Performance For CO2 Hydrogenation Research Articles

Superparamagnetic Iron Oxide Nanoparticles on ZrO2 as Catalysts for CO2 Hydrogenation to Lower Olefins

Organic synthesis presents significant opportunities for converting the abundant and hazardous carbon dioxide (CO2) in the atmosphere into a more sustainable carbon source. To reduce the carbon footprint, we explored the direct hydrogenation of CO2 to lower (C2‐4=) olefins using various catalysts composed of ZrO2‐supported alkali‐metal‐promoted superparamagnetic iron oxide nanoparticles (SPIONs; Fe3O4). These catalysts are notable for their straightforward preparation; we employed a cost‐effective dry‐mixing method to create a range of alkali metal‐doped SPIONs supported on ZrO2. Results showed that the strong interactions between Fe3O4 and the ZrO2 support enhanced CO2 hydrogenation performance compared to other forms, such as pristine Fe or Fe2O3. Under optimal conditions—using a gas hourly space velocity (GHSV) of 4500 mL/h/gcat and a feed ratio of H2:CO2 = 3:1—this catalyst achieved over 22% CO2 conversion and high selectivity for light (C2‐4=) olefins at 30 bar and 375 ºC, with 30 wt% Fe3O4 loading on ZrO2 and 2 wt% K promoter. We also investigated several variables, including alkali metal concentration, iron content, reaction conditions, and catalyst stability over 96 hours.

Controlling Metal-Support Interactions to Engineer Highly Active and Stable Catalysts for COx Hydrogenation.

This perspective focuses on the modulation of metal-support interaction (MSI) in catalysts for COx hydrogenation, highlighting their profound impact on catalytic performance. Firstly, it outlines different strategies, including the use of highly reducible oxides and moderate reduction treatments, which induce the classical strong metal-support interaction (SMSI) effect and the electronic metal-support interaction (EMSI) effect. Morphology engineering and crystalline phase manipulation of oxides presented as effective methods to control EMSI are also discussed. The discrimination of SMSI and EMSI can be achieved using oxides with low encapsulation tendencies, such as ZrO2, which supports electronic modifications without or minimizing the overgrowth issues, optimizing the catalytic performance for methanation. Then, the synergy between Cu and ZnO in methanol synthesis, enhanced by SMSI, is emphasized inside. Optimizing support oxides to control oxygen vacancies enhances the catalytic performance of CO2 hydrogenation to methanol. Perspectives for the future research on the fundamental understanding of structure-MSI-performance relationship for catalyst design is discussed.

Effective Screening of Metal Dopants for In2O3 Catalyst to Tune Catalytic Performance of CO2 Hydrogenation to Formic Acid

The metal doping is an effective strategy to adjust catalytic performance for indium oxide catalyst in CO2 hydrogenation. In current work, a series dopant, Co, Fe, Ni, Pd, Pt, Rh and Ru, are selected and examined in CO2 hydrogenation to formic acid by DFT based microkinetic simulation. It is found that substitutional doping is local effect which mainly promotes the reactivity of adjacent oxygen atoms. The calculations of both CO2 adsorption and hydrogen molecule dissociation certify the positive effects induced by doping, and the adsorption energy of CO2 has a linear relation with the transferred charges for all investigated catalysts which helps to explain the C‐O bond activation mechanism. Two pathways, Formate and Carboxyl, are investigated under same footing. It is noted that doping significantly reduces the hydrogenation barriers on two pathways compared with undoped surfaces. Moreover, the calculated TOF of formic acid formation is greatly increased on doped surfaces and Pt, Pd, Ru are identified as the most active dopants. In the end, it is concluded that reaction obeys Carboxyl mechanism and a valid descriptor of trans‐HCOOH* and H* formation energy is proposed for the screening of effective dopants.

Enhanced CO2 Hydrogenation Performance of CoCrNiFeMn High Entropy Alloys

CO2 hydrogenation is a promising process for removing anthropogenic CO2 emissions and yielding C1 chemicals that can be utilized as fuels and valuable precursors for chemical synthesis. Commercial high-entropy alloys (HEAs) have widespread application in various fields owing to their exceptional thermal stability and tunable microstructure. However, their potential application as catalysts is often limited by the low exposure of active sites. In this study, the commercial CoCrNiFeMn powder was applied for atmospheric pressure CO2 hydrogenation and enhanced its catalytic performance by a combined treatment of ball milling and high-temperature H2 reduction. The high-energy ball milling results in a morphological transition in CoCrNiFeMn HEAs from spherical to irregular. This transformation leads to a significant decrease in particle size and more surface reactive sites. The high-temperature H2 reduction promoted the atomic rearrangement on the CoCrNiFeMn surface, thereby improving its alloy structural homogeneity. These modifications greatly improve the performance of CoCrNiFeMn for CO2 hydrogenation. This work introduces a facile modification approach to facilitate the catalytic efficiency of commercial HEAs in CO2 hydrogenation with high selectivity.

