Catalytic Activity For CO2 Methanation Research Articles

Plasma‐catalytic CO2 methanation over NiO/bentonite catalysts prepared by solution combustion synthesis

AbstractA solution combustion synthesis (SCS) process to prepare nickel catalyst over bentonite (NiO/Ben) is reported. Compared to the traditional impregnation method, NiO/ben produced by SCS has smaller nickel particle size and higher dispersion. With a metal loading of 20 wt%, the afforded NiO/Ben demonstrates excellent catalytic activity for CO2 methanation in a dielectric barrier discharge reactor. In certain discharge conditions (H2:CO2 ratio of 5 in feed gas, discharge input power of 45 W, and gas hourly space velocity of 11 320 h−1), CO2 conversion and CH4 selectivity are as high as 55.8% and 84.6%, respectively. Under the conditions of plasma configuration, the strong interaction between the nickel species and the support plays an important role in the CO2 methanation process.

A superior strategy for CO2 methanation under atmospheric pressure: Organic acid-assisted Co nanoparticles assembly on diatomite

There is an urgent need to find a cost-effective and energy-efficient catalysts to promote industrial CO2 methanation, and organic acid-assisted Co/diatomite catalysts stands out as a promising alternative strategy. Herein, nine different kinds of organic acid were introduced to assist the assembly of Co nanoparticles on surface of the diatomite (Dt). Among these catalysts, the superior catalytic performance on citric acid (CA)–Co/Dt was attributed to the fact that CA has more hydroxyl and carboxyl groups. The amount of citric acid addition was adjusted to reach the optimal CA/Co molar ratio and consequently the best catalytic performance. 0.5CA-Co/Dt catalyst showed excellent catalytic activity for CO2 methanation with 73% CO2 conversion and 96% CH4 selectivity at 400 °C (GHSV = 20000 mL gcat−1 h−1, P = 1 atm), and exhibited good stability in long-term reaction. The addition of citric acid changed the surface properties, such as the morphology of Co3O4, cobalt oxidation state, basic sites and defect sites, which affected the catalytic performance. The mechanism analysis showed that the improved catalytic performance was attributed to the refinement and increased dispersion of Co nanoparticles, which increased the active catalytic sites on the catalyst surface, enhanced metal-support interaction, and improved the anti-sintering properties. The outstanding features of CA-assisted Co/Dt provide another promising strategy for the design of high-performance CO2 methanation catalysts.

Catalytic Performance for CO Methanation over Ni/MCM-41 Catalyst in a Slurry-Bed Reactor

The Ni-based catalyst has been intensively studied for CO methanation. Here, MCM-41 is selected as support to prepare xNi/MCM-41 catalysts with various Ni contents and the catalytic performance for CO methanation in a slurry-bed reactor is investigated under different reaction conditions. The CO conversion gradually increases as the reaction temperature or pressure rises. As the Ni content increases, the specific surface area and pore volume of xNi/MCM-41 catalysts decrease, the crystallite sizes of metallic Ni increase, while the metal surface area and active Ni atom numbers firstly increase and then slightly decrease. The 20Ni/MCM-41 catalyst with the Ni content of 20 wt% exhibits the highest catalytic activity for CO methanation, and the initial CH4 yield rate is well correlated to the active metallic Ni atom numbers. The characterization of the spent xNi/MCM-41 catalysts shows that the agglomeration of Ni metal is accountable for the catalyst deactivation.

Effect of reduction degree of Ni-phyllosilicate on the catalytic performance for CO2 methanation: Regulation of catalyst structure and hydroxyl group concentration

In order to reveal the interrelationship among reduction degree and catalyst structure as well as surface hydroxyl group concentration of Ni-phyllosilicate, four different reduction temperatures of 550, 600, 700 and 800 °C were used. The results showed that low-temperature reduction could lead to high catalytic activity for CO2 methanation. In detail, the low-temperature partial reduction catalyst treated at 550 °C (Ni/S-550R) obtained the smallest Ni particle size, the highest specific surface area and the largest pore volume, which were beneficial to the chemisorption and activation of H2. In addition, the unreduced nickel phyllosilicate also provided abundant hydroxyl groups to facilitate the activation of CO2. With the increasing of reduction temperature, the reduction degree increased quickly; however, the TEM and XRD results showed that the Ni sintering was serious reduced at 700 or 800 °C. What's more, the SiO2 support also transferred from amorphous to crystalline at high reduction temperature with the significant collapse of pore structure. In all, a series of characterization results displayed that the low-temperature reduction of Ni-phyllosilicate catalyst exhibited strong H2 and CO2 chemisorption and activation capacity compared with the high-temperature-reduction ones leading to high CO2 methanation activity.

