High Catalyst Research Articles

In-situ generation of metal nanoparticle decorated N-doped carbon secondary reticular structure on coaxial electrospinning fibers for oxygen electrocatalysis

Combining metal-organic frameworks with electrospinning technology, this work employs coaxial electrospun fibers decorated with ZIF-67 as precursors. The Fe3+/Co2+/Ni2+ ions in the electrospun fibers are converted into FeCoNi alloy nanoparticles which catalyze the pyrolysis of ZIF-67 on the fiber surface to generate reticulated carbon microfibers. This produces an efficacious bifunctional oxygen electrocatalyst. This new N-doped carbon hierarchical network (NCHNs) catalyst with a distinct secondary reticulated carbon structure possesses larger surface area and pore volume. Besides, the decoration of FeCoNi nanoparticles on the NCHNs provides effective active sites. With rapid mass and electron transfer between the hollow fibers, the synergistic effect between the FeCoNi nanoparticles and the layered carbon network can contribute to the high activity and kinetics of oxygen electrochemistry. At 10 mA cm−2, the FeCoNi/NCHNs exhibit an ORR half-wave potential of 0.885 V and an OER potential of 1.610 V, which exceeds that of the existing Pt/C and RuO2 catalysts. Furthermore, the FeCoNi/NCHNs-based rechargeable Zn-Air battery has an excellent power density (160.5 mV cm−2), high open-circuit voltage (1.48 V), large specific capacity (792 mAh g−1) and excellent cycling stability (>200 h). This work provides a convenient method for designing high performance and low cost catalysts.

High efficient manganese‑nitrogen co-doped lignin-based carbon catalysts to activate peroxymonosulfate for the degradation of bisphenol A

Mn-based catalysts have attracted widespread attention because of their low price, sufficient source and effective activation of peroxymonosulfate (PMS) to generate free radicals for rapid degradation of organic pollutants. In most pulp and paper industries, lignin sulfonates are usually the waste streams or serve as low-value fuels. However, lignin sulfonates due to its abundant aromatic structure and sulfur functional groups, is regarded as an excellent carbon resource. The stability of supported Mn-based catalyst can be improved by doping nitrogen atoms through the formation of covalent bonds. In this work, Mn, N co-doped carbon composites were prepared by one-step carbonization, and the catalysts were characterized by TEM, XRD, XPS, etc. and the results show that the catalysts with low Mn content mainly contain highly dispersed Mn species such as MnNx species, while high Mn loading catalyst includes some MnOx species. The catalytic performances of the catalysts were evaluated by the degradation of bisphenol A (BPA) by activating PMS, which can reach >95 % in 8 min. Catalyst recyclability experiments demonstrate that carbon-based materials have good stability without the remarkable leaching of metal ions during the degradation reaction. The results of radical capture experiments and radical-assisted ESR show that the active species of the reaction is non-free radical singlet oxygen (1O2), which can effectively degrade BPA. This study provides a facile and efficient method to prepare high-efficient Mn-N-C catalysts in the catalytic decomposition of BPA.

High Entropy Catalysts for Synthesis of Biofuels (C7–C17) via the Adjustable Carbon Chain Increasing of Furfural (C5) at Mild Temperature

High Entropy Catalysts for Synthesis of Biofuels (C₇–C₁₇) via the Adjustable Carbon Chain Increasing of Furfural (C₅) at Mild Temperature

Mass transfer enhancement and drying mechanism of high adhesion saturated impregnated Co-Al2O3 monolithic catalyst

The drying process significantly influences the dispersion of metals, physical properties, and performance of monolithic catalysts. In this research, a cordierite-based monolithic catalyst with Co/γ-Al2O3 was prepared using the slurry and impregnation method. The impact of ambient humidity on metal dispersion, mass transfer performance, and catalytic performance was investigated. The findings revealed distinct crystallization-deliquescence curves in the saturated impregnated monolithic catalysts, with alternating crystallization and deliquescence phenomena occurring as the ambient humidity changed. When the coating adhesion was high, the simultaneous occurrence of internal crystallization and surface dissolution resulted in concentrated internal stress, which facilitated the micro-stripping of the coating, leading to the formation of a cobweb-like microstructure. This process affected the distribution of pore sizes and enhanced mass transfer performance. The Co-based catalysts prepared in this study demonstrated a high selectivity for C5+ products (73.93%) when employed in the Fischer-Tropsch synthesis reaction. This research offers an optimization strategy for catalyst preparation, aiming to develop monolithic catalysts with low melting points, high crystallinity, and supersaturated supported transition metals.