Carbon-Supported Fe-Based Catalyst for Thermal-Catalytic CO2 Hydrogenation into C2+ Alcohols: The Effect of Carbon Support Porosity on Catalytic Performance

Carbon materials supported Fe-based catalysts possess great potential for the thermal-catalytic hydrogenation of CO2 into valuable chemicals, such as alkenes and oxygenates, due to the excellent active sites’ accessibility, appropriate interaction between the active site and carbon support, as well as the excellent capacities in C-O bond activation and C-C bond coupling. Even though tremendous progress has been made to boost the CO2 hydrogenation performance of carbon-supported Fe-based catalysts, e.g., additives modification, the choice of different carbon materials (graphene or carbon nanotubes), electronic property tailoring, etc., the effect of carbon support porosity on the evolution of Fe-based active sites and the corresponding catalytic performance has been rarely investigated. Herein, a series of porous carbon samples with different porosities are obtained by the K2CO3 activation of petroleum pitch under different temperatures. Fe-based active sites and the alkali promoter Na are anchored on the porous carbon to study the effect of carbon support porosity on the physicochemical properties of Fe-based active sites and CO2 hydrogenation performance. Multiple characterizations clarify that the bigger meso/macro-pores in the carbon support are beneficial for the formation of the Fe5C2 crystal phase for C-C bond coupling, therefore boosting the synthesis of C2+ chemicals, especially C2+ alcohols (C2+OH), while the limited micro-pores are unfavorable for C2+ chemicals synthesis owing to the sluggish crystal phase evolution and reactants’ inaccessibility. We wish our work could enrich the horizon for the rational design of highly efficient carbon-supported Fe-based catalysts.

Data-Driven Approaches for Predicting Catalyst Performance in CO2 Hydrogenation

This paper explores the critical role of data collection and preparation in leveraging machine learning techniques for predicting catalyst performance in CO2 hydrogenation processes. As the global community seeks sustainable solutions to mitigate carbon emissions, understanding the efficiency of catalysts in converting CO2 into valuable chemicals becomes increasingly important. The study discusses various types of data utilized in this context, including both experimental and simulation data, while highlighting their significance in comprehensively understanding key factors such as reaction rates, selectivity, and catalyst stability. For instance, the ability of a catalyst to selectively produce desired products over others can significantly impact the overall economic viability of CO2 hydrogenation processes. Furthermore, stability data sheds light on the longevity and durability of catalysts, revealing insights into deactivation mechanisms that can occur due to factors like sintering, poisoning, or leaching of active sites. On the other hand, simulation data generated from advanced computational methods such as density functional theory (DFT) and molecular dynamics (MD) provides a deeper understanding of the electronic and structural properties of catalysts. These computational techniques allow researchers to predict reaction pathways, activation energies, and the behavior of intermediate species, thereby complementing experimental findings and guiding the design of more effective catalysts. The paper also emphasizes the importance of utilizing publicly available databases and collaborative research datasets, which serve to enhance data accessibility and foster scientific collaboration among researchers in the field. By pooling resources and sharing findings, the scientific community can accelerate the discovery and optimization of novel catalysts. Additionally, the study outlines essential steps in the data preparation process, including rigorous data cleaning, preprocessing, and feature selection, all of which are crucial for ensuring the quality and reliability of the data used in machine learning models. The paper discusses the implementation of cross-validation techniques and performance metrics that help evaluate and validate model predictions, ensuring that the developed models generalize well to unseen data.

