Metal-organic framework-based materials are promising catalysts for the photoreduction of CO2 into formic acid. However, they generally suffer from low catalytic activity in the absence of sacrificial agents, poor selectivity due to the lack of directionality of CO2 adsorption, as well as the requirement of expensive ligands in the synthesis. Herein, we report a low-cost defective Ti-Janus MOF (dTi-Janus) photocatalyst through ligand-deficiency strategy, which delivers an outstanding photocatalytic performance in CO2 photoreduction to formic acid (258.6 μmol g−1 h−1, 99% selectivity) without any sacrificial agent, far exceeding the levels that have been reported so far. Through extensive experimental investigations combined with DFT calculations, this study reveals that the superior photocatalytic activity of this Ti-Janus MOF catalyst stems from its unique unsaturated Ti-(O)5 configuration. This Ti-(O)5 microstructure features Ti-Janus configuration made of Ti-(O)3 from Ti-BPDC and Ti-(O)2 from TiO2. Thin layer of TiO2 is epitaxially grown at the edges of dominant Ti-BPDC nanosheets and connected by Ti atom to form a dual-phase structure, which greatly promotes charge separation and transfer. Significantly, the Ti-Janus structure supports selective linear CO2 through spatial confinement effects, effectively activating CO2→*OCHO intermediate and promoting HCOOH production. This study presents a cost-effective and highly active MOF catalyst preparation strategy, and provides new insights into the critical mechanisms of CO2 adsorption and activation during photocatalytic CO2 to formic acid.

Zn-based catalysts for CO2 hydrogenation to methanol are typically active yet face the challenge of the key formate (HCOO*) intermediate decomposing into CO at high temperatures, thereby suppressing methanol selectivity. In this work, we designed ZnO/MnO-MnCO3 interfacial sites via the in situ reconstruction of a ZnMn2O4 spinel precursor. The resulting catalyst exhibits enhanced methanol selectivity over 350 degrees C, significantly outperforming ZnGa2O4, ZnAl2O4, and ZnFe2O4 benchmarks. In situ DRIFTS and DFT studies reveal that the ZnO/MnO-MnCO3 interface markedly enhances the thermal stability of the adsorbed HCOO* species, effectively inhibiting its decomposition and promoting hydrogenation toward methanol. Furthermore, DFT calculations establish a linear correlation between the overall reaction energy for HCOO* decomposition and the experimental methanol selectivity, offering a key descriptor for catalyst design. This work highlights the crucial role of stabilizing formate intermediates at oxide interfaces for achieving high-temperature methanol synthesis and provides fundamental insights into the development of efficient CO2 hydrogenation catalysts.

Subnanometric Pt-based catalysts have garnered extensive attention for propane dehydrogenation (PDH) due to their higher activity compared to their nanoparticulate counterparts. Although introducing a second metal component can enhance their stability and tune the catalytic performance, the determination of precise localization of Pt clusters and identification of interactions between the Pt cluster and the second metal remain challenging in experiments, especially in the presence of a catalyst support. This work performed first-principles-based calculations to screen a series of subnanometric Ptn/M-MFI catalysts for PDH, in terms of structure stability, dehydrogenation activity, and propene selectivity. The complete reaction route analysis and microkinetic simulation further validated the reliability of the screening method. The calculation results demonstrate that Pt4/M-MFI candidates with M = Ge4+, Ga3+, Cu2+, Sn2+, and Fe3+ are catalytically more active for PDH, especially for introducing Cu into the MFI framework. Further analysis reveals that the catalytic activity of subnanometric Pt4/M-MFI catalysts for PDH closely correlates with the binding energy and charge transferred between the Pt cluster and the M-MFI zeolite support. The MFI zeolite confinement plays an important role in enabling the secondary-metal promotion of subnanometric Pt clusters. This work provides directional guidance for the future design of high-efficient PDH catalysts.

