effects. These results demonstrate that reactive coolant ingress can rapidly generate localized hot spots and pressure buildup in nitration processes, which is particularly critical for compact continuous-flow reactors with small channels. The obtained calorimetric and kinetic data provide guidance for coolant selection, assessment of the hazard severity of identified leakage scenarios, and inherently safer design of microchannel nitration processes.

Enantioselective liquid–liquid extraction (ELLE) based on cyclodextrin host–guest recognition is a promising green strategy for chiral resolution. However, its industrial application is often hindered by restricted chiral recognition efficiency and ill-defined interfacial mass transfer mechanisms. In this work, a multiscale approach─integrating macro-equilibrium experiments, molecular dynamics simulations, and quantum chemical calculations─was employed to decode the interfacial molecular interactions and their decisive roles in the ELLE of ibuprofen. The interface was regulated and reconstructed through the introduction of surfactants. The anionic surfactant SDS shortened extraction equilibrium time by approximately 30%, while the facial amphiphilic NaDC extended equilibration but improved the enantiomeric excess. MD simulations revealed that the addition of SDS and NaDC increased the interfacial thickness from 0.41 nm by 1.23 and 1.51 times, respectively. Via umbrella sampling, the chiral migration process exhibited characteristic free-energy changes of approximately −11.48 kJ·mol–1 and +35.58 kJ·mol–1 when transferring from the organic and aqueous phases to the interface, respectively. Furthermore, quantum chemical analysis quantified the interaction energy differences, demonstrating that steric hindrance and hydrogen-bonding intensity variations drove the observed changes in equilibrium parameters. These findings establish a conceptual microscopic model for interface-mediated chiral partitioning, providing a robust theoretical framework for optimizing separation efficiency and process intensification in ELLE systems.

Direct propylene epoxidation with H ₂ and O ₂ over Au/TS‐1 is an attractive alternative for the production of propylene oxide (PO), and acquiring its reaction kinetics is essential for the industrialization of this process. Herein, its intrinsic kinetics are established by using Au/TS‐1‐B with template‐blocked micropores, which enables the elimination of catalyst deactivation and micropore diffusion effects. The established reaction network shows that propanal and acetone are formed via PO isomerization and propylene‐derived hydro‐oxidation, and CO ₂ mainly originates from PO deep oxidation on Au sites. The co‐feeding experiments reveal that there exist strong and weak adsorption for C ₃ H ₆ or PO on Au sites, and competitive adsorption of C ₃ H ₆ , PO, and H ₂ O on Ti sites. Based on the above understanding, a Langmuir–Hinshelwood intrinsic kinetic model is proposed and validated. This model exhibits excellent applicability to well predict the data obtained from our kinetic experiments and those reported in the literature.

CO₂ hydrogenation over earth-abundant Ni catalysts is attractive for CO-based fuel synthesis, but Ni intrinsically favors methanation. Here we show that ordered Ni₃Sn₂ intermetallics tune Ni–CO electron back-donation and switch CO₂ hydrogenation from CH₄ formation to the reverse water–gas shift reaction. Atomic-resolution microscopy and X-ray absorption spectroscopy reveal disruption of extended Ni–Ni ensembles by Sn, while spectroscopy and theoretical calculations show that Ni–Sn d-p hybridization downshifts the Ni 3d band and weakens Ni→CO 2π* back-donation. The Ni₃Sn₂ catalyst achieves CO₂ conversion approaching thermodynamic equilibrium with nearly 100% CO selectivity and remains stable for 300 h. In situ infrared spectroscopy, steady-state isotopic transient kinetic analysis and theoretical calculations indicate that H-assisted CO₂ activation, spectator-like formate species and facile CO desorption underpin the CO-selective pathway. Similar behavior over Ni–Ga and Ni–In catalysts suggests a general back-donation strategy for redirecting Ni-based CO₂ hydrogenation.

Electrocatalytic hydrogenation can upgrade oxygenated biomass molecules without pressurized H2 using renewable electricity, but selectivity and energy efficiency are limited by competition with the hydrogen evolution reaction through the shared surface-hydrogen intermediate (H*). Here we develop a data-guided and interpretable strategy to design Cu-based catalysts that balance H* supply and utilization by targeting an intermediate H* binding regime. A density functional theory (DFT) data set of H* adsorption energies and descriptors trains an interpretable machine-learning model and identifies Pt1Cu as an intermediate-binding catalyst, which is synthesized on a Cu nanowire scaffold. The catalyst delivers Faradaic efficiency above 90% for selective hydrogenation of 5-hydroxymethylfurfural over a wide potential window while suppressing hydrogen evolution and byproduct formation. The design principle is further validated in the furfural hydrogenation. Operando spectroscopy and DFT calculations link the performance to adequate H* availability and moderated stabilization of hydrogenated intermediates, providing a transferable framework for electricity-efficient biomass upgrading.