CO2 hydrogenation to light olefins over highly active and selective Ga-Zr/SAPO-34 bifunctional catalyst

The production of light olefins from the hydrogenation of CO2 is an efficient way to utilize CO2, where the surface oxygen vacancy in metal oxide plays an important role in CO2 adsorption and activation. Here, the Ga-Zr metal oxides were prepared by hydrolysis of urea at different temperatures and combined with SAPO-34 to prepare the bifunctional catalyst for CO2 hydrogenation to light olefins. The surface oxygen vacancy content of Ga-Zr oxide increases with increasing urea hydrolysis temperature, and a high CO2 conversion of 26.4% and C2=–C4= hydrocarbon selectivity of 87.2% were obtained by a well-matched amount of desorbed CO2 and H2. Using the CO2 and H2/HCOOH/CH3OH as probe molecules, the in-situ DRIFT spectra reveal that the CO2 could be activated on surface oxygen vacancy and converted to CO3* and HCO3* species, which were further hydrogenated to HCOO* and CH3O* species. While the by-product CO mainly originates from the decomposition of HCOO* and the presence of SAPO-34 converts CH3O* to C2=–C4=. The current study illustrates that boosting the surface oxygen vacancy in defected surfaces of metal oxide and providing a matching H2 dissociation ability is the key to improve the performance of CO2 hydrogenation to light olefins.

Morphology effects of CeO2 on the performance of CaO-Cu/ CeO2 for integrated CO2 capture and conversion to CO

CeO2 support inhibits CaO sintering, and oxygen vacancy influences CO2 hydrogenation performance, making CeO2 widely applied in Integrated CO2 capture and in-situ conversion technology for reverse water–gas shift (ICCC-RWGS). Oxygen vacancy concentration was dependent on the morphology of CeO2, which would affect metal dispersion and CO2 hydrogenation conversion. However, Very little is known about the morphology effect of CeO2 on the carbon capture and in-situ hydrogenation performance of DFMs. Here, Cu/CeO2 with different CeO2 morphologies was synthesized, and high Cu dispersion was achieved on Cu/CeO2-R, exhibiting the best CO2 hydrogenation performance. Integrated Cu/CeO2 with CaO by physical mixing method, CaO-Cu/CeO2 was used to investigate the morphology effects of CeO2 on the performance of CaO-Cu/CeO2 for integrated CO2 capture and conversion to CO. CaO-Cu/CeO2-R exhibited the best capture-hydrogenation performance (CO2 conversion rate of 75 %, CO production rate of 9.72 mmol/g). The CeO2-R provided more surface oxygen vacancies, enhancing carbonate hydrogenation. The larger specific surface area and {110} crystal plane of CeO2-rod enhanced Cu dispersion, and the smaller particle size of CeO2-R enhanced its interaction with CaO, improving the cyclic stability of CaO-Cu/CeO2-R. The hydrogenation performance of CaO-Cu/CeO2 was dependent on the morphology of CeO2, providing insights into the design of high-activity metal catalytic components in ICCC-RWGS.

Recent Advances in Alloy Catalysts for CO2 Hydrogenation to Methanol

AbstractThe increasing anthropogenic carbon dioxide emissions (CO2) have a huge environmental impact, and CO2 emission reduction is already a common view in our society. Recently, selective hydrogenation of CO2 to methanol has attracted much attention because the process can effectively mitigate CO2 emissions and simultaneously produce high‐value‐added chemicals and fuels. The catalysts play a very important role in achieving high efficiency of CO2 to methanol. As one promising alternative, the alloy catalysts have demonstrated high performance in CO2 hydrogenation to methanol due to their unique geometry and electronic properties. Herein, we review the recent advances in alloy catalysts, including solid solution alloys and intermetallic compounds (mainly Cu‐based, In‐based, Ga‐based, and other alloy catalysts) for heterogeneous catalysis of CO2 hydrogenation to methanol. Moreover, the research ideas and development prospects of alloy catalysts for CO2 hydrogenation to methanol are overviewed to provide the ideas and references for the subsequent research on alloy catalysts for CO2 hydrogenation.

Study on Catalytic Performance in CO2 Hydrogenation to Methanol over Au–Cu/C3N4 Catalysts

In this paper, Au and Cu nanoparticles were successfully loaded onto porous g-C3N4 material through a hydrothermal synthesis method. By adjusting the proportion of Cu, Au-5%Cu/C3N4, Au-10%Cu/C3N4, and Au-15%Cu/C3N4, catalysts were prepared and used for the catalytic reduction of CO2 to methanol. Characterization analysis using high-resolution XPS spectra showed that with an increase in the doping amount of Cu, the electron cloud density on the Cu surface initially increased and then decreased. Electrons from Au atoms transferred to Cu atoms, leading to the accumulation of a more negative charge on the Cu surface, promoting the adsorption of partially positively charged C in CO2, which is more beneficial for catalyzing CO2. Among them, Au-10%Cu/C3N4 exhibited good reducibility and strong basic sites, as demonstrated by H2-TPR and CO2-TPD, with the conversion rates for CO2, methanol yield, and methanol selectivity being 11.58%, 41.29 g·kg−1·h−1 (0.39 μmol·g−1s−1), and 59.77%, respectively.