A chromium‐free catalyst for the high‐temperature water‐gas shift (HT‐WGS) reaction was developed using copper aluminate spinel synthesized via co‐precipitation. Powder X‐ray diffraction (PXRD) revealed that the material was amorphous when calcined at 500 °C but transformed into a well‐defined crystalline spinel structure at 800 °C. Scanning electron microscopy (SEM) and energy‐dispersive X‐ray spectroscopy (EDS) confirmed the formation of crystalline spinel morphology, which enhances thermal stability under HT‐WGS conditions. Hydrogen temperature‐programmed reduction (H 2 ‐TPR) showed a shift of the second copper reduction peak to a higher temperature, indicative of the robust nature of the spinel phase. Density functional theory (DFT) calculations further demonstrated that the spinel catalyst exhibits superior CO adsorption and H2O activation compared to its amorphous counterpart, thereby improving WGS activity. The catalyst calcined at 800 °C exhibited activity for both low‐ and high‐temperature WGS reactions; however, after H 2 reduction at 400 °C, it became selectively active for the HT‐WGS reaction. Long‐term stability testing confirmed excellent durability, maintaining an average CO conversion of 53.6% over 120 h at 400 °C, comparable to the 57% achieved by commercial Cr‐containing catalysts. These findings establish copper aluminate spinel as a robust, sustainable, and chromium‐free alternative for industrial HT‐WGS catalysis.

ABSTRACT The mechanism of propylene epoxidation catalyzed by distinct titanium (Ti) species within the TS‐1 framework was systematically explored through DFT calculations. To elucidate the reaction pathways, rate‐limiting steps, and the intricate relationship between the catalyst structure and performance, several mononuclear Ti active site models, namely TiO 4 , Ti‐IV, Ti‐V, and TiO 6 , were meticulously constructed. The calculation results revealed that for both TiO 4 and TiO 6 , the rate‐limiting step is H 2 O 2 activation, with barriers of 0.75 and 0.77 eV, respectively. In contrast, for Ti‐IV and Ti‐V, the rate‐limiting step is propylene epoxidation, with barriers of 0.74 and 0.47 eV, respectively. Notably, the Ti‐V species demonstrated optimal catalytic activity for both H 2 O 2 activation and subsequent epoxidation, whereas the other three Ti species exhibited comparable catalytic activities. The electronic property calculations provided a robust theoretical basis for the observed activity trends, aligning well with the activation barrier data. Furthermore, the presence of methanol solvent was found to have a remarkable promotional effect on H 2 O 2 activation, significantly altering the kinetic feature of the overall reaction. This effect made the highly coordinated Ti‐V and TiO 6 species particularly promising catalysts for this reaction.

Photocatalytic CO2 reduction to value-added C2 products represents a promising strategy for carbon resource utilization. Herein, we report a high-efficient first-principles screening of dual-atom-modified g-C3N4 catalysts, with Cu as the primary metal and over 40 different secondary metals (M), to identify optimal CuM/g-C3N4 compositions for selective C2 production. The screening workflow incorporated multiple descriptors, including thermodynamic stability, adsorption affinity for key intermediates, and free energy changes in critical hydrogenation steps. CuM/g-C3N4 (M = Fe, Co, Ru, Rh, Ir) were identified as the most promising candidates, with CuIr/g-C3N4 exhibiting the highest activity. Distinct Cu-M combinations showed different selectivity toward specific C2 products. CuIr/g-C3N4 and CuCo/g-C3N4 favored ethylene, CuRh/g-C3N4 promoted ethanol, and CuFe/g-C3N4 led to ethylene glycol. By contrast, CuRu/g-C3N4 was ineffective for CO2 reduction to C2. The developed high-efficient screening framework significantly accelerates catalyst discovery while preserving computational efficiency, offering a generalizable strategy for the rational design of highly selective dual-atom-based photocatalysts for CO2 reduction to C2 chemicals.