The efficiency of tandem catalysis is fundamentally limited by the transport of transient intermediates. In the direct epoxidation of alkenes with H ₂ and O ₂ , in situ generated H ₂ O ₂ rapidly decomposes during diffusion, rendering most Ti active sites kinetically inaccessible and imposing a long‐standing performance ceiling. Here, we overcome this limitation by engineering hydrophobic transport channels via physical integration of a hydrophobic polymer with bifunctional Au/TS‐1 catalysts. This microenvironment accelerates H ₂ O ₂ migration away from hydroxyl‐rich surfaces toward remote Ti sites while suppressing nonproductive decomposition. Molecular dynamics simulation studies show that the diffusion of H ₂ O ₂ on hydrophobic surfaces is significantly higher than on hydrophilic surfaces, as reflected experimentally by a 25% increase in tandem H ₂ O ₂ efficiency. Moreover, the hydrophobic channels promote rapid desorption of epoxide products, suppressing ring‐opening reactions and carbonaceous accumulation, resulting in a stable ∼90% epoxide selectivity over 200 h. This strategy exhibits broad generality across Au–Ti bifunctional catalysts for alkene epoxidation using in situ generated H ₂ O ₂ , with an outstanding H ₂ utilization efficiency of 73.5% achieved over the Au/TS‐1‐B catalyst under the identical standard reaction conditions employed throughout this work. This work establishes diffusion control of metastable surface species as a principle for breaking intrinsic transport–decomposition trade‐offs in tandem catalysis.

The efficiency of tandem catalysis is fundamentally limited by the transport of transient intermediates. In the direct epoxidation of alkenes with H ₂ and O ₂ , in situ generated H ₂ O ₂ rapidly decomposes during diffusion, rendering most Ti active sites kinetically inaccessible and imposing a long‐standing performance ceiling. Here, we overcome this limitation by engineering hydrophobic transport channels via physical integration of a hydrophobic polymer with bifunctional Au/TS‐1 catalysts. This microenvironment accelerates H ₂ O ₂ migration away from hydroxyl‐rich surfaces toward remote Ti sites while suppressing nonproductive decomposition. Molecular dynamics simulation studies show that the diffusion of H ₂ O ₂ on hydrophobic surfaces is significantly higher than on hydrophilic surfaces, as reflected experimentally by a 25% increase in tandem H ₂ O ₂ efficiency. Moreover, the hydrophobic channels promote rapid desorption of epoxide products, suppressing ring‐opening reactions and carbonaceous accumulation, resulting in a stable ∼90% epoxide selectivity over 200 h. This strategy exhibits broad generality across Au–Ti bifunctional catalysts for alkene epoxidation using in situ generated H ₂ O ₂ , with an outstanding H ₂ utilization efficiency of 73.5% achieved over the Au/TS‐1‐B catalyst under the identical standard reaction conditions employed throughout this work. This work establishes diffusion control of metastable surface species as a principle for breaking intrinsic transport–decomposition trade‐offs in tandem catalysis.

Selective oxidation of n ‐butane to maleic anhydride (MA) is fundamentally limited by the activity‐selectivity trade‐off, and the origin of selectivity control remains debated. Here we show that surfactant‐mediated modification of vanadium phosphorus oxide catalysts can shift the reaction network toward MA by suppressing competing carbon oxides (CO _x ) formation. We establish a kinetic framework that explains this selectivity shift through coupled redox‐site balance and product‐branching kinetics. Kinetic analysis identifies the CO _x to MA branching parameter (𝛾) as a key descriptor of intrinsic selectivity and reveals that MA formation requires an ensemble instead of an isolated site. These results provide direct kinetic evidence that MA selectivity is governed not only by the electronic properties of the redox sites, but also by ensemble‐dependent transition‐state formation on the site domains. This work offers both a mechanistic interpretation and a practical model for the ensemble effect that influences MA yield in n ‐butane oxidation.

Sub‐nanometer metal clusters provide an effective platform to bridge the gap between isolated atoms and nanoparticles in heterogeneous catalysis. Herein, we report the rational construction of Ir‐based catalysts with precisely controlled nuclearity on defect‐rich nanodiamond@graphene (ND@G), including single atoms (Ir ₁ ‐ND@G), sub‐nanoclusters (Ir ₆ ‐ND@G), and well‐defined nanoparticles (Ir _N ‐ND@G), for the selective hydrogenation of m ‐dinitrobenzene. Advanced microscopy and spectroscopy confirm the precise structural evolution and electronic modulation of Ir species. Among them, Ir ₆ ‐ND@G exhibits good catalytic performance, achieving complete conversion with >98.5% selectivity toward m ‐phenylenediamine under mild reaction conditions and high stability. Combined experimental studies and DFT calculations reveal that sub‐nanoclusters provide optimal ensemble sites for strong substrate adsorption, efficient H ₂ activation, and facile product desorption while effectively suppressing undesired side reactions arising from partial hydrogenation and N–N coupling. This work demonstrates that sub‐nanometer Ir clusters effectively overcome the intrinsic activity–selectivity trade‐off and establishes a versatile strategy for designing high‐performance heterogeneous hydrogenation catalysts.