Tuning the CO2 hydrogenation activity and selectivity of TiO2 nanorods supported Rh catalyst via secondary‐metals addition

AbstractSecondary‐metals promotion is key to tune the CO2 hydrogenation performance of Rh‐based catalyst. We describe the addition of Cu or Co in TiO2 nanorods supported Rh catalyst (viz., RhMx/TiO2), showing significant impact on the CO2 hydrogenation activity and productivity. Cu addition can promote the partial hydrogenation to alcohols (methanol and ethanol), whereas Co led to the deep hydrogenation to alkanes (CH4, C2H6). Comparative time‐resolved in situ DRIFTS studies with H2/D2 isotopic exchange further reveal that both surface adsorbed CO* and formates could be the key reaction intermediates during the CO2 hydrogenation over RhMx/TiO2 (especially the RhCu2.5/TiO2), in which the interaction strength of CO* regulated by secondary‐metals addition was key to tune the reaction pathways and productivity. The findings suggested that rational design of active metal sites, for example the synergy between Rh and secondary‐metals, is highly needed to promote the CO insertion and CC coupling to produce ethanol.

Synergistic effect of Fe-Mn bimetallic sites with close proximity for enhanced CO2 hydrogenation performance

Synergistic effect of Fe-Mn bimetallic sites with close proximity for enhanced CO2 hydrogenation performance

Theoretical study of the effects of surface Cu coordination environment on CO2 hydrogenation to CH3OH

The coordination environment of Cu (the coordination number and arrangement of surface atoms) plays an important role in CO2 hydrogenation to CH3OH. Compared with the extensive studies of the effects of coordination number, the comprehensive effects of coordination number and arrangement of surface atoms were seldom explored in literature. To unravel the effects of surface Cu coordination environment on CO2 hydrogenation to CH3OH, the adsorption and reaction behaviors of H2 and CO2 on Cu(111), (100), (110) and (211) with different coordination numbers and arrangement of surface Cu were systematically calculated by density functional theory (DFT) and kinetic Monte Carlo (kMC) simulation. It was found that the adsorption energies of intermediates in CO2 hydrogenation on Cu surfaces increase with the decrease of coordination number. When the Cu coordination numbers are similar, the charge density on the open surface derived from the different atom arrangement becomes larger and leads to stronger interaction with intermediates than that on the compact one. DFT calculation and kMC simulation indicate that methanol formation pathway follows CO2*→HCOO*→HCOOH*→H2COOH*→H2CO*→CH3O*→CH3OH* on four Cu facets; CO formation is via CO2 direct dissociation on Cu(111), (100) and (110) but COOH* dissociation on (211). The low-coordinated surface Cu with more openness on Cu(211) is the highly active site for CO2 hydrogenation to CH3OH with high turnover of frequency (3.71 × 10−4 s−1) and high selectivity (87.17 %) at 600 K, PCO2 = 7.5 atm and PH2 = 22.5 atm, which is much higher than those on Cu(111), (100) and (110). This work unravels the effects of coordination environment on CO2 hydrogenation at the molecular level and provides an important insight into the design and development of catalysts with high performance in CO2 hydrogenation to CH3OH.

Sodium-assisted MoS2 for boosting CO2 hydrogenation to methanol: The crucial role of sodium in defect evolution and modification