The mechanism of propylene epoxidation catalyzed by distinct titanium (Ti) species within the TS-1 framework was systematically explored through DFT calculations. To elucidate the reaction pathways, rate-limiting steps, and the intricate relationship between the catalyst structure and performance, several mononuclear Ti active site models, namely TiO4, Ti-IV, Ti-V, and TiO6, were meticulously constructed. The calculation results revealed that for both TiO4 and TiO6, the rate-limiting step is H2O2 activation, with barriers of 0.75 and 0.77 eV, respectively. In contrast, for Ti-IV and Ti-V, the rate-limiting step is propylene epoxidation, with barriers of 0.74 and 0.47 eV, respectively. Notably, the Ti-V species demonstrated optimal catalytic activity for both H2O2 activation and subsequent epoxidation, whereas the other three Ti species exhibited comparable catalytic activities. The electronic property calculations provided a robust theoretical basis for the observed activity trends, aligning well with the activation barrier data. Furthermore, the presence of methanol solvent was found to have a remarkable promotional effect on H2O2 activation, significantly altering the kinetic feature of the overall reaction. This effect made the highly coordinated Ti-V and TiO6 species particularly promising catalysts for this reaction.

Interfacial catalysts show considerable potential for the synthesis of multicarbon products from CO2 hydrogenation by leveraging synergistic effects in C═O bond activation and C-C coupling. However, controllably constructing such interfaces under operational conditions remains highly challenging. Here, we engineer a Cu(0)-Co2C interfacial architecture through a reaction-induced reconstruction strategy. During CO2 hydrogenation, Co-Cu oxides are initially reduced to metallic Co(0) and Cu(0), with the K promoter unsealing the in situ carburization of Co(0) to form Co2C. An outside-in carburization mechanism is elucidated and can be manipulated by tailoring the Co(0)-Cu(0) interaction. Compared to Co(0)-Cu(0) bimetals, the optimized Cu(0)-Co2C interfacial catalyst achieves a remarkable leap in C2+ hydrocarbon selectivity from ∼1% to ∼60% while maintaining robust catalytic activity. It delivers a record C2+ yield of 19.4 mmol g-1Co2C h-1 at 300 °C and 3 MPa, outperforming the K-Co2C reference catalyst by a factor of 2.5. The Cu(0)-Co2C interface primarily promotes the CO*-mediated reaction pathways and effectively enhances CH2* coupling. Our findings systematically unravel the dynamic reconstruction mechanisms and interfacial synergy in Co-Cu catalysts, establishing a rational methodology for designing in situ-evolved metal-carbide interfaces to advance CO2 valorization technologies.

This work investigated a series of metal dual-atom-modified g-C3N4 catalysts (CuM/g-C3N4, M = Mn, Fe, Co, Ni, Cu, Pd, In, Sn, Pt, and Bi) for the photoreduction of CO2 to C2 chemicals by density functional theory (DFT) calculations. It was found that CuPd/g-C3N4 has the best catalytic activity and selectivity for ethanol production, with *CO-*CO2 → *CO-*COOH as the energy-determining step which has a limiting free energy change (ΔGL) of 0.43 eV. CuSn/g-C3N4 has the best activity for ethylene generation, and the energy-determining step is *CHO-*CO → *CHOH-*CO, with a ΔGL of 0.68 eV. The adsorption free energies of key species such as *CO2 and *CO-*CO2 were identified as suitable descriptors to correlate the activity of CuM/g-C3N4 catalysts for CO2 reduction to ethanol. The activity of CO2 reduction to ethylene mainly depends on the desorption free energy of ethylene, and the CuSn/g-C3N4 catalyst was screened as a promising candidate for ethylene generation. This work reveals that the catalytic activity and product selectivity of CO2 photoreduction can be effectively regulated by carefully adjusting the composition of metal dual-atom active centers and their interactions with the g-C3N4 support, providing useful reference for future catalyst design.