Synergistic effect of double solvent and accelerator on efficient synthesis of nickel phyllosilicate for CO2 methanation

In order to facilitate the synthesis of nickel phyllosilicate through the hydrothermal method, different process parameters including high or low hydrothermal temperature, single or double solvent, and with or without accelerator were investigated in this work. The Ni/DA-150-6 catalyst prepared in the presence of double solvent and the accelerator exhibited high Ni content, small Ni crystal size, and large H2 and CO2 chemisorption capacity, leading to the highest catalytic activity for CO2 methanation. Meanwhile, Ni/S-200-12 synthesized by the high-temperature (200 °C) hydrothermal method or Ni/D-150-12 prepared at 150 °C in the presence of double solvent displayed low catalytic activity owing to the low Ni content. In short, the synergistic effect of double solvent and accelerator is the most significant strategy for the efficient synthesis of Ni-phyllosilicate.

Carbon dioxide methanation over Ni catalysts prepared by reduction of NixMg3‒xAl hydrotalcite-like compounds: Influence of Ni:Mg molar ratio

A series of supported Ni catalysts have been prepared from NixMg3‒xAl hydrotalcite-like compounds (HTlcs) and the influence of Ni:Mg molar ratio on the structural property and catalytic activity for CO2 methanation is investigated. The catalysts were characterized by N2 physical adsorption, X-ray powder diffraction (XRD), temperature-programmed reduction (H2-TPR), temperature-programmed desorption (CO2-TPD), H2 chemisorption, scanning electronic microscopy (SEM), scanning transmission electronic microscopy (STEM), and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). By reducing HTlcs at 800 °C, well dispersed Ni particles with average size of 5–10 nm are formed. The Ni crystal size decreases with the decrease of Ni:Mg ratio, attributable to the strong interaction between nickel and magnesium oxides. Among the catalysts, Ni2Mg1Al-HT shows the highest activity, giving ∼93% CO2 conversion and >99% CH4 selectivity at 275 °C and SV = 5000 mL g−1 h−1. Meanwhile, this catalyst exhibits good stability without obvious sintering and coking. The high activity is related to the large amount of surface Ni0 species and medium basic sites. From CO2-TPD and DRIFTS, it is inferred that CO2 adsorbs on the medium basic sites, i.e., Ni–Mg(Al)O interface, forming monodentate carbonate. In situ DRIFTS reveals that monodentate carbonate, monodentate formate, and adsorbed CO are the main intermediate species, suggesting that the reaction may proceed via the formate formation route.

Efficient utilization of silanol group in rice husk to promote the synthesis of Ni-phyllosilicate for CO2 methanation

It is a challenge to prepare Ni-phyllosilicate catalysts deriving from the reaction of nickel salts and biomass-based silica with high Ni contents. In order to efficiently synthesize nickel phyllosilicate, the acid-treated rice husk without calcination (P-R) was directly used as the raw material. The as-synthesized Ni-phyllosilicate (N/P-R) exhibited high nickel content of 46.7 wt% owing to utilization of the abundant silanol group in the fresh rice husk. On the contrary, the Ni content of Ni-phyllosilicate sample (N/R–S) prepared using the calcinated rice husk-based silica was only 4.8 wt% because of the loss of silanol group during calcination process. As a result, N/P-R displayed much higher catalytic activity for CO2 methanation than N/R–S. It was found that the silanol group was in favour of forming the important intermediate Si(OH)4, and thereby facilitated the formation of nickel phyllosilicate. In addition, the N/P-R catalyst demonstrated superior stability and excellent anti-sintering ability in the long lifetime test. In short, the proposed method in this work could not only efficiently synthesize nickel phyllosilicate with high Ni content, but also reduce energy consumption and operation steps compared to the one prepared using biomass-based silica.

