Search Results (291)

Dry reforming of methane (DRM) enables the simultaneous conversion of CH₄ and CO₂, yet rapid coking severely restricts the stability of Ni-based catalysts. In this study, Co was incorporated into Ce-, La-, and Zr-promoted Ni catalysts to construct Ni-Co alloy active sites, and their catalytic behavior was systematically evaluated. While single-promoter modification partially suppressed coke deposition at the expense of activity, Ni-Co alloy formation maintained high reforming performance and significantly enhanced stable catalytic performance within the 20 h evaluation period, with the Ce-promoted Ni-Co catalyst exhibiting the most durable anti-coking performance. CO₂-TPD and coke characterization results indicate that promoter species enhance medium-strength basicity and oxygen mobility, thereby facilitating CO₂ adsorption and accelerating the oxidation of surface coke intermediates; in particular, Ce supplies mobile active oxygen species through its oxygen storage-release capacity. DFT calculations further reveal that Co incorporation modulates the electronic structure of Ni sites, optimizing the balance between CH₄ dissociation and CO₂ activation and thus suppressing excessive methane cracking. These findings elucidate the synergistic effect of Ni-Co alloying and promoter modification in DRM and provide mechanistic insight for the rational design of coke-resistant Ni-based catalysts. Full article

Amid growing pressure to reduce carbon emissions, carbon capture, utilization, and storage (CCUS) has become an important pathway toward deep decarbonization. However, the conventional separated “capture–release–conversion” process suffers from high energy consumption and system complexity, which severely limits its large-scale application. Integrated CO₂ Capture and Utilization (ICCU), which enables the capture, activation, and conversion of CO₂ within a single system, has attracted widespread attention because it can effectively reduce intermediate energy-intensive steps and improve carbon utilization efficiency. This review systematically summarizes recent progress in ICCU technology, with particular emphasis on reaction mechanisms and interfacial coupling characteristics. The performance features of solvent-based chemical absorption and solid-sorbent adsorption, two widely studied capture routes, are summarized, and typical integrated conversion pathways, including reverse water–gas shift, methanation, and dry reforming of methane, are discussed. On this basis, the roles of non-conventional energy-assisted strategies, such as photocatalysis, electrocatalysis, non-thermal plasma, and microwave irradiation, in expanding ICCU systems are further examined, together with their system-level coupling potential in carbon-intensive industries such as steel, cement, and power generation. Finally, the key scientific issues and engineering challenges currently facing ICCU are analyzed from the perspectives of fundamental mechanisms, material design, and system engineering, and future development directions are proposed. This review highlights that elucidating multiscale synergistic mechanisms, developing high-performance dual-function materials, and optimizing system integration are crucial to promoting the industrial application of ICCU technology. Full article

Dry reforming of methane (DRM) is an attractive route for H₂ production and simultaneous CO₂ utilization, but its practical implementation is limited by catalyst deactivation. This study experimentally investigates the catalytic performance of Ni/Al₂O₃ and Gd-doped ceria-promoted Ni/GDC–Al₂O₃ catalysts for DRM in a fixed-bed quartz reactor over 400–800 °C at gas residence times of 0.1 s and 0.4 s. Increasing temperature and residence time enhanced CH₄ and CO₂ conversion as well as H₂ and CO yields for both catalysts. The GDC-promoted catalyst exhibited markedly improved activity, achieving conversions and product yields at 0.1 s comparable to those of Ni/Al₂O₃ at 0.4 s and reaching complete CH₄ conversion at about 650 °C, approximately 100 °C lower than the Ni/Al₂O₃ catalyst. Long-term testing at 650 °C showed stable catalytic behavior of the Ni/GDC–Al₂O₃ catalyst, while operational observations qualitatively suggested the absence of significant carbon deposition, consistent with equilibrium calculations. Full article

Tri-reforming of methane (TRM) has emerged as a promising pathway for low-carbon syngas production by integrating steam reforming, dry reforming, and partial oxidation within a single process. This coupling enables simultaneous CH₄ utilization and CO₂ valorization while enabling internal heat generation and flexible adjustment of the H₂/CO ratio for downstream synthesis. However, TRM performance cannot be adequately evaluated using conversion or energy efficiency alone, because the process involves complex interactions among competing reaction pathways, transport phenomena, catalyst stability, and thermodynamic irreversibility. This review provides a multiscale critical assessment of TRM from both first-law energy and second-law exergy perspectives, linking reaction-network fundamentals to reactor-level behavior and system-level performance. The literature evidence shows that although high temperatures and near-autothermal operation can enhance CH₄ conversion and reduce external heat demand, these conditions may simultaneously intensify deep oxidation, hotspot formation, carbon-forming tendencies, and exergy destruction. While equilibrium analyses help define feasible operating windows, they are insufficient without kinetic modeling and reactor-scale studies that capture spatial non-uniformities and pathway competition. Across reported TRM systems, exergy destruction is consistently concentrated within the reformer, identifying the reacting core as the dominant thermodynamic bottleneck. Accordingly, the key challenge in TRM is not simply to maximize conversion but to preserve chemical work potential while maintaining syngas quality and operational stability. Viewed from this perspective, TRM is better understood as an irreversibility-aware multiscale design problem in which optimal performance depends on the integrated optimization of catalyst functionality, reactor architecture, heat management, and system-level operation. Full article