Cobalt-based catalysts have recently emerged as a promising frontier in propane dehydrogenation (PDH) research. Despite their potential, achieving selective suppression of nonselective metallic cobalt (Co0) species remains a critical challenge. In this work, we report a hollow zeolite architecture (Co@S-1-Hol) that effectively addresses this dilemma through spatial confinement engineering. Through depth-profiling XPS analysis complemented by H2-TPR and UV-vis spectroscopy characterization, we demonstrate a unique cobalt valence distribution where metallic Co0 species are preferentially encapsulated within hollow cavities, while Co2+ ions remain atomically dispersed in the zeolite shell matrix. DFT calculations coupled with kinetic studies reveal that the cavity-confined Co0 clusters serve as the predominant active centers for C-H bond activation. Notably, STEM-EDS mapping and TGA uncover a self-regulating mechanism: the hierarchical hollow structure facilitates rapid and selective coking on nonselective surface sites during initial reaction phases, effectively passivating undesirable side reactions while preserving intrinsic catalytic activity. This spatial engineering strategy endows the Co@S-1-Hol catalyst with superior PDH performance compared to the conventional impregnated Co/S-1 catalyst, exhibiting an enhanced C3H6 formation rate (21.6 mmol gcat -1 h-1, equivalent to 1330 mmol gCo -1 h-1) coupled with a significantly reduced deactivation rate. Under optimized conditions at 550 degrees C, the catalyst achieves 35% propane conversion with 95% propylene selectivity, representing state-of-the-art performance among reported cobalt-based PDH catalysts. This work not only provides fundamental insights into cobalt active site engineering but also establishes a paradigm for designing spatially modulated zeolite catalysts in alkane dehydrogenation applications.

In this work, density functional theory (DFT) calculations were conducted to investigate a series of metal node-modified Ti-MOF catalysts using transition metals (Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Hf, Ta, W, Os, Ir, and Au) introduced into Ti-ATA (ATA = 2-aminoterephthalic acid) for the photocatalytic reduction of CO2 to C2 products. CO2 can be sufficiently activated on Ti(M)-ATA but the adsorption configuration depends on the nature of M. Over Ti(Nb)-ATA, Ti(Ta)-ATA, Ti(Zr)-ATA and Ti(Hf)-ATA, the two *CHO species undergo C-C coupling to form *CHOCHO, an important C2 intermediate. Ti(Nb)-ATA and Ti(Ta)-ATA tend to generate ethanol, while Ti(Zr)-ATA and Ti(Hf)-ATA are more selective to ethylene. Among the Ti(M)-ATA candidates studied, Ti(Nb)-ATA was identified as the most active catalyst for CO2 reduction to ethanol due to its smallest limiting free energy change (1.12 eV), over which the *CH2CH2O reduction to *CH2CH2OH was found to be the rate-determining step. The correlation curve analysis illustrates that the reduction activity of Ti(M)-ATA catalysts is highly dependent on the binding strength of CO2 and key reaction intermediates such as *OCHOH. The analysis of electronic and optical properties indicates that the altered energy band structure and charge transfer behavior around the bimetallic nodes of Ti(Nb)-ATA account for its excellent catalytic activity for CO2 reduction to ethanol.

In this work, the reaction mechanism of ethylene glycol (EG) synthesis from the oxidation hydration of ethylene catalyzed by Al/TS-1 was studied by density functional theory calculations, based on which the optimal energy pathway, rate-limiting step, and the underlying effect of Al addition and location were identified. The calculation results showed that the introduction of Al increased the catalytic activity of the Ti(IV) site of TS-1. The relative position of Al to Ti had an obvious influence on the reaction properties over the Ti(IV) site but had a minor effect on the catalytic activity of the Al(H) Br & oslash;nsted acid site toward EG generation. In the optimal energy pathway of ethylene oxidation hydration to EG over Al/TS-1, the H2O2 activation and ethylene epoxidation occurred at the Ti(IV) site with barriers of 0.85 and 0.54 eV, respectively, while the hydration of EO to EG preferentially took place at the Al(H) Br & oslash;nsted acid site with a barrier of 1.33 eV, exhibiting bifunctional actions of Ti-Al(H) sites. The Al/TS-1 catalyst showed a high selectivity to the EG product with the formation of the diethylene glycol byproduct suppressed by slow kinetics.