Slag-based geopolymer microspheres as a support for CO2 methanation

Reducing the emission of CO2 and converting it into energy are the key issues researchers are concerned about. Geopolymers with the advantage of alkali metal synergistic catalysis and excellent ability to adsorb metals are promising catalyst supports. To prove this point, KOH-activated chemically synthesized slag (CaO-MgO-Al2O3-SiO2) and ground granulated blast furnace slag were used as the raw materials in this study to prepare CO2 methanation catalysts. Ni metal (15 wt%) was loaded onto the slag-based geopolymers using the incipient wetness impregnation method. The as-synthesized slag-based geopolymer and real slag-based geopolymer catalysts were prepared and denoted as Ni-P-SGS and Ni-S-SGS, respectively. The results showed that the Ni-P-SGS catalyst showed better Ni dispersion, more alkaline sites, and stronger CO2 adsorption capacity, and hence higher catalytic activity for CO2 methanation than the Ni-S-SGS catalyst. Therefore, the Ni-P-SGS catalyst showed a CO2 conversion of 80.2% and a CH4 selectivity of 99.2% at 400 °C/0.1 MPa and a weight hourly space velocity of 12000 mL g-−1h−1. This performance is superior to that of the Ni-S-SGS catalyst, which showed a CO2 conversion of 72.8% and CH4 selectivity of 98.3%. In addition, the hydrogenation of formate seemed to be the rate-limiting step for the formation of CH4. This work provides sufficient evidence that geopolymers are promising catalyst supports.

Photo-enhanced thermal catalytic CO2 methanation activity and stability over oxygen-deficient Ru/TiO2 with exposed TiO2 {001} facets: Adjusting photogenerated electron behaviors by metal-support interactions

In this study, two Ru/TiO2 samples with different TiO2 facets were prepared to investigate their photo-thermal catalytic CO2 + H2 reaction behavior. Without UV irradiation, the Ru/TiO2 with 67% {001} facet (3RT) displayed improved thermal catalytic activity for CO2 methanation than that of Ru/TiO2 with 30% {001} facet (0RT). After H2 pretreatment, both samples exhibited enhanced thermal catalytic activities, but the H2-treated 3RT (3RT-H) exhibited superior activity to that of the H2-treated 0RT (0RT-H). Under UV irradiation, 3RT-H exhibited apparent photo-promoted thermal catalytic activity and stability, but the enhanced catalytic activity was lower than that of 0RT-H. Based on the characterization results, it is proposed that both the surface oxygen vacancies (Vos) (activating CO2) and the metallic Ru nanoparticles (activating H2) were mainly responsible for CO2 methanation. For 0RT, H2 pretreatment and subsequent UV irradiation did not promote the formation of Vos, resulting in low catalytic activity. For 3RT, on the one hand, H2 pretreatment promoted the formation of Vos, which were regenerated under UV irradiation; on the other hand, the photogenerated electrons from TiO2 transferred to Ru to maintain the metallic Ru nanoparticles. Both behaviors promoted the activation of CO2 and H2 and enhanced CO2 methanation. Moreover, the photogenerated holes favored the dissociated H at Ru migrating to TiO2, also promoting CO2 methanation. These behaviors occurring on 3RT-H may be attributed to the suitable metal-support interaction between the Ru nanoparticles and TiO2 {001}, resulting in the easy activation of lattice oxygen in TiO2 to Vos. With reference to the analysis of intermediates, a photo-thermal reaction mechanism is proposed for the Ru/TiO2 {001} facet sample.

Which is the better catalyst for CO2 methanation – Nanotubular or supported Ni-phyllosilicate?

In order to investigate effects of morphology and crystalline phase of different Ni-phyllosilicate catalysts on the catalytic performance for CO2 methanation, nanotubular Ni-phyllosilicate and MCM-41 supported Ni-phyllosilicate were synthesized through hydrothermal reaction of sodium silicate or MCM-41 with nickel nitrate. On one hand, nanosheets attributing to 2:1 type nickel phyllosilicate (Ni3Si4O10(OH)2·5H2O) were uniformly grown on the surface of MCM-41 spheres to form the MCM-41 supported Ni-phyllosilicate (Ni/M). On the other hand, 1:1 type Ni-phyllosilicate with nanotubular morphology (Ni/N) was synthesized through the reaction of Na2SiO3 and nickel nitrate. After a series of tests and characterizations, it was found that Ni/N exhibited low thermal stability and poor anti-sintering property, leading to poor catalytic activity for CO2 methanation. On the contrary, Ni/M was very stable, which obtained unchanged morphology and fine Ni particles after 750oC-reduction, resulting in high catalytic activity and long-term stability for CO2 methanation. In all, morphology and crystalline phase of Ni-phyllosilicate obviously affected catalytic performance, and the supported Ni-phyllosilicate catalyst was much better than the nanotubular Ni-phyllosilicate for CO2 methanation in this work.