A Highly Active and Reusable Multicomponent high Entropy Metal Oxide Catalyst for Nitroarenes Hydrogenation

It is well known that multicomponent catalysts can improve catalytic performance, however their rational design and precise control of catalytic activities by varying the composition of the elements is challenging. Herein, we present a facile and scalable synthetic strategy for production of senary and septenary metal oxide nanoparticles with a chemical composition of MSbOx and MSb2Ox (M: Fe, Ni, Co, Cu, and Zn). All samples were formed in a tetragonal crystal structure with space group 136 and crystallographic symmetry P42/mnm while the details of their constituent unit cells are different, belonging to rutile or trirutile structures. These nanocomposites have an oxygen vacancy-rich construction with uniform elemental distributions that produce various surface functionalities. They showed instantaneous hydrogenation catalytic performance for reduction of 4-nitrophenol to 4-aminophenol at room temperature. Among our samples, the senary catalyst with MSbOx chemical composition showed better durability and reusability owning to its morphological and microstructural properties. It showed 100% conversion of 4-nitrophenol to 4-aminophenol within 4 min at the 18th run without any by-products.

A self-supported 3D porous high entropy alloy with progressive formation of needle-shaped nanowires during reactions for maintained excellent electrocatalytic oxygen evolution

An efficient 3D porous bulk electrocatalyst is a feasible way to improve the conductivity. Herein, the preparation of a novel self-supporting 3D porous bulk FeCoNiMgB catalyst exhibits excellent electrocatalytic activity and stability properties towards OER. The self-supporting 3D porous framework structure catalyst possesses multiple advantages including large surface area, excellent conductivity, leading to the fast mass and charge transfers, low electrochemical impedance and fast water splitting reaction kinetics. As a result, the 3D porous bulk FeCoNiMgB catalyst requires substantially lower overpotential (234 mV) with a small Tafel slope (36.1 mV dec−1) as compared to pure FeCoNiMgB powders and RuO2 electrodes, as well as stable catalytic properties for over 72 h with no obvious evidence of degradation. Comparative structural characterization and DFT calculations reveal that the needle-shaped nanowires with Fe rich are formed from many open pores during the OER process, which helps to reduce the rate determining step energy barrier (O∗→OOH∗) for OER, and thus has excellent long-term electrochemical stability for continuous oxygen production under alkaline conditions. This work provides a new feasible and promising protocol to realize a novel self-supporting 3D porous bulk high entropy alloy catalyst as an inexpensive catalyst for efficient water splitting.

Low Catalyst Loading Enhances Charge Accumulation for Photoelectrochemical Water Splitting

AbstractSolar water oxidation is a critical step in artificial photosynthesis. Successful completion of the process requires four holes and releases four protons. It depends on the consecutive accumulation of charges at the active site. While recent research has shown an obvious dependence of the reaction kinetics on the hole concentrations on the surface of heterogeneous (photo)electrodes, little is known about how the catalyst density impacts the reaction rate. Using atomically dispersed Ir catalysts on hematite, we report a study on how the interplay between the catalyst density and the surface hole concentration influences the reaction kinetics. At low photon flux, where surface hole concentrations are low, faster charge transfer was observed on photoelectrodes with low catalyst density compared to high catalyst density; at high photon flux and high applied potentials, where surface hole concentrations are moderate or high, slower surface charge recombination was afforded by low‐density catalysts. The results support that charge transfer between the light absorber and the catalyst is reversible; they reveal the unexpected benefits of low‐density catalyst loading in facilitating forward charge transfer for desired chemical reactions. It is implied that for practical solar water splitting devices, a suitable catalyst loading is important for maximized performance.

Low Catalyst Loading Enhances Charge Accumulation for Photoelectrochemical Water Splitting.

