This work studies the reaction mechanism of the formation of xylenes from trimethylcyclopentane on the [GaH]2+ active site of Ga-ZSM-5 using the ONIOM (ob97xd/6-31G(d,p):pm6) method. The results show that the rate-determning step in the process from trimethylcyclopentane to xylene to produce o-xylene, m-xylene and p-xylene is entirely the ring expansion process. m-xylene is the easiest to produce, followed by p-xylene, and finally o-xylene. This result indicates that a large amount of xylene obtained in the experiment comes from the methylation of toluene, rather than directly generated from trimethylcyclopentane. Our discovery provides a new understanding of the formation of xylene during MTA on Ga-ZSM-5 catalysts.

Oxidative coupling of methane (OCM) serves as a key process for converting methane into C2+ hydrocarbons. However, achieving high C2+ yields remains challenging. This work develops a strategy to enhance OCM performance of La-based catalysts by introducing F to increase superoxide/peroxide (O2-/O22-) species concentration. Optimal F addition inhibits surface Ba accumulation and promotes its dispersion, thereby enhancing the basicity of the catalyst surface. This facilitates O2 activation to O2-/O2 2- species, which are directly correlated with CH3 radical generation, and ultimately governs OCM efficiency. Compared to pure La2O3, the Ba0.1/La-F0.55 catalyst exhibits higher O2-/O2 2- concentration, increasing CH3 radical formation and markedly improving C2+ yield of 18.3% at 650 degrees C. DFT calculations further reveal that the incorporation of Ba and F into La2O3 modifies the reactivity of surface oxygen species, facilitating CH4 dissociation and CH3 radical formation, thereby significantly boosting OCM performance. These findings unravel the fundamental roles of O2-/O2 2- species and CH3 radical in OCM reaction.

The propane dehydroaromatization over HZSM-5 zeolite offers a promising way for producing aromatics. The key to enhancing the aromatic yield lies in elucidating the structure-performance relationship between the Br & Oslash;nsted acid distribution within different pore channels and propane dehydroaromatization performance, including intrinsic reaction activity and diffusion rate. In this study, the propane dehydroaromatization process over HZSM-5 with Br & Oslash;nsted acid in different pore channels is explored by combining density functional theory (DFT) and molecular dynamics (MD) methods. The results indicate that the acid distribution within different pore channels of HZSM-5 has little effect on the propylene formation capability. 4-Methyl-1-pentene is the most probable C6 olefin intermediate via the propylene polymerization. The HZSM-5 with Br & Oslash;nsted acid at the T12 (intersection cavity) and T8 (straight channel) sites exhibits excellent dehydrogenation activity for C6 olefins, with only the T12 acid site being also highly active for propylene polymerization and C6 olefin cyclization reactions. A stronger confinement effect exerted by the pore channel environments within HZSM-5 on reactant molecules renders the dehydrogenation reaction more difficult. The HZSM-5 with the T10 (sinusoidal channel) acid site is more favorable for the diffusion of benzene out of the straight channel compared to the T12 and T8 acid sites. This study offers a valuable perception into the catalytic roles of Br & Oslash;nsted acid and confinement effect in the different pore channels of the HZSM-5, while also greatly benefiting the design of high-performance catalysts for propane dehydroaromatization.

The migration of oxygen species in lanthanum oxide (La2O3) catalyst plays a pivotal role in sustaining active oxygen supply for oxidative coupling of methane (OCM) reaction, yet its atomic-scale mechanism has long remained elusive owing to the inability of conventional ab initio molecular dynamics simulations to capture such long time-scale dynamic processes. To address this challenge, we develop a high-precision deep potential (DP) function by an active learning strategy, which can achieve density functional theory (DFT)-level accuracy in predicting energies, atomic forces and oxygen migration barriers. Based on the developed DP function, deep potential molecular dynamics simulations reveal that oxygen dynamic migration is synergistically regulated by temperature and oxygen vacancies depth, where La2O3 exhibits a well-ordered bidirectional "lattice oxygen relay migration" mechanism at 923.15 K. This bidirectional migration establishes a dynamic self-adaptive regulation of surface oxygen concentration, ensuring continuous active oxygen supply meanwhile preventing surface oxygen excessive accumulation, which unravels the essential cause of the optimal reaction temperature (similar to 923.15 K) observed in the experiment for La2O3 to achieve high C2+ hydrocarbon selectivity and catalytic activity. The structure-activity relationship between oxygen dynamic migration and catalytic performance is established, which provides a novel theoretical design strategy to overcome the long-standing "activity-selectivity" trade-off in the OCM reaction through the precise regulation of oxygen vacancies and temperature.

