Catalysts For Conversion Research Articles

Unravelling the potential of prussian blue analogues in oxygen electrocatalysis: A perspective on surface reconstruction

Prussian blue analogues (PBAs) hold promises as catalysts for electrochemical energy conversion, especially in the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). Their high surface area and porosity combined with a tunable electronic structure featuring abundant metallic centers, make them attractive alternatives to traditional noble metal-based catalysts. Amongst these fascinating properties, the capacity for surface reconstruction to form active layers is one of the most sought-after characteristics of PBAs for enhanced activity. Recent advancements in operando and in situ techniques have further highlighted PBAs' capability for surface reconstruction during the electrocatalysis, particularly in alkaline solutions. State-of-the-art strategies for enhancing activity and stability of PBA-based catalysts, such as metal doping, tuning metal centers, introducing coordination sphere vacancies (VFeCN), and utilizing carbon supports, are closely linked to their ability towards surface reconstruction. However, key aspects warrant further exploration to achieve high electrocatalytic activity, including identifying initiators and pathways for surface reconstruction, establishing structure-property-activity correlations, and strategically manipulating in-situ catalyst surface reconstruction. This perspective focuses on understanding the transformation of PBA-based pre-catalysts to surface active layers on catalysts via surface reconstruction. A recent progress in PBA-catalysts towards advancing the electrochemical energy systems is highlighted. This perspective will guide the new entrants in the field to understand the process of surface transformation for establishing structure-property-activity relationships and thus to develop highly efficient PBA-based electrocatalysts.

Precisely Regulating Asymmetric Charge Distribution by Single-Atom Central Doped Ag-Based Series Clusters for Enhanced Photoreduction of CO2 to Alcohol Fuels.

High efficiently photocatalytic CO2 reduction (CO2RR) into liquid fuels in pure water system remains challenged. Iron polyphthalocyanine (FePPc) with strong light harvesting, unique Fe-N4 structure, abundant pores, and good stability could serve as a promising catalyst for CO2 photoreduction. To further improve the catalytic efficiency, herein, symmetry-breaking Fe sites are constructed by coupling with atomically precise M1Ag24 (M=Ag, Au, Pt) series clusters. Especially, the introduction of Pt1Ag24 causes the most asymmetric charge distribution of Fe in FePPc (followed by Au1Ag24 and Ag25), leading to the favorable CO2 adsorption and activation. In addition, Pt1Ag24-FePPc exhibits the most effective photogenerated carriers transfer and separation. As a result, Pt1Ag24-FePPc shows the methanol/ethanol yield of 48.55/32.97 μmol·gcat-1·h-1 in H2O-CO2 system under visible light irradiation, ~ 1.65/1.25-fold, 1.83/1.37-fold, and 3.6/1.61-fold higher than that of Au1Ag24-FePPc, Ag25-FePPc, and FePPc, respectively. This work provides a concept for precisely construction and regulation symmetry-breaking sites of cluster-based catalysts for effective CO2 conversion.

Revealing the nontrivial topological surface states of catalysts for effective photochemical carbon dioxide conversion

Topological semimetals with protected surface states mark a new paradigm of research beyond the early landmarks of band-structure engineering, allowing fabrication of efficient catalyst to harness the rich metallic surface states to activate specific chemical processes. Herein, we demonstrate a facile solid-phase method for in-situ doping of Ir at the Os sites in the Os3Sn7, an alloy with topological states, which significantly improves the photocatalytic performance for the reduction of CO2 to CO and CH4. Experimental evidence combined with theoretical calculations reveal that the nontrivial topological surface states greatly accelerate charge-separation/electron-enrichment and adsorption/activation of CO2 molecules, rendering highly efficient reaction channels to stimulate the formation of *COOH and *CO, as well CHO*. This work shows the promise of achieving high photocatalytic performances with synthesizing topological catalysts and provides hints on the design of novel topological catalysts with superior photoactivity towards the CO2 reduction reaction.

