Dry Reforming Of Methane Reaction Research Articles

Role of Active Site and CO2-Interacting Surface Species in Dry Reforming of Methane over Strontium Promoted Ni Catalyst Supported by Lanthanum-Zirconia.

In the context of global warming, the dry reforming of methane (DRM) has gained significant attention due to its ability to simultaneously deplete two greenhouse gases, i. e. CH4 and CO2, and generate syngas. Herein, strontium-promoted Lanthanum-zirconia supported Ni catalysts are investigated for DRM and characterized by X-ray diffraction, surface area and porosity, FTIR-RAMAN spectroscopy, and temperature-programmed experiments. The Ni/LaZr catalyst contains formate and oxycarbonate-like CO2-interacting species, while strontium-promoted catalysts have additional ionic CO3 2- species. The current catalyst system of 2 % strontium-promoted Ni/LaZr has active sites derived from three types of NiO: easily reducible, moderately interacted, and strongly interacted. During the DRM reaction over the current system, CO2 is a better oxidant than O2 for removing carbon deposits. Additionally, the catalysts attain higher reducibility under oxidizing gas (CO2) and reducing gas (H2) during the DRM reaction. For optimal hydrogen yield of approximately 60 % within 420 minutes of operation over Ni2Sr/LaZr catalyst, a balance between the population of active site Ni and CO2-interacting surface species is necessary.

Dry Reforming of Methane on Low‐Loading Rh Catalysts

Dry reforming of methane (DRM) is a promising catalytic process for converting greenhouse gases (CH4 and CO2) into syngas (CO and H2). This study investigates DRM under moderate conditions (550 °C) using supported ultra‐low loading (0.05 wt%) metal (M) catalysts (M = Rh, Ru, Pt, Pd, Ir, Au, and Ni). The reaction was carried out for 6 h with a flow rate of 30 mL/min for both CH4 and CO2, using 0.10 g of catalyst. Among these catalysts, 0.05 wt% Rh/Al2O3 exhibited the highest DRM activity. The effect of catalyst supports revealed that Al2O3 is the most effective support for 0.05 wt% Rh. The DRM activity of Rh species supported on Al2O3 and SiO2 was compared, and the Rh species on Al2O3 outperformed those on SiO2, indicating Al2O3 enhances the DRM activity of Rh. When comparing the DRM activity of Rh nanoparticles and Rh single atoms, it was suggested that Rh nanoparticles might exhibit superior performance for DRM. Coke deposited on 0.05 wt% Rh/Al2O3 is removed by CO2, maintaining stable catalytic activity. These findings provide valuable insights into the design of catalysts that minimize the use of noble metals in DRM reactions.

Boosting Dry Reforming of Methane Over NiCo/CeO2 Catalysts Treated by Hydrogen Plasma

ABSTRACTNickel (Ni)‐based catalysts are prospective materials for dry reforming of methane (DRM) reaction, but suffer from coke formation and limited activity for CO2 conversion. To improve the reactivity of Ni‐based catalysts, a promising strategy is introducing cobalt (Co) metal. Here, we construct highly efficient NiCo sites on CeO2 support by H2 plasma, which enables the catalyst to obtain a remarkable increase in DRM reaction than the samples treated by conventional H2 reduction. H2 plasma treatment results in the formation of highly dispersed NiCo alloy nanoparticles and high‐concentration oxygen vacancy. These features create large numbers of highly active sites to boost the activation of CH4 and especially CO2 and their catalytic reactions, resulting in strong coke resistance in the DRM reaction.