Solar water oxidation is a critical step in artificial photosynthesis. Successful completion of the process requires four holes and releases four protons. It depends on the consecutive accumulation of charges at the active site. While recent research has shown an obvious dependence of the reaction kinetics on the hole concentrations on the surface of heterogeneous (photo)electrodes, little is known about how the catalyst density impacts the reaction rate. Using atomically dispersed Ir catalysts on hematite, we report a study on how the interplay between the catalyst density and the surface hole concentration influences the reaction kinetics. At low photon flux, where surface hole concentrations are low, faster charge transfer was observed on photoelectrodes with low catalyst density compared to high catalyst density; at high photon flux and high applied potentials, where surface hole concentrations are moderate or high, slower surface charge recombination was afforded by low-density catalysts. The results support that charge transfer between the light absorber and the catalyst is reversible; they reveal the unexpected benefits of low-density catalyst loading in facilitating forward charge transfer for desired chemical reactions. It is implied that for practical solar water splitting devices, a suitable catalyst loading is important for maximized performance.

Iodanyl Radical Catalysis.

ConspectusHypervalent iodine reagents find application as selective chemical oxidants in a diverse array of oxidative transformations. The utility of these reagents is often ascribed to (1) the proclivity to engage being selective two-electron redox transformations; (2) facile ligand exchange at the three-centered, four-electron (3c-4e) hypervalent iodine-ligand (I-X) bonds; and (3) the hypernucleofugacity of aryl iodides. One-electron redox and iodine radical chemistry is well-precedented in the context of inorganic hypervalent iodine chemistry─for example, in the iodide-triiodide couple that drives dye-sensitized solar cells. In contrast, organic hypervalent iodine chemistry has historically been dominated by the two-electron I(I)/I(III) and I(III)/I(V) redox couples, which results from intrinsic instability of the intervening odd-electron species. Transient iodanyl radicals (i.e., formally I(II) species), generated by reductive activation of hypervalent I-X bonds, have recently gained attention as potential intermediates in hypervalent iodine chemistry. Importantly, these open-shell intermediates are typically generated by activation of stoichiometric hypervalent iodine reagents, and the role of the iodanyl radical in substrate functionalization and catalysis is largely unknown.Our group has been interested in advancing the chemistry of iodanyl radicals as intermediates in the sustainable synthesis of hypervalent I(III) and I(V) compounds and as novel platforms for substrate activation at open-shell main-group intermediates. In 2018, we disclosed the first example of aerobic hypervalent iodine catalysis by intercepting reactive intermediates in aldehyde autoxidation chemistry. While we initially hypothesized that the observed oxidation was accomplished by aerobically generated peracids via a two-electron I(I)-to-I(III) oxidation reaction, detailed mechanistic studies revealed the critical role of acetate-stabilized iodanyl radical intermediates. We subsequently leveraged these mechanistic insights to develop hypervalent iodine electrocatalysis. Our studies resulted in the identification of new catalyst design principles that give rise to highly efficient organoiodide electrocatalysts that operate at modest applied potentials. These advances addressed classical challenges in hypervalent iodine electrocatalysis related to the need for high applied potentials and high catalyst loadings. In some cases, we were able to isolate the anodically generated iodanyl radical intermediates, which allowed direct interrogation of the elementary chemical reactions characteristic of iodanyl radicals. Both substrate activation via bidirectional proton-coupled electron transfer (PCET) reactions at I(II) intermediates and disproportionation reactions of I(II) species to generate I(III) compounds have been experimentally validated.This Account discusses the emerging synthetic and catalytic chemistry of iodanyl radicals. Results from our group have demonstrated that these open-shell species can play a critical role in sustainable synthesis of hypervalent iodine reagents and play a heretofore unappreciated role in catalysis. Realization of I(I)/I(II) catalytic cycles as a mechanistic alternative to canonical two-electron iodine redox chemistry promises to open new avenues to application of organoiodides in catalysis.

Removal of humic acid by peroxymonosulfate active with MnOx from the backwashing sludge of a filter for manganese removal

Finding a low-cost and high effective catalyst is an important problem in advanced oxidation processes (AOPs) based on PMS for organic matter removal. In this study, manganese oxide (MnOx) was extracted from the backwashing sludge of a filter for manganese removal and used to activate peroxymonosulfate (PMS) to remove humic acid from water. It was found that thermal treatment had significant effects on the structure and catalytic activity of MnOx. When MnOx was treated at 500 °C, it showed excellent catalytic activity and the removal rate of HA was up to 81.0%. Characterization indicated that the MnOx was converted from buserite and birnessite to α-MnOx after treated at 500 °C, and the specific surface area and the percentage of Mn (III) and Olatt on the surface increased significantly. The repeated utilization experiments indicated that the extracted MnOx still had high activity after reusing for 5 cycles. Quenching experiments showed that 1O2 was the dominant reactive oxygen species to oxidize HA in water. Finally, combining the results of FTIR and XPS spectra of MnOx before and after the catalytic reaction, the reaction mechanism was proposed: PMS was activated to be 1O2 by Mn (III) and Olatt in MnOx with a valence transformation between Mn (II), Mn (III) and Mn (IV) and HA was mainly oxidized by the non-radical pathway through 1O2. The experiments will provide a new strategy for recycling MnOx from backwashing sludge of the filter for Mn2+ removal to remove natural organic matter from water.