Single-atom catalysts (SACs) have shown great promise for ethane dehydrogenation (EDH), owing mainly to their near-100% atomic utilization, precisely tunable active sites, and superior catalytic performance. Studies reveal that the nature of active metals, the properties of support and the coordination environments are critical factors affecting EDH performance. Among various supports, graphene has emerged as an ideal support material due to its excellent thermal stability and flexible, tunable coordination structure. While previous research has explored the effects of different active metals and coordination environments, a systematic understanding of their underlying principles is still lacking due to fragmented data. To bridge this gap, this work constructed a systematic, comprehensive database of heteroatom-doped graphene-supported SACs, covering five representative metal single atoms and 51 distinct coordination environments grouped into six major categories. Through high-throughput calculations, multi-dimensional data were systematically obtained, including elementary reaction energies, vibrational frequencies, density of states and Bader charges. A rigorous quality control system was implemented at both the parameter-setting and computational result levels. The database also provides complete raw calculation files, offering reliable data support for in-depth analysis of the catalytic performance, structure-performance relationship and reaction mechanisms of heteroatom-doped graphene-supported SACs in EDH.

Cu-based catalysts showed high C2H4 selectivity for C2H2 semi-hydrogenation, while they still face low activity and easy green oil formation. To solve these issues, this study examines C2H2 semi-hydrogenation on a series of Cu@nPd1Cu3(n = 1-4) catalysts with varying shell thickness; Cu and Pd1Cu3 intermetallic catalysts were studied for comparison. The results demonstrated that Cu@2Pd1Cu3 exhibited superior C2H4(g) production activity and selectivity, along with significantly suppressed green oil formation, attributing to that Pd1Cu3 shell spatially isolates Pd active sites, thereby structurally inhibiting C2H4 over-hydrogenation and C2H2 polymerization; moderate charge transfer between the core and shell modulates key intermediate adsorption behavior, thereby electronically tuning catalytic properties. kMC simulations identify optimal operating conditions for highperformance Cu@2Pd1Cu3. This study highlights the advantages of core-shell architecture over single-metal (Cu) and intermetallic (Pd1Cu3) catalysts in simultaneously balancing activity, selectivity, and stability. These findings provide structural insights into rational design and screening of high-performance catalysts in C2H2 semi-hydrogenation.

The cycloaddition of CO2 with ethylene oxide is an atom-economical reaction. Although halogen-containing catalysts, especially ionic liquids (ILs), show superior activity, yet its mechanism and the fundamental origin of the halogen effect, as well as a systematic comparison with halogen-free systems remain unclear. Herein, DFT calculations systematically compare halogen anions (F-, Cl-, Br-, I-) and halogen-free anions (OAc-, GA(-), BA(-), BC-, SA(-)) paired with various cations in the cycloaddition of CO2 with EO. The results show that within a given cation framework, the activity trend follows I- > Br- > Cl- > halogen-free anions > F-, with EO ring-opening as the rate-determining step. Electronic analysis reveals the catalyst's HOMO-LUMO gap correlates with the barrier of EO ring-opening step. At the transition state of EO ring-opening step, active halogen anions (especially I-) act as electron donors, populating the C-O sigma* orbital of EO via a direct HOMO (anion) -> LUMO (EO) electron-transfer channel to weaken the bond and lowering the barrier. IGMH and AIM analyses reveal a synergistic catalytic cycle: "anion releases cation -> cation enhances EO stabilization -> collective reduction of the ring-opening energy barrier". This work provides an integrated electronic-spatial-energetic perspective for designing efficient, halogen-free catalysts. The predictive power of this mechanism is further demonstrated by the rational design of a carboxyl-functionalized halogen-free catalyst with a computed barrier lower than that of benchmark halogen systems.

Oxidative coupling of methane (OCM) is an effective means of methane utilization. Probing the formation and evolution of oxygen species on catalysts is essential for understanding OCM reaction process. This study reported the synthesis of La 0.8 Ce 0.2 O 1.5+delta catalysts with controlled lattice strains, and revealed the strain effect on modulating surface oxygen species and OCM performance. Herein, O 2 was firstly activated into surface chemisorbed oxygen species (O S-C ), part entered bulk phase and converted into bulk lattice oxygen species (O B-L ). During reaction process, the O B-L species can migrate and convert into surface lattice oxygen species (O S-L ). The relative ratio of O B-L to O S-L species affect the number of surface oxygen vacancies, thereby controlling reaction performance. Catalysts with larger grain sizes cannot fully replenish consumed O S-L with O B-L species due to lower O B-L content and slower migration rates, leading to an increase in surface oxygen vacancies, which promotes the generation of more O S-C species, enhancing CH 4 activation while limiting O S-L -mediated overoxidation, thereby improving CH 4 conversion and C 2+ hydrocarbon selectivity. This study provides new insights into understanding oxygen species formation and evolution mechanisms in OCM reaction and facilitates the rational design of low-temperature, high-efficiency OCM catalysts.