Physical and chemical characteristics and activity of nickel-modified cobalt-iron-containing catalysts in the reaction of dry reforming of methane

In the process of dry reforming of methane (DRM), the activity of low-percentage catalysts based on cobalt and iron oxides and their modification with nickel oxide was studied. It has been established that the addition of nickel oxide into the Fe2O3/γ-Al2O3 catalyst increases the degree of methane conversion from 14 to 89%, and also increases the yield of target reaction products H2 to 43.0 vol.%, CO to 46.1 vol.% at 850 °C. On a Co3О4-NiО/γ-Al2O3 catalyst at 850 °C, methane conversion reaches to 88.1%, the yield of H2 and CO is 44.8%. TPR-H2 analyzes showed that the introduction of nickel oxide into Fe2O3/γ-Al2O3 composition, in contrast to the Co3O4/γ-Al2O3 catalyst, the temperature peaks of Fe2O3-NiО/γ-Al2O3, reduction shift towards lower temperatures and weaken the interaction of metals with the support - γ-Al2O3 and thereby the amount of active reduced particles of iron and nickel oxides increases, which ensures good catalytic activity of Fe2O3-NiО/γ-Al2O3. According to the XRD results, spinel-like form - NiFe2O4, NiAl2O4 and CoAl2O4, also phase as Fe2O3 were obtained on the Fe2O3-NiО/γ-Al2O3 catalyst. This indicates that the developed catalysts form new phases that are active at high temperatures to produce synthesis gas in reduction-oxidation processes during the DRM reaction.

Dry Reforming of Methane (DRM) over Hydrotalcite-Based Ni-Ga/(Mg, Al)Ox Catalysts: Tailoring Ga Content for Improved Stability

Dry reforming of methane (DRM) is a promising way to convert methane and carbon dioxide into syngas, which can be further utilized to synthesize value-added chemicals. One of the main challenges for the DRM process is finding catalysts that are highly active and stable. This study explores the potential use of Ni-based catalysts modified by Ga. Different Ni-Ga/(Mg, Al)Ox catalysts, with various Ga/Ni molar ratios (0, 0.1, 0.3, 0.5, and 1), were synthesized by the co-precipitation method. The catalysts were tested for the DRM reaction to evaluate their activity and stability. The Ni/(Mg, Al)Ox and its Ga-modified Ni-Ga/(Mg, Al)Ox were characterized by N2 adsorption–desorption, Fourier Transform Infrared Spectroscopy (FTIR), H2-temperature-programmed reduction (TPR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and Raman techniques. The test of catalytic activity, at 700 °C, 1 atm, GHSV of 42,000 mL/h/g, and a CH4: CO2 ratio of 1, revealed that Ga incorporation effectively enhanced the catalyst stability. Particularly, the Ni-Ga/(Mg, Al)Ox catalyst with Ga/Ni ratio of 0.3 exhibited the best catalytic performance, with CH4 and CO2 conversions of 66% and 74%, respectively, and an H2/CO ratio of 0.92. Furthermore, the CH4 and CO2 conversions increased from 34% and 46%, respectively, when testing at 600 °C, to 94% and 96% when the catalytic activity was operated at 850 °C. The best catalyst’s 20 h stream performance demonstrated its great stability. DFT analysis revealed an alteration in the electronic properties of nickel upon Ga incorporation, the d-band center of the Ga modified catalyst (Ga/Ni ratio of 0.3) shifted closer to the Fermi level, and a charge transfer from Ga to Ni atoms was observed. This research provides valuable insights into the development of Ga-modified catalysts and emphasizes their potential for efficient conversion of greenhouse gases into syngas.

Kinetic investigation of dry reforming of methane reaction over Ni–Rh/ZrO2–Al2O3 catalyst using Langmuir-Freundlich isotherm