Efficient non-catalytic depolymerization of lignin in hydrogen donor solvent for monomeric phenols and its pathways

Thermal degradation of lignin in hydrogen donor solvent (HDS) has been reported to be an efficient method to generate aromatics and phenols. High pressure H2 and catalyst are not required which simplifies this degradation method. This work aims to advance the knowledge of reaction pathway with depolymerization of enzymatic hydrolysis lignin (EHL) in 9,10-dihydroanthracene (DHA) as an example. For this purpose, the liquid products were characterized in detail by GC, GPC, 31P NMR and 2D-HSQC NMR. Results indicate that the yield of monomeric phenols is up to 20.2 wt% at 375–400 °C. This yield is comparable to literature results with high-pressure H2 and catalysts at 220–320 °C. The depolymerization starts with the cleavage of ether linkages and decarboxylation of acrylate linkages, which are followed by the removal of aliphatic-OH, hydrogenation of Cal = Cal, decarbonylation of Cal = O, dealkylation of alkyl substituents and demethylation of aromatic-methoxy groups. The amount of phenolic-OH is about 2.78 mmol/g in the liquid product obtained at 400 °C: 36% from the cleavage of β-O-4 and α-O-4 linkages and about 16% from the demethylation of aromatic-methoxy group. The number-average molecular weight is roughly inversely proportional to the amount of bond cleavage.

A new high efficiency catalyst of Co–Ni/CeO2 for hydrogen production by ammonia oxidative decomposition at low temperature

Hydrogen production through ammonia decomposition at high temperatures is a promising approach, but lacks a simple and cost-effective process for efficient and rapid initiation of ammonia decomposition without external energy. To address this, the preparation of nanomaterials is crucial to achieve excellent ammonia oxidative decomposition performance. In this study, CeO2 with an ordered mesoporous structure was synthesized and supported with Co and Ni bimetals using a co-deposition method. Through various experimental characterization methods (XRD, BET, TEM, H2-TPR and XPS), a structure-activity relationship was established and a catalytic reaction mechanism was proposed. The catalyst with the best activity performance was found to be 5 wt % Co-5wt % Ni/CeO2 (CNC-55). With an NH3/O2 ratio of 4:1, the reaction temperature increased rapidly from 130 °C to 570 °C, the NH3 and O2 conversion rate can reach 95% and 100% respectively, and the H2 production rate can reaches 62%. The catalyst also exhibited good stability and reusability. Notably, the process only required ammonia and oxygen at low temperatures to produce hydrogen, nitrogen and water vapor, without the need for external energy or additional procedures.

Copper(I)-BOX Catalyzed Asymmetric 3-Component Reaction for the Synthesis of Trifluoromethylated Propargylic Ethers and Anilines.

An asymmetric 3-component reaction between EthynylBenziodoXoles (EBXs), 2,2,2-trifluorodiazoethane and nucleophiles catalyzed by a Cu(I)-BOX (Bisoxazoline) catalyst is described. This protocol gives access to chiral trifluoromethylated propargyl ethers and anilines, which are valuable building blocks in synthetic and medicinal chemistry. The reaction proceeds with high enantioselectivity and yield with different nucleophiles such as primary, secondary and tertiary alcohols, as well as both electron-rich and electron-poor anilines. Aryl-, alkyl- and silyl-substituted alkynes can be successfully introduced as electrophiles. In case of chiral substrates, high catalyst control was observed, leading to good diastereoselectivity.