Bottom-up fabrication of DABCO-based bicationic ionic liquid-grafted MIL-101(Cr): Facilitating simultaneous activation of CO2 and epoxides for cyclic carbonate synthesis

Efficient activation of substrates as an orthogonal pathway for facilitating CO2 fixation into cyclic carbonates, poses ongoing challenges for the ingenious design and development of heterogeneous cooperative catalysts. Herein, a bottom-up strategy was employed to stepwise graft chloromethyl, triethylenediamine (DABCO), and chloroethylamine onto the organic linkers, forming bicationic ionic liquid tethered to MIL-101(Cr). The introduced –NH2 and quaternary ammonium groups dangling within the micro-mesopores ensured the fast enrichment and polarization of CO2 molecules, while the inherent unsaturated Cr3+ sites bonded with the epoxides to promote the simultaneous activation. The ample Cl- counter-anions further nucleophilically attacked to proceed the ring opening process, triggering an upgradation in catalytic performance for cycloaddition. After optimized by the response surface methodology (RSM), a chloropropene carbonate (CPC) yield of 97.8 % with a selectivity of 99.3 % were attained over the developed Cl[TNH2]Cl@MIL-101(Cr) at mild conditions (104.5 °C, 1.07 MPa, 3.75 wt% of catalyst, 1.91 h) in the absence of any solvent or co-catalyst. Furthermore, Cl[TNH2]Cl@MIL-101(Cr) displayed good durability, universality, and recyclability. The synergy of multiple sites was testified by the in-situ DRIFTS spectra and DFT calculations, and thus the potential catalytic mechanism was deduced. The implement of this work could shed some lights on the rational assembling of robust IL@MOFs nanocomposites and offered novel avenues for the fabrication of high-efficiency catalysts for practical CO2 conversion.

Dicationic ionic liquid‐grafted UiO‐66 as efficient catalyst for CO2 conversion into cyclocarbonate under cocatalyst‐free and solventless conditions

CO2 chemical fixation offers a feasible approach for carbon mitigation and high‐value utilization, but it is still challenging to develop an efficient catalyst for CO2 conversion into cyclic carbonate. Herein, the triethylenediamine‐derived dicationic ionic liquids (DIL‐X, X = Cl, Br, and I) were grafted into UiO‐66 linkers through self‐assembly of Zr4+ ions and the mixed ligands of terephthalic acid and DIL‐bearing dicarboxylic acid, resulting in UiO‐66‐DIL‐Xn, (n designated as molar amount of the feeding DIL‐X). Their catalytic performance was evaluated by the epoxide cycloaddition reaction in the absence of solvent and cocatalyst. Among them, the UiO‐66‐DIL‐Cl0.4 catalyst exhibited outstanding performance, with a chloropropene carbonate yield of 92% and a high selectivity of 99% under 0.1 MPa CO2 at 110 °C for 16 h. Its high activity could be ascribed to the cooperativity among Lewis acidity of MOF nodes, the enhanced CO2 absorption, and the strong nucleophilicity offered by halogen ions of ionic liquid‐modified MOF. Moreover, UiO‐66‐DIL‐Cl0.4 presented excellent recyclability and substrate extension. A potential catalytic mechanism for the epoxide‐CO2 cycloaddition into cyclic carbonate has been proposed. This work will shed light on the rational design of functionalized MOFs‐based catalysts for CO₂ utilization.