Metal oxide catalysts have emerged as highly promising materials for the CO2 cycloaddition reaction, owing to their tunable composition, facile separation, reusability and low cost. Previous studies have identified that the type and ratio of metal dopants, surface defect characteristics and crystal plane orientation are critical factors affecting catalytic performance. Despite this potential, systematic investigations into metal oxide catalysts for CO2 cycloaddition remain limited and a comprehensive understanding of the underlying reaction mechanisms is hindered by the lack of extensive, well-curated datasets. To address this gap, this study establishes a systematic and comprehensive dataset of metal oxides including layered double hydroxide (LDH) and ZnO catalysts, encompassing variations in metal dopant type and ratio, defect characteristic and crystal plane orientation. Through high-throughput calculations, we have generated a robust multi-dimensional dataset containing elementary reaction energies, vibrational frequencies, Bader charges and density of states. A rigorous two-tiered quality control protocol is applied to both computational parameter settings and output results, ensuring the integrity and reliability of the data. This dataset, providing complete raw calculation files, offers a reliable foundation for exploring catalytic performance, structure-performance relationships and reaction mechanisms of metal oxide catalysts in CO2 cycloaddition.

Layered double hydroxides (LDHs) have emerged as promising catalysts for the cycloaddition of CO2 with ethylene oxide (EO) to produce ethylene carbonate (EC), yet the rational design of high-performance LDH-based catalysts remains challenging. In this study, we propose a DFT-accelerated machine learning framework to establish interpretable descriptors that elucidate the underlying structure-performance relationship. The results show that the XGBR model achieves the best prediction accuracy and generalization ability within the range [97.1, 191.1]. Three RF-enhanced descriptors-lambda for M2+ from the physicochemical parameter (VE) and electronic parameters (dO(CO2)-C(EO), epsilon p,O, and Delta C(EO)), effectively capture the catalytic activity of various M2+x M3+-LDH materials in the CO2 cycloaddition reaction. These descriptors accelerate the high-throughput screening of the efficient, halogen-free, and solvent-free M2+ catalysts and provide clear guidance for optimizing catalyst performance.

Oxidative coupling of methane (OCM) to C2+ hydrocarbons is of great significance for the high-value utilization of methane. La2O3 is an effective OCM catalyst, while its low C2+ selectivity and easy over-oxidation to produce COx limit its application. This work introduces a BaCO3/La2O3 catalyst that modulates surface reactive oxygen species on La2O3, thereby mitigating CH4 over-oxidation to improve C2+ hydrocarbon selectivity. The optimized La5Ba5 (composed of a BaCO3-La2O3 heterostructure) catalyst achieves 61.0% C2+ selectivity, 32.9% CH4 conversion, 20.1% C2+ yield and 30 h stability at 800 degrees C with an inlet molar ratio of CH4/O2/N2 = 3/1/1 and a space velocity of 160000 mL & sdot;g-1 & sdot;h-1. Combined characterizations including in situ O2-XRD, XPS, TPSR, VUV-SPIMBMS and DFT calculations reveal that the BaCO3-La2O3 heterostructure promotes the transformation of BaCO3 to BaOx(CO3)1-x, which passivates lattice oxygen on La2O3 catalyst to suppress the over-oxidation of CH3* intermediates while promoting the formation of chemisorbed oxygen species, facilitating CH3* desorption to CH3 & sdot; radical. This synergistic effect effectively inhibits COx formation and significantly enhances C2+ selectivity. This study provides a new strategy for designing highly selective La2O3-based OCM catalysts through lattice oxygen regulation, opening promising pathways for methane conversion.