Nickel phyllosilicate derived Ni/SiO2 catalysts for CO2 methanation: Identifying effect of silanol group concentration

For the conventional Ni/SiO2 catalyst, the weak metal-support interaction usually resulted in serious Ni sintering at high temperature. To address this problem, a group of Ni-phyllosilicate-derived Ni/SiO2 catalysts were synthesized via the hydrothermal reaction of nickel nitrate and mesostructured silica nanoparticles (MSN) with three different sizes of 99 (MS), 184 (MM), and 725 (ML) nm. The Ni contents of three nickel phyllosilicate catalysts varied from 5.9 to 19.7 wt%, which exhibited a reverse order of the particle size. It was found that the concentration of silanol group (SiOH) of MSN significantly affected the construction of Ni-phyllosilicate material. The surface silanol group concentration increased with the decrease of particle size of MSN, resulting in the improved formation of nickel phyllosilicate and enhanced catalytic activity for CO2 methanation. Among all catalysts, MS/H-24 showed the highest CO2 conversion of 76.5 % at 450 °C due to the highest Ni dispersion and largest CO2 and H2 uptakes. In addition, the optimal catalyst exhibited higher anti-sintering property, long-term stability and hydrothermal stability than an impregnated catalyst (Ms/Im) with the similar Ni content in a lifetime test (450 °C, 100 h) and steam treatment test (600 °C, 6 h), owing to its strong metal-support interaction derived from nickel phyllosilicate.

Highly Efficient Ni-Phyllosilicate Catalyst with Surface and Interface Confinement for CO2 and CO Methanation

For the conventional Ni/SiO2 catalyst, it is a challenge to address the sintering problem of Ni particles, especially at high Ni loading. A series of Ni-phyllosilicate catalysts were prepared through the hydrothermal reaction of mesoporous SiO2 nanorods (SRs) and nickel nitrate, followed by an impregnation modification of CeO2. Hydrothermal temperature played an important role in the formation of nickel phyllosilicate. A small amount of Ni-phyllosilicate with a Ni content of 18.56 or 23.88 wt % was formed at a low hydrothermal temperature of 120 or 160 °C, and a large amount of nanosheet-like Ni-phyllosilicate with the Ni content as high as 31.65 wt % was obtained at a high hydrothermal temperature of 200 °C. The prepared Ni-phyllosilicate catalysts were beneficial to obtain Ni particles with small sizes (3.3–6.3 nm), even though they were reduced at 750 °C and possessed high Ni loadings (18.56–31.65 wt %) owing to the surface and interface confinement of nickel phyllosilicate. After the modification of CeO2 using an impregnation method, the CeO2 promoter could further reduce the Ni particle size and increase hydrogen and carbon dioxide uptakes. The CeO2-modified Ni-phyllosilicate catalyst (NPS-180-5C) was the best catalyst in this work, which could reach the thermodynamic equilibrium of CO methanation above 350 °C and exhibited high catalytic activity for CO2 methanation. In addition, for the 55 °C-100 h-lifetime test for CO2 methanation and 600 °C-6 h-100% steam treatment tests, NPS-180-5C also showed an excellent antisintering property and higher hydrothermal stability than the impregnated one (N/SR-Im) owing to its special structure and confinement effect as well as promotion of CeO2 species. In all, the CeO2-modified SR-derived Ni-phyllosilicate catalyst could not only effectively suppress the problem of easy sintering of metallic Ni particles on the conventional Ni/SiO2 catalysts but also exhibit high catalytic activity and hydrothermal stability, which was a promising catalyst for both CO2 and CO methanation reactions.

Development of Catalytic Methanation as a Solution of CO2 Utilization

IHI is now dedicated to developing the carbon capture and utilization (CCU) technology. A methanation catalyst with great robustness and superior catalytic activity for CO2 methanation has been developed together with Institute of Chemical and Engineering Science (ICES), A*STAR. The catalyst has a unique microstructure in which nano-Ni particles are embedded in mesoporous SiO2 matrix. Over 3,000 hrs, the catalyst showed the stable performance without any sign of deactivation. An isothermal type reactor with methane production capacity of 1.25 Nm3-CH4/hr was designed and operated successfully. Numerical simulation was also performed to further scale up the reactor.