Zinc cations incorporated in Silicalite-1 zeolite assist in anchoring atomically dispersed platinum catalyst for boosted and robust propane dehydrogenation

The utilization of Pt-based catalysts in the catalytic conversion of propane to propylene (PDH) remains pivotal in industrial processes. However, the scarcity of Pt and its high cost necessitates innovative strategies to enhance Pt dispersion and catalytic performance. In this study, we present an approach involving the in-situ incorporation of Zn cations into Silicalite-1 (S-1) zeolite through one-pot hydrothermal synthesis, which facilitates the anchoring of atomically dispersed Pt atoms. The synthesized 0.5Pt/Zn@S-1 catalyst exhibits the dehydrogenation performance of 25 % propane for approximately 34.2 % propane conversion and 95.1 % propylene selectivity (propylene turnover rate of 14.2 s−1), coupled with robust stability of up to 60 h without distinct deactivation under a WHSV of 49.1 h−1. Comprehensive characterizations reveal the formation of atomically dispersed Pt-Zn catalytic sites. The Pt atoms are incorporated with the Zn cations and dense silanol nests. This unique configuration facilitates a synergistic effect between Pt and Zn for dehydrogenation.

CO2‐Hydrogenation to Methanol over CuO/ZnO Based Infiltration Composite Catalyst Spheres

Multiple active component catalysts for efficient conversion of CO2 to Methanol (MeOH) are synthesized through coating γ‐Al2O3 carrier spheres by incipient wetness impregnation method (IWI). The well‐known bimetallic Copper Oxide/Zinc Oxide (CuO/ZnO) are promoted in three steps, first by Cerium Oxide (CeO2), then additionally with Zirconium Oxide (ZrO2) and finally with Calcium Oxide (CaO) resulting in four carrier catalysts with high surface area and catalyst pore. Quaternary and quinary carrier catalysts promoted with moderate CeO2, ZrO2 in the quaternary (20% CZCZ) and additionally with CaO (20% CZCZC) in the quinary catalysts demonstrate high CO2‐conversion ratios (16.2% and 18.7%) and space time yields (0.51 and 0.47 gMeOH h‐1 gCatalyst‐1) at 5 MPa and 250 °C reactor temperature. The high conversion ratios (XCO2) and good methanol space‐time‐yields (STYMeOH) are attributed to enhanced copper dispersion and several multi metal oxide component interactions essential to enhance CO2‐activation and ‐conversion through the catalytic systems as well as very high overall surface area. Compared to related studies, the carrier catalysts show superior conversion rates, proving the effectiveness of the introduced multi‐component carrier catalyst and extending the understanding of infiltrate composites as possible large‐scale application alternatives to precipitated MeOH catalyst systems.

Silicon photocathode functionalized with osmium complex catalyst for selective catalytic conversion of CO2 to methane

Solar-driven CO2 reduction to yield high-value chemicals presents an appealing avenue for combating climate change, yet achieving selective production of specific products remains a significant challenge. We showcase two osmium complexes, przpOs, and trzpOs, as CO2 reduction catalysts for selective CO2-to-methane conversion. Kinetically, the przpOs and trzpOs exhibit high CO2 reduction catalytic rate constants of 0.544 and 6.41 s−1, respectively. Under AM1.5 G irradiation, the optimal Si/TiO2/trzpOs have CH4 as the main product and >90% Faradaic efficiency, reaching −14.11 mA cm−2 photocurrent density at 0.0 VRHE. Density functional theory calculations reveal that the N atoms on the bipyrazole and triazole ligands effectively stabilize the CO2-adduct intermediates, which tend to be further hydrogenated to produce CH4, leading to their ultrahigh CO2-to-CH4 selectivity. These results are comparable to cutting-edge Si-based photocathodes for CO2 reduction, revealing a vast research potential in employing molecular catalysts for the photoelectrochemical conversion of CO2 to methane.

Immobilizing Ordered Oxophilic Indium Sites on Platinum Enabling Efficient Hydrogen Oxidation in Alkaline Electrolyte.