Copper (I)‐BOX Catalyzed Asymmetric 3‐Component Reaction for the Synthesis of Trifluoromethylated Propargylic Ethers and Anilines**

AbstractAn asymmetric 3‐component reaction between EthynylBenziodoXoles (EBXs), 2,2,2‐trifluorodiazoethane and nucleophiles catalyzed by a CuI‐BOX (Bisoxazoline) catalyst is described. This protocol gives access to chiral trifluoromethylated propargyl ethers and anilines, which are valuable building blocks in synthetic and medicinal chemistry. The reaction proceeds with high enantioselectivity and yield with different nucleophiles such as primary, secondary and tertiary alcohols, as well as both electron‐rich and electron‐poor anilines. Aryl‐, alkyl‐ and silyl‐substituted alkynes can be successfully introduced as electrophiles. In case of chiral substrates, high catalyst control was observed, leading to good diastereoselectivity.

CO2 reduction performance of Cu/Er supported on N-doped graphene: A first principles study

A high atomic utilization and excellent catalytic activity distinguish atomic dispersion catalysts from the others, which are frequently utilized in CO2 reduction. Compared with single-atom catalysts (SACs), diatomic catalysts (DACs) have more dispersed active sites and different electronic structures, which could show different catalytic properties. Here, the CO2 reduction reaction (CO2RR) to C1 products process was systematically investigated for five different graphene-supported catalysts, including monatomic CuNC and ErNC, diatomic CuNC-ErNC, CuErNC-I, and CuErNC-II, using first principles calculations. Their free-energy diagrams were created, and the limit-potential /overpotential of different products were determined. It was shown that the minimum overpotential for CO2RR to CO/CH4 was 0.28/0.91 V on CuErNC-I(Er), to HCOOH was 1.01 V on CuErNC-I(Cu/Er), and to CH3OH was 0.81 V on CuErNC-I(Cu), respectively. At the same time, CuErNC-I displayed better electrochemical activity than others, and CuNC-ErNC had high selectivity comparing CO2RR with hydrogen evolution reaction (HER). This work provided a successful example to design high performance and selectivity catalysts by anchoring metal dimers to N-doped graphene substrates.

Construction of high content CoMoS active sites through the combination of Co5Mo10 molecular precursors and inert carbon matrix support for deep hydrodesulfurization

The rational design of high sulfurization and abundant CoMoS active phases catalysts is the key to drive the industrialization of hydrodesulfurization (HDS). Herein, we prepared a nano-catalyst with well-dispersed and numerous CoMoS active sites through confining Co3(II)[Co2(III)Mo10O38H4] (Co5Mo10) polyoxometalates (POMs) molecules with high Co/Mo ratio in hollow mesoporous carbon spheres (HMCS). On the one hand, POMs acted as pre-assembled molecular platform can build and regulate the structure of active phases by precisely adjusting the Co/Mo atomic ratio at molecular level. Meanwhile, the intimate interaction of Co-Mo on the POMs precursor also ensures that the Co species mainly exists as Co-promoted MoS2 active phase after the sulfidation process, thus the highly efficient synergism of the bimetals can be fully utilized in the reaction. On the other hand, the mesoporous carbon sphere with homogeneous pore size and high specific surface area can effectively confine the growth of the catalyst to disperse the active metals. The weakening metal–metal interaction property of such inert support enables the S-Co5Mo10/HMCS-10 catalyst to realize higher sulfurization, shorter slab length and higher stacking number. In addition, the abundant mesopores and high pore capacity of support greatly facilitate the mass transfer process and provide sufficient space for the HDS reaction as the nanoreactor. The unique combination of POMs and HMCS enabled the S-Co5Mo10/H10 catalyst to achieve up to 99.2% conversion of dibenzothiophene (DBT) after 4 h of HDS reaction, while obtaining a TOF value of 1.3 × 10−3 s−1 (calculated when keeping the low conversion at 42% after 0.5 h of reaction). The structural orientation of the POMs precursors to the active phases of HDS catalysts was investigated using various characterization methods, and the structure–activity relationship between the catalytic performance and the sulfide active phases was also revealed in this work.