Effect of Fe and Co promoters on CO methanation activity of nickel catalyst prepared by impregnation – co-precipitation method

Abstract Ni based catalysts supported on γ-Al2O3 that was unpromoted (Ni/γAl2O3) or promoted (Ni–Fe/γAl2O3, Ni–Co/γAl2O3, and Ni–Fe–Co/γAl2O3) were prepared using by the impregnation – co-precipitation method. Their catalytic performances for CO methanation were studied at 3 atm with a weight hourly space velocity (WHSV) of 3000 ml/g/h of syngas with a molar ratio of H2/CO = 3 and in the temperature range between 130 and 350 °C. All promoters could improve nickel distribution, and decreased its particle sizes. It was found that the Ni–Co/γAl2O3 catalyst showed the highest catalytic performance for CO methanation in a low temperature range (<250 °C). The temperatures for the 20% CO conversion over Ni–Co/γAl2O3, Ni–Fe/γAl2O3, Ni–Fe–Co/γAl2O3 and Ni/γAl2O3 catalysts were 205, 253, 263 and 270 °C, respectively. The improved catalyst distribution by the addition of cobalt promoter caused the formation of β type nickel species which had an appropriate interacting strength with alumina support in the Ni–Co/γAl2O3. Though an addition of iron promoter improved catalyst distribution, the methane selectivity was lowered due to acceleration of both CO methanation and WGS reaction with the Ni–Fe/γAl2O3. Moreover, it was found that there was no synergetic effect from the binary Fe–Co promotors in the Ni–Fe–Co/γAl2O3 on catalytic activity for CO methanation.

Enhancing CO2 Hydrogenation to Methane by Ni-Based Catalyst with V Species Using 3D-mesoporous KIT-6 as Support

Using renewable H2 for CO2 hydrogenation to methane not only achieves CO2 utilization, but also mitigates the greenhouse effect. In this work, several Ni-based catalysts with V species using 3D-mesoporous KIT-6 (Korea Advanced Institute of Science and Technology, KIT) as support were prepared at different contents of NiO and V2O5. Small Ni nanoparticles with high dispersibility on 20Ni-0.5V/KIT-6 were identified by X-ray diffraction (XRD), TEM and hydrogen temperature-programmed desorption (H2-TPD) analysis, which promoted the production of more Ni active sites for enhancing catalytic activity for CO2 methanation. Moreover, TEM and hydrogen temperature-programmed reduction (H2-TPR) characterizations confirmed that a proper amount of Ni and V species was favorable to preserve the 3D-mesoporous structure and strengthen the interaction between active Ni and KIT-6. The synergistic effect between Ni and V could strengthen surface basicity to elevate the ability of CO2 activity on the 20Ni-0.5V/KIT-6. In addition, a strong interaction with the 3D-mesoporous structure allowed active Ni to be firmly anchored onto the catalyst surface, which was accountable for improving catalytic activity and stability. These results revealed that 20Ni-0.5V/KIT-6 was a catalyst with superior catalytic activity and stability, which was considered as a promising candidate for CO2 hydrogenation to methane.

Influence of Nickel Loading on Reduced Graphene Oxide-Based Nickel Catalysts for the Hydrogenation of Carbon Dioxide to Methane

In this study, a series of novel nickel catalysts supported on reduced graphene oxide nanosheets (Ni/rGO) with Ni loadings of 10, 15 and 20 wt% were successfully synthesized via the incipient wetness impregnation method. The physicochemical properties of the catalysts and rGO support were thoroughly characterized by thermogravimetric analyser, X-ray diffraction, fourier-transform infrared spectroscopy, Raman spectroscopy, N2 adsorption-desorption, temperature programmed reduction, temperature programmed CO2 desorption and field emission scanning electron microscopy with energy dispersive X-ray spectroscopy. The properties of the catalysts are correlated to its catalytic activity for CO2 methanation which were investigated using three-phase slurry reactor at low temperature and pressure of 240 °C and 10 bar, respectively. Among the three catalysts of different Ni loading, Ni15/rGO shows the highest activity of 51% conversion of CO2 with total selectivity towards CH4. N2-physisorption and CO2-TPD analysis suggest that high catalytic performance of Ni15/rGO is attributed to the high surface area, strong basic sites and special support effect of rGO in anchoring the active metal.