Addressing the sluggish kinetics in the alkaline hydrogen oxidation reaction (HOR) is a pivotal yet challenging step toward the commercialization of anion-exchange membrane fuel cells (AEMFCs). Here, we have successfully immobilized indium (In) atoms in an orderly fashion into platinum (Pt) nanoparticles supported by reduced graphene oxide (denoted as O-Pt3In/rGO), significantly enhancing alkaline HOR kinetics. We have revealed that the ordered atomic matrix enables uniform and optimized hydrogen binding energy (HBE), hydroxyl binding energy (OHBE), and carbon monoxide binding energy (COBE) across the catalyst. With a mass activity of 2.3066 A mg-1 at an overpotential of 50 mV, over 10 times greater than that of Pt/C, the catalyst also demonstrates admirable CO resistance and stability. Importantly, the AEMFC implementing this catalyst as the anode catalyst has achieved an impressive power output compared to Pt/C. This work not only highlights the significance of constructing ordered oxophilic sites for alkaline HOR but also sheds light on the design of well-structured catalysts for energy conversion.

Conversion of sugars into methyl lactate over poly (ionic liquid)s functionalized Sn/beta zeolites

Methyl lactate (MLA) is a versatile high value platform chemical prepared from biomass carbohydrates, with widely application in the pharmaceutical, food, pesticide, and cosmetics. The current study presented a one-pot catalytic conversion of sugars to MLA over poly (ionic liquid)s functionalized Sn/Beta zeolites under mild conditions. The Sn/Beta zeolites were prepared by an impregnation method, followed by modification with poly (vinyl imidazole) ([PVIM]) via an in-situ free radical polymerization method. Dosages of polymer and Sn, calcination temperature, reaction temperature, catalyst amount, substrate concentration, and reaction times were optimized. Results showed that an MLA yield of 61.4 % was obtained over 3[PVIM]-Sn/Beta with complete conversion of fructose at 140 °C for 8 h. The physicochemical properties were characterized by XRD, BET, FTIR, CO-DRIFTS, NH3-TPD and pyridine-FTIR analysis, indicating the coexistence of Lewis and Brønsted acid sites. Finally, a possible reaction mechanism was proposed that the weak Lewis acidity of imidazole rings of [PVIM] effectively regulated the local microenvironment of active sites, thus promoting the interaction of the active sites with electronegative oxygens of sugars. This study can provide as a reference for the development of solid acid catalysts for the catalytic conversion of biomass to platform chemicals.

Psidium guajava (guava) leaves derived functional activated carbon as a heterogeneous catalyst for conversion of Jatropha curcas oil to biodiesel

Herein, we report the development of a highly efficient activated porous acid catalyst using Psidium guajava (guava) leaves as the precursor. The synthesis involved chemical activation with ZnCl2 and sulfonation with 4-benzenediazonium sulfonate, resulting in the AC-X-PhSO3H catalyst, optimized by varying ZnCl2 ratios (X = 1, 2, 3). Comparative characterization using BET, SEM, XRD, FT-IR, and TGA revealed that AC-2-PhSO3H, pyrolyzed at 500 °C, exhibited exceptional efficiency with a maximum surface area of 492.97 m²/g and a sulfur density of 4.23 wt%. Using AC-2-PhSO3H as the catalyst, we achieved a remarkable Jatropha curcas oil (JCO) conversion (98.3 ± 0.3 %) to biodiesel under optimized reaction conditions (20:1 methanol to oil molar ratio, 10 wt% catalyst loading, 100 °C, 50 min) and FAME content of 98.04 %, as confirmed by ¹H NMR spectroscopy. The estimated cost of biodiesel production was $0.87 per litre, largely due to the notable reusability of the catalyst (82.9 ± 0.2 % JCO conversion in the 6th run) without additional treatments, indicating significant commercial applicability and enhanced stability.