This study performed DFT calculations to provide fundamental insights into the reaction mechanism of propane dehydrogenation and aromatization over Zn/P-ZSM-5 and elucidated the important roles of CO2 and P in enhancing the reaction performance and catalyst stability. The rate-limiting steps for propane dehydrogenation and propene aromatization in the optimal energy pathways were identified, with energy barriers of 1.60 and 1.44 eV, respectively. The presence of CO2 introduced new and more facile dehydrogenation routes, thereby lowering the barriers of the rate-limiting steps and facilitating the reaction. Besides, CO2 could consume carbon deposits via the reverse Boudouard reaction, which is beneficial for extending the catalyst life. The addition of P to Zn/ZSM-5 improved the stability of active sites by strengthening their resistance towards water, enhanced the interactions between the catalyst and reactants, and induced electron transfer and charge redistribution at Zn-Lewis sites by creating new non-framework O sites, thus altering the oxidation state and acidity of the Zn-Lewis sites. The synergistic promotional effects of CO2 and P offer a promising strategy for designing efficient zeolite-based catalysts for the dehydrogenation and aromatization of light alkanes.

Due to the complex internal structure of titanium silicalite-1 (TS-1), the active sites and mechanistic details of catalytic reactions using TS-1-based catalysts have not been well understood. In this work, density functional theory (DFT) calculations were conducted to provide fundamental insights into the reaction mechanism of oxidation-hydration of ethylene toward ethylene glycol production over the TS-1 catalyst model with perfect titanium(IV) active sites and the Al/TS-1 model with both Bronsted acid and titanium(IV) sites. The computational results revealed that the introduction of Al into TS-1 altered the reaction pathway, facilitated the H2O2 activation, and significantly reduced the energy barrier of the rate-limiting step for ethylene glycol generation, demonstrating a synergistic action of Ti-Al(H) sites. Over Al/TS-1, the titanium(IV) site participated in the ethylene epoxidation, while the Bronsted acid site was responsible for the hydration of ethylene oxide to ethylene glycol. The new insights into the catalytic mechanism and the identified role of bifunctional active sites offer a useful reference for the future design of Al/TS-1 catalysts with tailored catalytic performance for this important reaction.

Thermocatalytic CO2 hydrogenation to liquid fuels, including ethanol and liquid hydrocarbons, has drawn global attention recently as a potential strategy to decrease CO2 emissions and reduce the consumption of and dependence on fossil fuels. The nature of catalyst has an important impact on the conversion and selectivity and clarifying the catalyst structure-performance relationship is essential to synthesize the desired liquid products. Compared with C1 products, the generation of ethanol and liquid hydrocarbons with two or more carbon atoms is more difficult owing to the high energy barrier for C–C coupling. Current studies show that the interfacial catalysts are suitable for CO2 hydrogenation to ethanol and the active interface is generally responsible for key CO* insertion, while the metal/carbide catalysts and oxide-zeolite tandem catalysts play vital roles in that to liquid hydrocarbons. In this chapter, we discuss the latest advances in the representative noble metals, transition metals and their carbides, and modified Cu-based catalysts for the synthesis of ethanol, Fe–, Co-based catalysts as well as tandem catalysts for that of long-chain hydrocarbons. Fundamental understanding on active sites, structural evolution, CO2 activation, and reaction mechanism are discussed based on computational and experimental results. On this basis, we discuss some concepts on catalyst design as well as the challenges and opportunities for its development and potential industrial applications.