Low-temperature Conversion of Carbon Dioxide to Methane in an Electric Field

CO2 methanation was conducted at low temperatures with an electric field. Results show that 5 wt %Ru/CeO2 catalyst exhibited high and stable catalytic activity for CO2 methanation with the electric...

Low Temperature Methanation of CO2 on High Ni Content Ni-Ce-ZrOδ Catalysts Prepared via One-Pot Hydrothermal Synthesis

Ni-Ce-Zr-Oδ catalysts were prepared via one-pot hydrothermal synthesis. It was found that Ni can be partially incorporated into the Ce-Zr lattice, increasing surface oxygen species. The catalysts possess high surface areas even at high Ni loadings. The catalyst with Ni content of 71.5 wt.% is able to activate CO2 methanation even at a low temperature (200 °C). Its CO2 conversion and methane selectivity were reported at 80% and 100%, respectively. The catalyst was stable for 48 h during the course of CO2 methanation at 300 °C. Catalysts with the addition of medium basic sites were found to have better catalytic activity for CO2 methanation.

Prepared self-growing supported nickel catalyst by recovering Ni (Ⅱ) from metal wastewater using geopolymer microspheres

Here, new and effective microsphere adsorbents were synthesized by NaOH activating slag based geopolymer (Na-SGS). These microsphere adsorbents upset the adsorption equilibrium with the maximum Ni2+ adsorption capacity of 414.38 mg/g which is much larger than that of other geopolymer materials. After Ni2+ adsorption from simulated nickel electroplating wastewater, more active positions for the adsorption Ni2+ ions on Na-SGS were provided as shifts from the average pore diameter of 22.00–7.44 nm, the pore volume of 0.06 to 0.25 cm3/g, the Brunauer-Emmett-Teller (BET) surface area of 10.46–125.35 m2/g and the apparent change of new morphology. Moreover, the adsorbed Ni2+ species were distributed uniformly on Na-SGS. Thermodynamic performance reflected an exothermic, spontaneous and molecular disorder adsorption process, which can be easily controlled by the pH, dosage, initial concentration, contact time and temperature. Through the controllable adsorption, Na-SGS after Ni2+ adsorption (Na-SGS-Ni) was recycled and then reduced to be directly supported nickel catalysts (red-Na-SGS-Ni), which showed superior catalytic activity for CO2 methanation. Although the highest percent of CO2 conversation (XCO2 =99.54%) and methane selectivity (SCH4 =99.5%) are both at 300 °C, red-Na-SGS-Ni performed good XCO2 (99.48%) and SCH4 (98.2%) at low temperatures (100 °C).

A Facile Method for Preparing UiO-66 Encapsulated Ru Catalyst and its Application in Plasma-Assisted CO2 Methanation.

With increasing applications of metal-organic frameworks (MOFs) in the field of gas separation and catalysis, the preparation and performance research of encapsulating metal nanoparticles (NPs) into MOFs (M@MOF) have attracted extensive attention recently. Herein, an Ru@UiO-66 catalyst is prepared by a one-step method. Ru NPs are encapsulated in situ in the UiO-66 skeleton structure during the synthesis of UiO-66 metal-organic framework via a solvothermal method, and its catalytic activity for CO2 methanation with the synergy of cold plasma is studied. The crystallinity and structural integrity of UiO-66 is maintained after encapsulating Ru NPs according to the X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). As illustrated by X-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy (HRTEM), and mapping analysis, the Ru species of the hydration ruthenium trichloride precursor are reduced to metallic Ru NPs without additional reducing processes during the synthesis of Ru@UiO-66, and the Ru NPs are uniformly distributed inside the Ru@UiO-66. Thermogravimetric analysis (TGA) and N2 sorption analysis show that the specific surface area and thermal stability of Ru@UiO-66 decrease slightly compared with that of UiO-66 and was ascribed to the encapsulation of Ru NPs in the UiO-66 skeleton. The results of plasma-assisted catalytic CO2 methanation indicate that Ru@UiO-66 exhibits excellent catalytic activity. CO2 conversion and CH4 selectivity over Ru@UiO-66 reached 72.2% and 95.4% under 13.0 W of discharge power and a 30 mL·min−1 gas flow rate (), respectively. Both values are significantly higher than pure UiO-66 with plasma and Ru/Al2O3 with plasma. The enhanced performance of Ru@UiO-66 is attributed to its unique framework structure and excellent dispersion of Ru NPs.