The use of waste eggshell as a support material for nickel catalysts in the dry reforming of methane (DRM) aims to enhance hydrogen production while controlling catalyst deactivation caused by carbon deposition. Catalyst samples were prepared by wet impregnation and characterized by N₂ adsorption–desorption measurements, X-ray diffractometry (XRD), thermogravimetric analysis (TGA), temperature-programmed reduction, desorption of CO₂ and oxidation (H₂-TPR, CO₂-TPD and TPO), and scanning electron microscopy (SEM). Catalyst activity experiments were conducted at temperatures ranging from 500 to 750 °C, with both reduced and unreduced samples, utilizing a 1.5:1 mixture of CH₄ and CO₂ in a fixed-bed reactor, accompanied by online gas chromatography for analysis. By employing a low calcination temperature (500 °C), the integrity of the eggshell support was maintained. The Ni20 catalyst, with an intermediate nickel loading, exhibited the highest CH₄ (24.5%) and CO₂ (60.5%) conversion and showed minimal carbon formation. Notably, the basicity of the eggshell support contributed to the suppression of carbon deposition, as evidenced by the TPO and SEM analyses. The results suggest that the inherent basicity of the eggshell enhances catalyst resistance to coking while also contributing to the mitigation of eggshell waste. Full article

This study investigates the influence of isomorphous substitution of Aluminum by V, Zr, La, and Ni in Beta zeolite frameworks used as supports for Ni-based dry reforming of methane catalysts. The research focuses on how the nature of the incorporated metal affects catalytic activity and long-term stability. Catalysts were synthesized using both co-impregnation and sequential impregnation strategies. Physicochemical characterization—including gas adsorption, X-ray diffraction, transmission electron microscopy, and H₂ temperature-programmed reduction—revealed distinct structural roles for each metal. Results indicate that V primarily occupies T-vacancy sites within the dealuminated Beta framework, whereas Ni resides as charge-compensating extra-framework species or highly dispersed NiO clusters. Zr and La tend to form highly dispersed oxide species or occupy enlarged silanol nests. Notably, the addition of La₂O₃ was found to significantly enhance the long-term stability of the catalysts during the dry reforming of methane process. V-modified catalysts exhibited the highest activity but suffered from low stability; conversely, Zr incorporation offered the best overall performance, balancing high activity with enhanced stability, achieving 85% CO₂ and 75% CH₄ conversion, with no detectable carbon deposition after 98 h on stream. Full article

Dry reforming of methane (DRM) is a key reaction for syngas production and greenhouse gas utilisation, involving multiple interacting operating variables. In this work, an interpretable machine learning approach based on CatBoost regression coupled with SHapley Additive exPlanations (SHAP) is applied to a previously published DRM dataset to analyse the influence of reaction temperature, CH₄/CO₂ feed ratio, and Ni loading on CH₄ and CO₂ conversions and H₂ and CO yields. The objective of this study is methodological rather than experimental, focusing on the use of interpretable machine learning to extract variable importance hierarchies and conditional interaction effects from data-limited DRM studies. The analysis confirms that reaction temperature is the dominant controlling parameter, while feed ratio and Ni loading exhibit secondary, regime-dependent influences. No new catalytic mechanisms or experimental findings are proposed. The results illustrate how CatBoost–SHAP analysis can complement experimental DRM research by providing transparent, quantitative interpretation of published datasets under realistic data constraints. These findings are consistent with established DRM thermodynamic and kinetic behaviour, where temperature governs endothermic reforming reactions, while feed composition and metal loading influence carbon formation pathways and catalytic activity. Full article