Catalytic conversion of biomass‑derived diketene into aromatics represents a novel and economical pathway for aromatics production. Aromatic selectivity of 50.4

The oxidative coupling of methane (OCM) reaction is hindered by fundamental scientific challenges including the difficulty in CH4 activation and the inability to inhibit deep oxidation. In this study, the LaAlO3 catalyst, which exhibits excellent low-temperature activity and thermal stability, was selected. The structure-activity relationship among the catalyst surface structure, surface oxygen species, and reaction performance was systematically explored using DFT calculations and microkinetic modeling. The results indicate that different surface terminations (LaO- and AlO2-terminations) of LaAlO3 catalyst exhibit distinct oxygen species. The evolution pathway of oxygen species on the LaO-termination surface proceeds as O2--> O2--> O22--> O2-, while on the AlO2termination surface it follows O2--> O22--> O2-. Among these oxygen species, O2- plays a dominant role in CH4 dissociation. The LaO-termination demonstrates three major advantages: higher CH4 dissociation activity, superior C2H4 production activity, and enhanced selectivity, establishing it as the dominant active termination. Doping the LaO-termination catalysts with alkaline earth metals (Mg, Ca, Sr) do not alter the types of oxygen species but significantly modulate reaction characteristics. Bader charge of surface O2- serves as an effective descriptor for predicting CH4 dissociation capability of M/LaO-p-O2- catalysts. Under realistic conditions, due to fewer surface free sites, Ca/LaO-p-O2- exhibits a lower C2H4 formation rate than Sr/LaO-p-O2-.

The catalytic conversion of biomass-derived diketene into light olefins represents an innovative and economically attractive route for light olefin synthesis. Over both SSZ-13 and SSZ-39 zeolites, which feature three-dimensional, 8-membered ring pore structures, a 94.0% selectivity toward light olefins in the hydrocarbon products is achieved, marking one of the highest values ever reported. Notably, SSZ-13 exhibits superior catalytic stability. Compared to SSZ-39, SSZ-13 possesses a larger specific surface area and pore volume, along with a lower content of high-ring aromatic pyrene species. These properties may facilitate the diffusion of reactants and products, and inhibit the accumulation of coke precursors on SSZ-13. A plausible reaction pathway is proposed, in which diketene decomposes into acetyl group and ketene intermediate, followed by C-C coupling to generate light olefins. This work offers a promising strategy for light olefin production from biomass-derived diketene.

Pt-based catalysts are widely employed in ethane direct dehydrogenation (EDH) for their high activity, but their practical application is limited by high cost, susceptibility to coking and rapid deactivation. Transition metal carbide V8C7, known for its Pt-like electronic properties, offers a promising alternative. In this work, we combined DFT calculations and machine learning (ML)-assisted theoretical phase diagram analysis to systematically assess the stability of 27 single-atom doped M-V8C7 structures and their EDH catalytic performance. While the V8C7(110) surface showed appreciable EDH activity, it suffered from low C2H4 selectivity. Among the doped catalysts, 20 were identified as thermodynamically stable, particularly Rh-V8C7 exhibited enhanced activity and high C2H4(g) selectivity. Electronic structure analysis identified Bader charge and d-band center as effective activity descriptors for the M-V8C7 series. Notably, Rh-V8C7 demonstrates Pt-like behavior in both catalytic function and electronic structure, highlighting its potential as an efficient and economical alternative to Pt-based catalysts for EDH.

The use of anatase-rutile mixed-phase TiO2 (P25) as a support improves both CO conversion and selectivity toward low-carbon alcohols (C-1-C-5 mixed alcohols) during syngas conversion over Cu-Fe bimetallic catalysts. A 61.4% selectivity to low-carbon alcohols was obtained at a CO conversion of 35.0%. The low-carbon alcohol yield (21.5%) over CuFe/P25 is 31 and 3 times higher than the yields over Cu-Fe catalysts supported on pure anatase TiO2 and pure rutile TiO2, respectively. The anatase-rutile synergy in P25 contributes to the high dispersion of Cu-Fe species and facilitates electron transfer from the P25 support to both Cu-0 and FeCx active sites via metal-support interaction. CuFe/P25 enhances both the capabilities of CO adsorption, dissociation, and non-dissociative insertion and the formation of CHx, CHO, and HCOO intermediates. These findings suggest that tuning the crystalline phase of the support constitutes a rational strategy for enhancing the catalytic activity of the metal sites.

The development of halogen/solvent-free heterogeneous catalysts for CO2 cycloaddition with ethylene oxide is crucial to address the product separation and halogen residues contamination in the industrial homogenous systems. In this work, DFT + U calculations and CatMAP are employed to investigate catalytic performance of CO2 cycloaddition reaction over pristine ZnO and M-ZnO (M = Mg, Ca, Al, Ga, Fe, Co, Ni and Cu) catalysts under halogen/solvent-free conditions. The results demonstrate that the types of metal dopant M and crystal facet can effectively regulate acid-base strength of M-ZnO catalysts to enhance catalytic performance, attributing to that the activated CO2 delta- species achieve a halogen-like effect, where strong acid sites paired with weak basic sites present optimal synergistic effects toward CO2 cycloaddition. Among the catalysts investigated, the AlZ2 exhibits superior activity and selectivity at the optimal conditions of 523.15 K and pCO2/pEO = 15. This work establishes a rational design strategy for halogen/solvent-free metal oxide catalysts in CO2 cycloaddition.