The study involved conducting kinetic measurements for the dry reforming of methane (DRM) over a Ni–Rh/Al2O3 (85%)-ZrO2(15%) catalyst under a wide range of operating conditions (temperature: 500–900 °C, total flow rate of the inlet feed: 50–100 mL/min). The support material was prepared using the sol-gel method, followed by impregnation of Ni–Rh catalyst on the incipient wetness of the Al2O3–ZrO2 support. The calcined, reduced and spent samples were characterized by X-ray diffraction (XRD), thermal gravimetric analysis (TGA), inductively coupled plasma atomic emission spectrometer (ICP-AES), N2 adsorption/desorption and CHNS analyzer, and tested for activity, yield and stability in DRM reaction. Furthermore, kinetic behavior of Ni–Rh/Al2O3–ZrO2 catalyst in DRM process was investigated by assuming DRM and reverse water-gas shift (RWGS) reactions take place on two kinds of different active sites. Experimental data were fitted using rate expressions based on the Langmuir-Freundlich (LF) isotherm for DRM and RWGS reactions. The activation energy for the DRM reaction was optimized at 43.62 kJ/mol, falling within the reported literature range of 24.73–108.9 kJ/mol. Statistical indices indicated that the kinetic model accurately predicted CO2 conversion compared to other responses, with an error of 12.054%. The computed and experimental trends for CH4 and CO2 conversions, H2 and Co yield in terms of temperature were similar with each other and the difference between the calculated and experimental trends was lower for conversions compared to yields.

Amorphization-sparked superb activity and excellent coke-resistance of Ni nanocatalyst

Selective conversion of CH4 and CO2 to syngas via the dry reforming reaction is highly desirable in terms of restraining the greenhouse effect and meanwhile acquiring useful chemicals. However, the most promising Ni catalysts for the reaction still suffer from severe coking and thus poor durability. Here, we report that using amorphous Ni nanoparticles synthesized on an N modified mesoporous silica support, the catalytic activity and coke-resistant performance of Ni toward the photothermal dry reforming of methane (DRM) are greatly improved. Theoretical calculations further unveil that the amorphous Ni nanoparticles are much more energetically favorable to activate the CH4 and CO2 molecules as well as to remove the C* intermediates for coke formation than their crystalline Ni counterparts, which renders the amorphous Ni nanoparticles with both superb activity and excellent coke-resisting property. This finding possibly provides a new avenue to make both highly efficient and anti-coking catalysts for the DRM reaction and beyond via facile amorphization of active metals.

Reforming of methane over two-dimensional Mo2C-Ni/γ-Al2O3 catalyst

The impact of two-dimensional Mo2C (2D-Mo2C) on the activity and stability of a Ni/γ-Al2O3 catalyst for the dry reforming of methane (DRM) is reported. 1.1 wt% 2D-Mo2C added to 13 wt% Ni/γ-Al2O3 increased activity by ∼40 %. Characterization results showed an interaction between 2D-Mo2C and Ni that resulted in the formation of a NixMoy bulk phase (XRD) and Ni-Mo-oxycarbide surface species (XPS). The presence of 2D-Mo2C also improved the stability of the catalyst compared to Ni/γ-Al2O3 by reducing coke deposition. H2 space-time-yields (STYs) were independent of CO2 partial pressure and were lower than the CO STYs. Power law kinetic models were consistent with a DRM reaction pathway via CH4 decomposition (MD) and the reverse Boudouard (RBD) reactions.

Effect of cobalt on the activity of nickel-based/magnesium-substituted hydroxyapatite catalysts for dry reforming of methane

The dry reforming of methane (DRM) reaction can directly convert methane (CH4) and carbon dioxide (CO2) into syngas (H2+CO), which is a promising method for achieving carbon neutralization. In this study, a series of 3Ni-xCo/Mg1HAP alloy catalysts with different ratios were synthesized by the coprecipitation method, and the optimum Ni/Co ratio for the DRM reaction was studied. A series of characterization methods revealed that after Co was added, the formation of Ni–Co alloys increased the interactions between metals. However, an excess of Co inhibits the entry of Ni into the lattice of Mg1HAP, resulting in metal accumulation on the surface of the support. In addition, the introduction of Co improves the dispersion of Ni metal, which endows the catalyst with better catalytic activity and stability. Raman spectroscopy of the catalyst after the stability test showed that the addition of Co reduced the proportion of graphitic carbon, which was also the main reason for its improved stability.