The effective conversion of CO2 to methanol utilizing green hydrogen under moderate conditions represents a promising approach for achieving carbon neutrality. MoS2 demonstrates exceptional catalytic performance at temperatures below 200 °C, however, generating in-plane sulfur defects is challenging due to the intact planar structure. Introducing heteroatoms to induce sulfur vacancy formation and modulate their chemical environment remains a significant obstacle. In this study, we developed a NaCl-assisted method for synthesizing MoS2 and discovered that a small quantity of sodium not only promotes the formation of sulfur vacancies during the induction period, but also encourages CO2 hydrogenation via the carboxylate route, as opposed to the CO2 dissociation to CO* route over non-modified sulfur vacancies. Furthermore, catalysts at various stages throughout the 60 h induction period were characterized, revealing that the increase in sulfur vacancies and enhanced H2 dissociation capability are primary factors contributing to improved methanol yield. The sodium-modified MoS2 achieves a methanol space–time yield of up to 571 mgMeOH gcat.−1 h−1 at 200 °C and 5 MPa with a 4.8% CO2 conversion and 96% methanol selectivity. The turnover frequency based on total sulfur vacancies reaches 170 h−1. This research is anticipated to offer a new strategy for enhancing the catalytic performance of CO2 hydrogenation to methanol using heteroatom-assisted defect engineering.

Exploring the Effect of the Solvothermal Time on the Structural Properties and Catalytic Activity of Cu-ZnO-ZrO2 Catalysts Synthesized by the Solvothermal Method for CO2 Hydrogenation to Methanol

A series of Cu-ZnO-ZrO2 (CCZ) catalysts were prepared by the solvothermal method with different solvothermal times (1 h, 3 h, 6 h, and 12 h). The physicochemical properties of these catalysts and the catalytic performance for CO2 hydrogenation to methanol were studied. The highest methanol yield was achieved when the solvothermal time was 6 h (CCZ-6). Furthermore, we found that the copper surface area (SCu) increases and then decreases with an increase in the solvothermal time and that there is a strong correlation between the methanol yield and the SCu. This research highlights the crucial influence of the solvothermal time on the structure and catalytic behavior of Cu-ZnO-ZrO2 catalysts, providing a valuable reference for the development of efficient catalysts.

Sustainable approach for CO2 hydrogenation to formic acid with Ru single atom catalysts on nitrogen-doped carbon prepared from green algae

Ruthenium catalysts supported on nitrogen-doped carbon (NDC) have gained attention due to their exceptional catalytic performance for CO2 hydrogenation to formic acid, a key solution to mitigate CO2 emissions. However, conventional methods for preparing NDC typically rely on petrochemical compounds, which are not environmentally friendly. Herein, we propose a sustainable and innovative approach by employing protein-rich green algae as a source to prepare NDC for Ru catalysts. To maximize the CO2 reduction effect, flue gas exhausted from industrial processes was utilized as a CO2 feed to cultivate the green algae in a photobioreactor. The harvested green algae were pyrolyzed at 800 °C under an N2 atmosphere to prepare the NDC. After the metalation of Ru on prepared NDC, the Ru catalysts exhibited a turnover number of 7,599 for CO2 hydrogenation which demonstrated the potential of green algae as a raw material for NDC. However, the catalysts were deactivated due to the leaching or agglomeration of weakly bound Ru analyzed by experimental and theoretical investigations. We applied a NaBH4 treatment to stabilize the Ru active sites, and the treated catalysts retained 99.6 % of their initial catalytic activity after five recycling tests. Furthermore, Ru on NDC achieved a cumulative turnover number of 16,000 after 24 h. This study offers a sustainable and eco-friendly method for reducing CO2 emissions, combining the cultivation of green algae with waste flue gas and the production of formic acid via CO2 hydrogenation using improved Ru catalysts on algae-derived NDC.

On the Capabilities of Transition Metal Carbides for Carbon Capture and Utilization Technologies.

The search for cheap and active materials for the capture and activation of CO2 has led to many efforts aimed at developing new catalysts. In this context, earth-abundant transition metal carbides (TMCs) have emerged as promising candidates, garnering increased attention in recent decades due to their exceptional refractory properties and resistance to sintering, coking, and sulfur poisoning. In this work, we assess the use of Group 5 TMCs (VC, NbC, and TaC) as potential materials for carbon capture and sequestration/utilization technologies by combining experimental characterization techniques, first-principles-based multiscale modeling, vibrational analysis, and catalytic experiments. Our findings reveal that the stoichiometric phase of VC exhibits weak interactions with CO2, displaying an inability to adsorb or dissociate it. However, VC often exhibits the presence of surface carbon vacancies, leading to significant activation of CO2 at room temperature and facilitating its catalytic hydrogenation. In contrast, stoichiometric NbC and TaC phases exhibit stronger interactions with CO2, capable of adsorbing and even breaking of CO2 at low temperatures, particularly notable in the case of TaC. Nevertheless, NbC and TaC demonstrate poor catalytic performance for CO2 hydrogenation. This work suggests Group 5 TMCs as potential materials for CO2 abatement, emphasizes the importance of surface vacancies in enhancing catalytic activity and adsorption capability, and provides a reference for using the infrared spectra as a unique identifier to detect oxy-carbide phases or surface C vacancies within Group 5 TMCs.