Dry reforming of methane (DRM) converts the greenhouse gases methane (CH₄) and carbon dioxide (CO₂) into syngas (hydrogen (H₂) and carbon monoxide (CO)). Despite its numerous advantages, DRM has not yet been industrialized due to catalyst deactivation and competing side reactions. While Ni-based catalysts have been widely used, they are prone to increased carbon deposition and sintering, and although bimetallic systems and oxygen-based supports have shown promise, their effects on carbon deposition are yet to be fully understood. In this study, carbon nanotube (CNT)-supported Pt-Ni catalysts incorporating mixed oxides of CeZrO₂ and CeZrLaO₂ were investigated to evaluate the impact of support composition and metal–support interactions in DRM. The catalysts were synthesized and subsequently tested in DRM. Catalysts supported on CNTs displayed higher CH₄ and CO₂ conversions compared to conventional ceria–zirconia, highlighting the beneficial role of the carbon nanotube support in improving dispersion and accessibility of the metal active sites. Addition of Pt was found to promote reverse water–gas shift (RWGS) reaction, whereas the addition of La was found to decrease catalytic activity. Despite the formation of a Ni-Pt alloy, the obtained catalysts favored RWGS over DRM. These findings illustrate key limitations and design considerations for optimization of CNT-supported bimetallic catalysts in DRM. Full article

Oxidative dry reforming of methane (ODRM) in a membrane reactor can become the basis for creating an energy-efficient process for converting greenhouse gases into a sought-after chemical raw material for gas chemistry. The process was carried out in a distribution mode in a reactor with a membrane porous catalyst (MPC) at a temperature of 850 °C. The reagents CH₄ and CO₂ were supplied to the MPC through a volume of retentate, and O₂ mixed with N₂ through a volume of permeate. The mixture of reaction products was removed from the shell side. In the experiment, the effect of the O₂/CO₂ ratio on the conversion of CH₄, CO₂ and O₂, as well as on the thermal effect of the process, was established. When oxygen enters the reactor during dry reforming of methane (DRM), the temperature inversion in the volumes of retentate and permeate occurs, as well as a decrease in electricity consumption in the resistor furnace. The observed effects of the ODRM process in MPC were interpreted using the hypothesis of active mass transfer occurring in pore channels. It is assumed that part of the carbon deposits in MPC will be gasified by oxygen. Full article

This study evaluates the performance of Ni-La₂O₃/Beta catalysts for the dry reforming of methane, focusing on the effects of nickel loading, catalyst pretreatment, reaction temperature, and gas composition and flow rate. Catalysts with nickel contents ranging from 3 to 20 percent by weight were prepared via wet impregnation and characterized by gas adsorption, X-ray diffraction, temperature-programmed reduction with hydrogen, thermogravimetric analysis, and transmission electron microscopy. The results indicate that nickel gradually incorporates into the zeolitic support, preferentially occupying the most stable sites. Direct reduction of the impregnated catalyst precursors—omitting the calcination step—yielded materials with slightly higher methane conversion (ca. 3.5%) and enhanced stability. This improved performance is attributed to the reduction occurring during the thermal decomposition of supported nickel nitrate, which promotes finer nickel dispersion and stronger interaction with the La₂O₃-modified Beta zeolite. Full article

Power-to-X technologies play a crucial role in accelerating the energy and material transition. A key opportunity lies in integrating these systems with existing bio-based infrastructures such as anaerobic digesters, providing a reliable source of biogenic carbon. Developing effective Power-to-Methanol (PtM) pathways requires a comprehensive understanding of process behavior through detailed simulation, including technical performance, economic feasibility, and environmental consequences. Despite growing interest, substantial variation remains in published levelized methanol costs, and many assessments insufficiently account for the full environmental footprint of production routes. This study evaluates the potential of PtM deployment in the Netherlands by comparing two pathways that utilize biogenic carbon sources: (i) hydrogenation of captured CO₂ using green hydrogen and (ii) dry methane reforming (DMR) of biogas, followed by catalytic syngas conversion to methanol. Results indicate that operational expenses—mainly driven by renewable electricity consumption—far outweigh capital investment. Both routes yield an LCoMeOH of approximately €2630 per tonne, about five times the cost of fossil-based methanol. Life cycle analysis shows that DMR performs more favorably overall, although elevated freshwater ecotoxicity and eutrophication result from digestate application as fertilizer. Continued improvements in renewable energy integration and nutrient recovery technologies are essential for enhancing future economic and environmental performance. Full article