The promotion mechanisms of Mo for the dry reforming of methane reaction over a Mo-doped Ni(2 1 1) bimetallic catalyst

With the escalating severity of climate change, the DRM reaction has gained attention as an effective pathway for utilizing CO2. Enhancing reaction activity and identifying the sources of carbon deposition during the DRM reaction on Ni-based catalysts pose crucial yet challenging questions. In this study, we investigate the effects of Mo doping on the reaction activity and carbon deposition of Ni catalysts using a combined DFT and microkinetic method. In terms of the models, Mo replaced one Ni atom in the surface and subsurface layers to represent Mo in the initial stages and in prolonged on the reaction, namely NiMoU(211) and NiMoL(211). Through the analysis of electronic structure, intermediate structures, and reaction barriers compared with Ni(211), the impact of Mo doping on the surface activity and carbon deposition of Ni(211) is studied. The results indicate that the strong Ni-Mo interaction enhances intermediate stability, leading to increased reaction activity. Mo doping promotes the increase in O concentration, but at low temperatures, reaction rates decrease sharply. Furthermore, Mo doping enhances the resistance to carbon deposition on Ni(211) surfaces and improves the ability to remove carbon deposits, especially in prolonged reaction models. These findings provide new mechanistic insights into the DRM reaction on Ni(211) surfaces, which were previously well-explained by experimental results, and are valuable for understanding quantum processes.

Mechanistic study of transition metal loaded/doped Ni − MgO catalyzed dry reforming of methane: DFT calculations

In the context of carbon peaking and carbon neutrality goals, dry reforming of methane (DRM) offers both environmental and economic benefits and holds great promise for development. In this work, based on Ni loaded MgO, two structural models constructed by transition metal loading (TM+Ni − MgO, TM=Fe, Zr, Mo) and doping (Ni − TM/MgO) were used for DRM by density functional theory (DFT). And the adsorption of CO2 and CH4 on these structures was analyzed. The partial density of states (PDOS) and charge density difference (CDD) indicate that due to the presence of unfilled electron d − orbitals in the TM atoms, electron transfer occurs between them and the p − orbitals of the C and O atoms. It facilitates the interactions and enhances the adsorption between CO2 and MgO. On this basis, the DRM reactions on Fe and Ni loaded MgO (FeNi − MgO) and Ni − loaded, Fe − doped MgO (Ni − Fe/MgO) were screened for focused research. It was revealed that the addition of Fe lowered the energy barrier values for some of the elementary reaction steps, allowing the reaction to proceed more easily. And Ni − Fe/MgO showed greater advantages by possessing more stable energy barrier fluctuation intervals (ER1 − ER3) and the smallest CO2 dissociation energy barrier.

In situ DRIFTs-based comprehensive reaction mechanism of photo-thermal synergetic catalysis for dry reforming of methane over Ru-CeO2 catalyst

Solar-driven photo-thermal dry reforming of methane (DRM) is an environmentally friendly production route for high-value-added chemicals. However, the lack of thorough understanding of the mechanism for photo-thermal reaction has limited its further development. Here, we systematically investigated the mechanism of photo-thermal DRM reaction with the representative of Ru/CeO2 catalyst. Through in situ DRIFTs and transient experiments, comprehensive investigation into the reaction steps and their reactive sites in the process of DRM reaction were conducted. Besides, the excitation and migration direction of photo-electron was determined by ISI-XPS experiments, and the change of surface defect structure induced by light was characterized by ISI-EPR experiments. Based on the above results, the photo-enhancement effect on each micro-reaction step was determined. This study provides a theoretical basis for the industrialization of photo-thermal DRM reaction and its development of catalysts.

Photo-Thermal Dry Reforming of Methane with PGM-Free and PGM-Based Catalysts: A Review.