Flame Spray Pyrolysis Synthesis of Ultra-Small High-Entropy Alloy-Supported Oxide Nanoparticles for CO2 Hydrogenation Catalysts.

The synthesis of high-entropy alloys (HEAs) with ultra-small particle sizes has long been a challenging task. The complex and time-consuming synthesis process hinders their practical application and widespread adoption. This study presents the novel synthesis of TiO2 nanoparticles loaded with a quinary high-entropy alloy through flame spray pyrolysis (FSP) for the first time. The extremely fast heating rate of flame combustion makes the precursor fast pyrolysis gasification, high temperature in the flame field promotes the metal vapor mixing uniformly, and the fast quenching process can reduce the particle aggregation sintering, the ultra-small particle size of HEA firmly attached to the TiO2 surface. The catalysts prepared via this gas-to-particle pathway exhibit excellent performance in CO2 hydrogenation, achieving a conversion rate of 62% at 450°C, and maintaining their activity for over 220h without significant particle agglomeration. This finding provides valuable insights for the future design of catalytically active materials with enhanced activity and long-term stability.

Rich oxygen vacancies in core–shell structured Co3O4-CuO-ZnO@ZIF-8 for boosting CO2 hydrogenation to methanol

Converting carbon dioxide (CO2) into high-quality methanol to alleviate the energy crisis is a promising strategy. However, as a traditional catalyst for CO2 hydrogenation to methanol, Cu/ZnO exhibits low CO2 conversion and low methanol selectivity at low temperature. In order to improve the catalytic performance of CO2 hydrogenation to methanol, Co3O4 was introduced to form Co3O4-CuO-ZnO with flower-like structure, and then diamond-shaped ZIF-8 particles with large specific surface area and rich oxygen vacancies were synthesized on the surface of Co3O4-CuO-ZnO by hydrothermal method. A series of characterizations showed that the synthesis of ZIF-8 greatly increased the specific surface area of the catalyst. The oxygen vacancy is the site of CO2 adsorption and activation, and stabilizes the reaction intermediate, which promotes the conversion of CO2 and the formation of methanol. The introduction of Co promotes the formation of the alloy phase, enhances the interaction between the metals, makes the active center more dispersed, reduces the sintering of the catalyst, and thus exhibits better catalytic performance. Among co-precipitated CuO-ZnO, hydrothermal CuO-ZnO, CuO-ZnO@ZIF-8, Co3O4-CuO-ZnO and Co3O4-CuO-ZnO@ZIF-8 catalysts, Co3O4-CuO-ZnO@ZIF-8 exhibits the best catalytic performance (CO2 conversion 16.06% and CH3OH selectivity 94.58%). Based on the above design, ZIF-8 and Co3O4 synergistic CuO-ZnO catalyst effectively improved CO2 conversion and CH3OH selectivity.

Preparation of palladium-based catalyst by plasma-assisted atomic layer deposition and its applications in CO2 hydrogenation reduction

Supported Pd catalyst is an important noble metal material in recent years due to its high catalytic performance in CO2 hydrogenation. A fluidized-bed plasma assisted atomic layer deposition (FP-ALD) process is reported to fabricate Pd nanoparticle catalyst over γ-Al2O3 or Fe2O3/γ-Al2O3 support, using palladium hexafluoroacetylacetonate as the Pd precursor and H2 plasma as counter-reactant. Scanning transmission electron microscopy exhibits that high-density Pd nanoparticles are uniformly dispersed over Fe2O3/γ-Al2O3 support with an average diameter of 4.4 nm. The deposited Pd-Fe2O3/γ-Al2O3 shows excellent catalytic performance for CO2 hydrogenation in a dielectric barrier discharge reactor. Under a typical condition of H2 to CO2 ratio of 4 in the feed gas, the discharge power of 19.6 W, and gas hourly space velocity of 10000 h−1, the conversion of CO2 is as high as 16.3% with CH3OH and CH4 selectivities of 26.5% and 3.9%, respectively.