Methane dehydroaromatization (MDA) represents a highly promising and environmentally favorable technology for producing benzene, toluene, and xylene (BTX) from non-petroleum feedstocks. Precise control over the structure and distribution of active sites on Mo-modified HZSM-5 represents a fundamental challenge for simultaneously enhancing methane conversion and C2 selectivity in MDA. This study employs density functional theory (DFT) calculations to investigate systematically the effects of different Lewis acid (MoC2+, MoOC2+, Mo2C22+) and the corresponding distribution within HZSM-5 on methane to ethylene reaction, proposing the local microenvironment engineering through a strategic modulation Mo species and spatial distribution. The results indicate that the active C atom in Lewis acid participates in ethylene formation as the optimal pathway for ethylene formation. Highly dispersed MoC2+ and Mo2C22+ modified HZSM-5 exhibit better catalytic performance, especially exhibiting particularly outstanding catalytic performance when MoC2+ positioned at T6-T7 site. Furthermore, a synergistic mechanism between C and Mo for methane activation is elucidated, in which the electron cloud overlap between active C atom and methane operates in concert with the strong electronic interaction between Mo and methane to enable efficient activation of methane first C-H bond. Interaction region indicators (IRI) and diffusion kinetic studies indicate that products experience weak steric hindrance within T6-T7-MoC2+/HZSM-5 catalyst, exhibiting high diffusion properties.

To meet the integrated requirements of automotive displays for zero VOC, anti-glare properties, wide viewing angles, and high abrasion resistance, while overcoming the limitations of mechanical strength and haze in traditional WPUA coatings, this study employs a stepwise in-situ hybridization strategy. Given the significant variations in performance demands across diverse application fields such as architecture, energy, transportation, and healthcare, the research further explores precise methods for performance regulation. By constructing an interpenetrating network using KH-550 and TEOS, a WPUA/SiO2 hybrid coating was developed. Combined with density functional theory (DFT) calculations and reduced density gradient (RDG)/interaction region indicator (IRI) analysis, the synergistic mechanism and reaction pathway between KH-550 and TEOS were elucidated at the electronic level. Experimental results demonstrate that at a KH-550: TEOS molar ratio of 1 : 2, the coating exhibits optimal overall performance, including grade 0 adhesion, 84 HD hardness, 7.3 mg wear loss, and over 90% transmittance. Additionally, with the molar ratio of KH-550 to TEOS fixed at 1 : 2, a systematic comparison of different silane coupling agents revealed distinct advantages: the KH-550 system delivers outstanding adhesion (grade 0) and high transmittance (>90%), with a gloss level of 105 GU; the KH-560 system excels in hardness (86 HD) and resistance (6.9 mg mass loss) with a gloss of 86 GU; and the KH-590 system offers a balanced performance in transmittance (>90%) and water resistance (water absorption 1.2%, water contact angle 98.4°), together with a gloss of 98 GU. This study provides a theoretical foundation and material design guidelines for developing functional coatings tailored to various application scenarios.

The catalytic performance of metal sulfides (MxSy) in specific reactions is significantly influenced by their surface structures, chemical compositions, and surface defects. While palladium sulfides have been the only metal sulfides reported so far for the selective hydrogenation of alkynes, it remains unclear whether other MxSy compounds can also serve as efficient catalysts for C2H2 selective hydrogenation. In this work, we systematically investigated C2H2 selective hydrogenation using 17 different types of MxSy catalysts, examining the effects of surface structure (including exposed termination and crystal facet), surface composition (metal type and M: S ratio), and surface defects through DFT calculations and AIMD simulations. Our results reveal the intrinsic reasons behind how the surface properties of MxSy regulate catalytic performance, which are mainly attributed to distinct ensemble and/or ligand effects, as supported by analyses of geometric and electronic properties. The adsorption strength of C2H2 on MxSy surfaces is proposed as a simple descriptor to qualitatively evaluate C2H4 generation activity. Four catalysts—CoS2(110), Co9S8(111), Rh2S3(110) and Rh3S4(100)—were identified as promising candidates. They not only exhibit superior C2H4 generation activity and selectivity, but also effectively suppress green oil formation, thereby maintaining better catalytic stability and structural thermal stability. These findings provide essential structural insights for the design and screening of high-performance MxSy catalysts for C2H2 selective hydrogenation.