Dry reforming of methane (DRM) is considered one of the most promising technologies for efficient greenhouse gas management thanks to the fact that through this reaction, it is possible to reduce CO2 and CH4 to obtain syngas, a mixture of H2 and CO, with a suitable ratio for the Fischer-Tropsch production of long-chain hydrocarbons. Two other main processes can yield H2 from CH4, i.e., Steam Reforming of Methane (SRM) and Partial Oxidation of Methane (POM), even though, not having CO2 as a reagent, they are considered less green. Recently, scientists' challenge is to overcome the many drawbacks of DRM reactions, i.e., the use of precious metal-based catalysts, the high temperatures of the process, metal particle sintering and carbon deposition on the catalysts' surfaces. To overcome these issues, one proposed solution is to implement photo-thermal dry reforming of methane in which irradiation with light is used in combination with heating to improve the efficiency of the process. In this paper, we review the work of several groups aiming to investigate the pivotal promoting role of light radiation in DRM. Focus is also placed on the catalysts' design and the progress needed for bringing DRM to an industrial scale.

Utilization of coal gasification fine slag-derived mesoporous silica supports for enhanced dry reforming of methane catalysts

Utilizing industrial waste coal gasification fine slag (CGFS) for the preparation of dry reforming of methane (DRM) catalyst supports presents an innovative approach to waste utilization. This strategy not only addresses solid waste pollution but also reduces the production costs associated with DRM catalysts. Currently, the industrialization of the DRM reaction remains elusive. Therefore, selecting an appropriate catalyst preparation method is imperative for potential industrial applications. This study centers on the synthesis of mesoporous silica (MS) supports using coal gasification fine slag. The impact of support structure, catalyst preparation method, and active metal loading on the resistance to sintering and carbon deposition of the catalysts is explored through diverse characterization techniques. The MS support derived from coal gasification fine slag showcases a unique disordered mesoporous architecture that enhances the dispersion of the metal across the support surface. In addition, we report a MS catalyst prepared by a co-precipitation method (MS–CP), which exhibits excellent catalytic activity and stability due to its strong metal-support interaction. Results suggest that during synthesis, the MS–CP catalyst activates the inert MS support by strongly interacting with Ni metal, resulting in the formation of Ni3Si2O5(OH)4 species. The Ni–O–Si bond can activate CO2, thereby promoting the availability of interfacial oxygen during the reaction. This process accelerates the gasification of surface Cn generated by CH4 decomposition. Notably, the loading analysis indicates that MS–CP loaded with 10 wt% Ni demonstrates the highest resistance to carbon deposition and sintering. Thus, the unique strong metal-supported interactions provide a new avenue for the development of nickel-based DRM catalysts.

Influence of catalyst shape on plasma-assisted dry reforming of methane: A comparative study of Ni-CeO2 nano-cubes and nano-octahedra

This study investigated the performance of 10 wt% Ni-CeO2 nano-cubes (NC) and nano-octahedra (NO) shaped catalysts in plasma-assisted dry reforming of methane (DRM) environment to understand the influence of catalyst morphology on catalytic activity and global reaction pathway. The presence of different exposed crystal planes (i.e., (111), (110), and (100)) in the CeO2 shapes led to varied NiOx-CeO2 interactions, with the NO-shaped catalyst exhibiting a higher oxygen vacancy concentration, lattice defects, and moderate basic sites compared to the NC catalyst. This interaction in the plasma DRM environment significantly enhances conversions for both shaped catalysts, with the effect more pronounced in the case of the NO-shaped catalyst. The performance data suggest that running plasma DRM at moderate temperature and higher plasma power is relatively efficient. Increasing temperatures or plasma power diverts the DRM reaction towards more H2 production, reducing CO production for both shaped catalysts. This confirms the crucial role of the catalyst in controlling the global reaction pathway considering plasma power or temperature enhancement. Plasma interactions create additional surface defects during the DRM reaction, and defect concentration is closely linked to catalyst morphology. Carbon deposits on the catalyst surface can be readily removed via CO2 plasma regeneration treatment without affecting catalyst performance. Additionally, prolonged plasma exposure leads to NiO phase separation into concentrated Ni, suggesting a cyclical DRM and regeneration approach rather than a continuous reaction.