Green Synthesis and Study of Biological Activity of New Spiropyrrolooxindoles Using Ag@KF/Clinoptilolite Nanoparticles as Catalyst

This study looked into the high yield production of new spiropyrrolooxindole derivatives. In order to create these new compounds, a multicomponent reaction involving isatin, malononitrile, alkyl 2,4-dioxo-4-(arylamino) butanoate derivatives, primary amines, and ethyl bromopyruvate was carried out in water at room temperature with catalytic amounts of Ag@KF/CP NPs acting as a high performance catalyst. The antioxidant property of new synthesized spiropyrrolooxindoles are owing to having NH group which was evaluated by two procedures. Also, the antimicrobial activity of new generated spiro isatins was evaluated by disk distribution process utilizing two kinds of Gram-negative bacteria and Gram-positive bacteria; proving bacterial growth was stopped by using of these compounds. Also, the catalytic activity of the green synthesized Ag@KF/CP NPs was evaluated in the reduction of organic pollutants such as 4-nitrophenol (4-NP) in water at mild conditions. The results indicated that the biosynthesized NCs have very high and effective catalytic activity for organic pollutants within few seconds. Applied to the preparation of spiropyrrolooxindole derivatives, this method has short reaction times, high product yields, and the ability to separate catalyst and product using simple procedures.

Exploring microstructure of MgCl2·nEtOH adducts for Ziegler-Natta catalysts

The activation of MgCl2 through the formation of MgCl2·nEtOH adducts is considered the principal step for the preparation of high performance Ziegler-Natta catalysts for olefins polymerizations in industry. Despite this importance, due to the complicated microstructure of the adducts, the precise structural characterization of these compounds has been left behind. In this research, four MgCl2.nEtOH adducts (with n = 0.6, 1.0, 1.8, and 3.2) were prepared by melt quenching procedure and assessed thoroughly by different techniques. Despite the multiple peaks in TGA analysis, similar FTIR spectra were recorded, and the adducts with n = 3.2 revealed sticky nature in SEM pictures which enhanced their particle size and broadened SPAN. According to the XRD spectra, the adducts showed distinct peaks related to the lateral cuts of distorted MgCl2, in which the ratio of α-MgCl2 to β-MgCl2 form enhanced by increasing the EtOH content, that was further confirmed by DFT calculations, even though it must be accepted that it is only a minimalist exercise in terms of a clear characterization of the adducts.

Utilizing High Entropy Effects for Developing Chromium‐Tolerance Cobalt‐Free Cathode for Solid Oxide Fuel Cells

AbstractSolid oxide fuel cell (SOFC) is regarded as an environmentally friendly energy conversion device, which can directly convert the chemical energy stored in the fuel to the electrical energy. However, the degradation of cathodes caused by Cr‐containing steel interconnects is a major problem that limits the broader application of SOFC. Herein, a novel A‐site high entropy oxide, based on the cobalt‐free PrBaFe2O5+δ (PBF) cathode, La0.2Pr0.2Nd0.2Sm0.2Gd0.2BaFe2O5+δ (LPNSGBF), is proposed as a high catalyst activity and Cr‐tolerance cathode for SOFC. The anode‐supported cell with the LPNSGBF cathode exhibits an excellent peak power density of 1020.69 mW cm−2 at 800 °C, which is better than that of the PBF (794.96 mW cm−2). Moreover, under the Cr‐containing atmosphere, the outstanding stability of the single cell with the LPNSGBF for 100 h with a degradation rate of 0.17% h−1, is much lower than the 0.79% h−1 for that of the PBF cathode. The study provides a new strategy for achieving the enhanced oxygen reduction reaction and high Cr‐tolerance of the cobalt‐free cathode by high entropy doping.

One-Step Synthesis of a High Entropy Oxide-Supported Rhodium Catalyst for Highly Selective CO Production in CO2 Hydrogenation.

High entropy oxide (HEO) has shown to be a new type of catalyst support with tunable composition-function properties for many chemical reactions. However, the preparation of a metal nanoparticle catalyst supported on a metal oxide support is time-consuming and takes multiple complicated steps. Herein, we used a one-step glycine-nitrate-based combustion method to synthesize highly dispersed rhodium nanoparticles on a high surface area HEO. This catalyst showed high selectivity to produce CO in CO2 hydrogenation with 80% higher activity compared to rhodium nanoparticle-based catalysts. We also studied the effect of different metal elements in HEO and demonstrated that high CO selectivity was achieved if one of the metals in the metal oxide support favored CO production. We identified that copper and zinc were responsible for the observed high CO selectivity due to their low *CO binding strength. During hydrogenation, a strong metal-support interaction was created through charge transfer and formed an encapsulated structure between rhodium nanoparticles and the HEO support to lower the *CO binding strength, which enabled high CO selectivity in the reaction. By combining different metal oxides into HEO as a catalyst support, high activity and high selectivity can be achieved at the same time in the CO2 hydrogenation reaction.