AbstractMulticomponent oxides are intriguing materials in heterogeneous catalysis, and the interface between various components often plays an essential role in oxidations. However, the underlying principles of how the hetero-interface affects the catalytic process remain largely unexplored. Here we report a unique structure design of MnCoOx catalysts by chemical reduction, specifically for ethane oxidation. Part of the Mn ions incorporates with Co oxides to form spinel MnxCo3-xO4, while the rests stay as MnO2 domains to create the MnO2-MnxCo3-xO4 interface. MnCoOx with Mn/Co ratio of 0.5 exhibits an excellent activity and stability up to 1000 h under humid conditions. The synergistic effects between MnO2 and MnxCo3-xO4 are elucidated, in which the C2H6 tends to be adsorbed on the interfacial Co sites and subsequently break the C-H bonds on the reactive lattice O of MnO2 layer. Findings from this study provide valuable insights for the rational design of efficient catalysts for alkane combustion.

This work studies the reaction mechanism and the role of CO2 2 in ethane dehydrogenation to ethene over two types of Pt-Zn/ZSM-5 catalysts. The calculation results demonstrate that the Pt-Zn sites have different roles, and Zn6Pt1/ZSM-5 6 Pt 1 /ZSM-5 is more active than Pt3Zn1/ZSM-5 3 Zn 1 /ZSM-5 due to more efficient Pt-Zn sites for dehydrogenation with the assistance of framework O of ZSM-5. CO2 2 reacts with H- species generated from ethane dehydrogenation and creates new and facile H-consuming routes, thus promoting the reaction. The positive effect of CO2 2 is more significant over Zn6Pt1/ZSM-5 6 Pt 1 /ZSM-5 than Pt3Zn1/ZSM-5 3 Zn 1 /ZSM-5 owing to the largely reduced barrier of rate-limiting step. Zn6Pt1/ZSM-5 6 Pt 1 /ZSM-5 greatly suppresses the competitive side reaction of CO2 2 with ethyl species, thus becoming a promising catalyst for ethene generation. This work deepens the mechanistic understanding of CO2-assisted 2-assisted dehydrogenation of light alkanes over Pt-Zn/ZSM-5 catalysts and unravels the important role of CO2, 2 , providing a useful reference for future catalyst design.

Catalytic COx (CO and CO2) hydrogenation to valued chemicals is one of the promising approaches to address challenges in energy, environment, and climate change. H2O is an inevitable side product in these reactions, where its existence and effect are often ignored. In fact, H2O significantly influences the catalytic active centers, reaction mechanism, and catalytic performance, preventing us from a definitive and deep understanding on the structure-performance relationship of the authentic catalysts. It is necessary, although challenging, to clarify its effect and provide practical strategies to tune the concentration and distribution of H2O to optimize its influence. In this review, we focus on how H2O in COx hydrogenation induces the structural evolution of catalysts and assists in the catalytic processes, as well as efforts to understand the underlying mechanism. We summarize and discuss some representative tuning strategies for realizing the rapid removal or local enrichment of H2O around the catalysts, along with brief techno-economic analysis and life cycle assessment. These fundamental understandings and strategies are further extended to the reactions of CO and CO2 reduction under an external field (light, electricity, and plasma). We also present suggestions and prospects for deciphering and controlling the effect of H2O in practical applications.

Unraveling the structure-activity relationship and improving the catalytic performance is paramount in propane dehydro-aromatization reactions. Herein, a tandem catalyst with high propane dehydro-aromatization reaction performance was prepared via coupling the PtFe@S-1 with Zn/ZSM-5 zeolites (PtFe@S-1&1.0Zn/ZSM-5), which exhibits high dehydrogenation activity, aromatics selectivity (~60% at ~78% propane conversion), and stability. The addition of zinc inhibits the cleavage of C6= intermediates on ZSM-5 and promotes the aromatization pathway by weakening zeolite acid strength, significantly improving the selectivity to aromatics. This understanding of the structure-activity relationship in propane dehydro-aromatization reaction helps develop future high-performance catalysts.