Bimetal (CuNi and CuCo) substituted CeO2: An approach for low temperature dry reforming of methane

The solution combustion synthesis method was used to make CuNi substituted CeO2 (7.5 at.% of Cu+7.5 at.% of Ni), and CuCo substituted CeO2 (7.5 at.% of Cu+7.5 at.% of Co) catalysts. The catalysts were characterized by x-ray diffraction (XRD),XPS, BET surface area measurements, scanning electron microscopy (SEM), and H2-temperature-programmed reduction(H2-TPR). Further, these catalysts were tested for endothermic dry reforming of methane (DRM) reaction. The CuNi substituted CeO2 catalyst started dry reforming of methane (DRM) at around 350 °C, while the CuCo substituted CeO2 catalyst started DRM at around 450 °C. This indicates that the CuNi catalyst has a lower activation temperature for the DRM reaction compared to the CuCo catalyst. The CuNi substituted CeO2 catalyst converted CH4 better than the CuCo substituted CeO2 at all temperatures reaching 98 % conversion at 800 °C The CuNi substituted CeO2 showed higher H2/CO ratio in comparison to the CuCo substituted CeO2 but the long-term stability followed the opposite order. Thermal gravimetric analysis (TGA), SEM and O2-TPO were used to quantify as well as to understand the nature of carbon that had built up on spent catalysts and it is mostly amorphous. Transient studies have shown that along with the lattice oxygen participation, controlled methane decomposition step is necessary for stability of catalysts. Transient studies also recommended additional reaction steps during DRM where an exothermic methane partial oxidation step reduces the endothermicity of DRM. Also, CO2 activation also goes via the defect dissociation route, an additional step to the conventional carbon oxidation (CO2+C→CO) step. So, novelty of this work is in elucidating the exact role of lattice oxygen in imparting the activity and stability to the DRM catalyst.

Syngas production via microwave-assisted Dry Reforming of Methane over NiFe/MgAl2O4 alloy catalyst

Dry reforming of methane (DRM) represents a promising avenue for generating syngas while simultaneously reducing CO2 emissions. However, its industrial application has been constrained by the necessity for elevated temperatures to prevent coke. Microwave (MW)-assisted DRM emerges as a compelling solution to facilitate high-temperature reactions, capitalizing on surplus renewable electrons to heat the catalyst bed swiftly and selectively, thereby circumventing the inefficient heating of the entire reactor. In this study, DRM is conducted under MW irradiation using NiFe/MgAl2O4 alloy catalysts. The impacts of MW power and catalysts' temperature-response behavior are investigated as well as the active components (Ni and Fe), and space velocity on the DRM reaction are explored. We determined the optimal quantities of Fe and Ni necessary to achieve the desired balance between MW heating and driving the DRM reaction. Under specific conditions—Ni content at 25 wt%, Fe content at 40 wt%, MW power of 286 W g−1, a temperature of 700 °C, flow rate of 450 mL min−1 and a space velocity of 12857 mL·g−1·hr−1—conversion rates of 85 % for CH4 and 62 % for CO2 are achieved. NiFe/MgAl2O4 catalysts demonstrated high potential to be used in the MW-driven DRM as compared to conventional electric heating methods.