Driven by the growing global energy demand and the pursuit of carbon utilization goals, dry reforming of methane (DRM) has attracted considerable attention for its ability to convert CO₂ and CH₄ into syngas. Biogas, an eco-friendly product of processes such as anaerobic digestion, is primarily composed of CO₂ and CH₄ and ideally meets the feedstock requirements for DRM. In practice, biogas is generated via anaerobic digestion of livestock manure and other organic waste, providing a stable and sustainable source for the DRM reaction and thus enabling waste valorization. Supported Ni⁰ catalysts have become a research focus in this field due to their high catalytic activity and moderate cost. Conventional particulate Ni⁰ catalysts, however, are prone to carbon coking in fixed-bed applications and are difficult to effectively recover and regenerate after the reaction; thus, they are often being discarded, leading to resource waste and environmental burden. To address these issues, this study has designed a novel metal-sintered fleece catalyst support and developed a corresponding reactor. The effects of the catalyst preparation method, activation conditions, and the support structure on DRM performance have been systematically investigated. The spent Ni-based catalyst could be regenerated via calcination to restore catalytic activity and enable multiple cycles of use, significantly extending the catalyst’s lifespan and offering both economic and environmental benefits. Experimental results have demonstrated that the reactor achieved a conversion rate exceeding 80% with near-complete product selectivity. Full article

Nickel-supported catalysts over SiO₂-CeO₂ mixed oxides were investigated as catalysts for syngas production via dry reforming of methane. SiO₂-CeO₂ supports were optimized by varying the preparation method and ceria loading with the aim of stabilizing nickel nanoparticles, enhancing the catalytic performance, and improving the resistance to coke formation under high-temperature reforming conditions. To investigate the effect of support composition, SiO₂-CeO₂ mixed oxides with ceria contents ranging from 5 to 30 wt% were prepared using two synthesis routes: sol–gel and wetness impregnation methods. A nickel loading of 5 wt% was deposited on the resulting supports. The catalysts were characterized by XRD, N₂ physisorption, temperature-programmed reduction (TPR), and Raman spectroscopy. Catalytic activity tests were carried out over reduced catalysts in an H₂-He stream at 750 °C, using a feed mixture containing 15 vol% CH₄ and 15 vol% CO₂ in He. The effect of temperature on catalytic performance was evaluated in the range of 450–750 °C. Thermogravimetric, XRD and Raman analyses of spent catalysts were used to assess carbon deposition and the nature of crystalline phases. The results highlight the role of CeO₂ content and preparation method in determining nickel dispersion, reducibility, catalytic performance in DRM, and coke resistance. Full article

In this work, a rational catalyst design based on interfacial architecture engineering is proposed for low-temperature dry methane reforming (DMR) at 550 °C. Ni-based catalysts containing 10 wt% Ni were developed on a γ-Al₂O₃ support modified with 9 wt% MgO–1 wt% ZrO₂. Zirconia promoters were introduced either by dry impregnation or via an ammonia vapor-assisted route to construct a Ni–NiO–ZrO₂ interfacial network. The effects of ZrO₂ content (0, 1, and 3 wt%) and synthesis route on metal–support interactions, oxygen mobility, and coke resistance were systematically investigated. ZrO₂ promotion increased the fraction of reducible Ni species and preferentially enhanced CO₂ activation, thereby promoting the reverse water–gas shift (RWGS) reaction and lowering the H₂/CO ratio. In contrast, ammonia vapor-assisted preparation induced the formation of an LDH-derived Ni–NiO–ZrO₂ surface network, which increased the concentration of surface-accessible Ni species, suppressed excessive zirconia coverage, and significantly improved apparent oxygen mobility. These synergistic structural features are consistent with enhanced oxygen-assisted carbon removal and improved coke management through regulation of the nature of carbon species, leading to more balanced activation of CH₄ and CO₂. Overall, this study provides insights into interfacial structure–performance relationships for designing efficient Ni-based catalysts for CO₂ utilization. Full article

This study pioneers the application of an induction heating fluidized bed (IH-FB) to dry methane reforming (DRM), establishing an efficient novel process for CO₂ utilization. Synergistic induction heating is achieved by utilizing eddy-current loss heating in a carbon steel rod for indirect heat transfer to particles and gases, coupled with hysteresis loss heating in magnetic Ni- and Co-based catalyst bed materials for direct induction heating. The system achieved an overall bed heating rate of 200 °C/min under fluidized conditions. DRM tests show that the IH-FB initiates catalytic reactions at a relatively low temperature of 400 °C, converting CH₄ and CO₂ into syngas (CO and H₂). Co-based catalysts exhibited higher feedstock conversion and enhanced stability compared to Ni-based catalysts owing to their greater hysteresis heating capacity and broader ferromagnetic temperature range, achieving 89.69% CH4 and 83.37% CO₂ conversions at 700 °C. Throughout the tested temperature range (400–700 °C), the IH-FB outperformed the resistance heating fluidized bed (RH-FB) in feedstock conversion, primarily due to its rapid thermal response, particle self-heating, and enhanced heat and mass transfer advantages from fluidization. At equivalent target conversion rates, the IH-FB significantly reduced the operating temperature compared to the RH-FB, demonstrating superior energy-saving benefits. This study demonstrated a promising route for efficient CO₂ utilization via DRM. Full article