Pulsed laser induced plasma and thermal effects on molybdenum carbide for dry reforming of methane

Dry reforming of methane (DRM) is a highly endothermic process, with its development hindered by the harsh thermocatalytic conditions required. We propose an innovative DRM approach utilizing a 16 W pulsed laser in combination with a cost-effective Mo2C catalyst, enabling DRM under milder conditions. The pulsed laser serves a dual function by inducing localized high temperatures and generating *CH plasma on the Mo2C surface. This activates CH4 and CO2, significantly accelerating the DRM reaction. Notably, the laser directly generates *CH plasma from CH4 through thermionic emission and cascade ionization, bypassing the traditional step-by-step dehydrogenation process and eliminating the rate-limiting step of methane cracking. This method maintains a carbon-oxygen balanced environment, thus preventing the deactivation of the Mo2C catalyst due to CO2 oxidation. The laser-catalytic DRM achieves high yields of H2 (14300.8 mmol h−1 g−1) and CO (14949.9 mmol h−1 g−1) with satisfactory energy efficiency (0.98 mmol kJ−1), providing a promising alternative for high-energy-consuming catalytic systems.

Dry Reforming of Methane on Ni/LaZrO2 Catalyst under External Electric Fields: A Combined First-Principles and Microkinetic Modeling Study.

Dry reforming of methane (DRM) reaction has great potential in reducing the greenhouse effect and solving energy problems. Herein, the DRM reaction mechanism and activity on Ni16/LaZrO2 catalyst under electric fields were comprehensively investigated by combining density functional theory calculations with microkinetic modeling. The results showed that La doping increases the interaction between Ni and ZrO2 by Ni cluster transfer of more electrons. The adsorption strength of species followed the order Ni16/ZrO2 > Ni16/LaZrO2, which is consistent with the results for the d-band center but opposite to the metal-support interaction. The best DRM reaction path on Ni16/LaZrO2 was the CH2-O pathway, which is different from the CH-O pathway on Ni(111) and Ni16/ZrO2. Both positive and negative electric fields of strong and weak metal-support interactions reduced the energy barrier of DRM reaction. Importantly, our results showed that the more dispersed and smaller Ni12/LaZrO2 model by considering the dispersing effect induced by La doping, which displayed very different results from that of Ni16/LaZrO2: reduced the energy barrier for methane decomposition, thereby promoting DRM reaction activity. Microkinetic results showed that the carbon deposition behavior of DRM becomes weaker on Ni16/LaZrO2 due to the suppression of methane decomposition in the presence of La doping compared to Ni16/ZrO2, but the opposite result is obtained on Ni12/LaZrO2. The order of DRM reactivity was Ni16/LaZrO2 < Ni16/ZrO2 < Ni12/LaZrO2, which is consistent with the experiment observations. The conversion of methane and CO2 was higher in positive electric fields than in negative electric fields at low temperatures, but the results were opposite at high temperature. Negative electric fields can improve the carbon deposition resistance of Ni-based catalysts compared to positive electric fields. The degree of rate control analysis showed that CHx* oxidation also plays an important role in the DRM reaction. We envision that this study could provide a deeper understanding for guiding the widespread application of electric field catalysis.

Insight into the Dynamic Nature of the Pt-CeO2 Interface in Dry Reforming of Methane.

Single-atom catalysts (SACs) are attractive in one-carbon (C1) chemistry because of their high atom efficiency. However, it is a great challenge for understanding the dynamic roles of SACs under operating conditions. Here, isolated Pt atoms trapped on defective CeO2 surface are investigated by experiments, especially operando techniques, which offers basic understanding of the nature and dynamic evolution of the Pt-CeO2 interface in dry reforming of methane (DRM). The Pt-Olattice configuration is highly active for CH4 dissociation at the expense of the Olattice atoms, which in turn promotes the H-assisted dissociation of CO2. The transformation of Pt atoms between positive and metallic states is driven by the DRM reaction, which is essential for rendering highly efficient catalysis. The dynamic evolution of Pt atoms favors to eliminate the reactive intermediates, such as carbonates and formates. The dynamic nature of the Pt-CeO2 interface in the DRM reaction shows a similar picture to the Yin and Yang transformation in ancient Chinese Tai Ji wisdom.