Metal-organic framework-derived base catalyst for conversion of dimethyl carbonate to glycerol carbonate

Glycerol carbonate (GLC) offers a range of benefits including biodegradability, versatility, and its potential for carbon capture and utilization. Base catalysts play a crucial role for GLC synthesis by facilitating the activation of reactants, enhancing nucleophilicity, accelerating reaction kinetics, and enabling catalyst regeneration. In this study, metal–organic framework (MOF) derived hybrid structure, CaO-MgO@Al2O3, was developed as a base catalyst to promote transesterification of glycerol with dimethyl carbonate (DMC) to form GLC. The results show that hydrothermal plus wet-impregnation routes formed the hybrid nanostructure with homogenously dispersed Ca, Mg and Al elements. Further, the synthesized catalysts showed significantly high specific surface area and basicity (2.656 mmol g−1). High selectivity (>99 %) and high GLC yield (96.2 %; 208.9 mmol g-cat−1) were achievable. This study demonstrated the rational design concept of MOF-derived hybrid structures used in the enhancement of base catalysis for transesterification of DMC to GLC, offering an effective solution with mild reaction conditions and high conversion.

A Study of the Effects of K-Modification and (Co, Ni, Fe)-Promotion on a Supported MoS2-Based Catalyst for Ethanol Conversion

A Study of the Effects of K-Modification and (Co, Ni, Fe)-Promotion on a Supported MoS₂-Based Catalyst for Ethanol Conversion

Revitalizing CO2 photoreduction: Fine-tuning electronic synergy in ultrathin g-C3N4 with amorphous (CoFeNiMnCu)S2 high-entropy sulfide nanoparticles for enhanced sustainability

Sustainability is a key issue in developing stable and efficient catalysts for solar-catalyzed CO2 conversion. The concept of structural stabilization by quenching the Gibbs free energy, which is achieved by increasing the configurational entropy level of the system, introduced high-entropy materials. However, because alloying immiscible multimetallic atoms into a unit system is still an arduous process, the potential of high-entropy materials has not yet been fully exploited. Surprisingly, although metal sulfide photocatalysts have an enviable reputation for CO2 photoreduction (CO2-PR) owing to their optical/electronic merits and more negative redox potential than other materials, the capability of high-entropy metal sulfides has been completely disregarded. Herein, an adaptable, self-templating metal alkoxide appropriately addresses the immiscibility of metallic constituents by the well-blended metal ions with polyalcohol in the metal glycerate. Consequently, (CoFeNiMnCu)S2 high-entropy metal sulfide nanoparticles (HEMS-Nps) were grown in situ on crossed ultrathin g-C3N4 (UCN) monolayers during the sulfidation of the metal glycerate. The as-synthesized HEMS-Np has a crystalline–amorphous structure, which is conducive to the acceleration of charge transfer to/from reaction sites, and a convincing orientation for CO2 adsorption. These features are combined with synergistic electronic multimetallic interactions, facilitating a heterogeneous valence electron distribution and atomic disorder. The CO2-PR power of the (CoFeNiMnCu)S2@UCN nanostructure was noticeable in realizing added-value products in both the liquid–solid (1063 µmol/g h of syngas and 250 µmol/g h of methane) and gas–solid phases (1883 µmol/cm2 h of syngas and 321 µmol/cm2 h of methane). To prove its utility, long-term and corresponding time-equivalent cycling experiments were conducted, demonstrating a highly stable system that endured for a long time. Overall, this approach simultaneously exploits the advantages of sulfide-based materials and high-entropy materials in stable structures to generate sustainable CO2-PR materials.

Photothermal CO2 conversion to ethanol through photothermal heterojunction-nanosheet arrays

Photothermal CO2 conversion to ethanol offers a sustainable solution for achieving net-zero carbon management. However, serious carrier recombination and high C-C coupling energy barrier cause poor performance in ethanol generation. Here, we report a Cu/Cu2Se-Cu2O heterojunction-nanosheet array, showcasing a good ethanol yield under visible–near-infrared light without external heating. The Z-scheme Cu2Se-Cu2O heterostructure provides spatially separated sites for CO2 reduction and water oxidation with boosted carrier transport efficiency. The microreactors induced by Cu2Se nanosheets improve the local concentration of intermediates (CH3* and CO*), thereby promoting C-C coupling process. Photothermal effect of Cu2Se nanosheets elevates system’s temperature to around 200 °C. Through synergizing electron and heat flows, we achieve an ethanol generation rate of 149.45 µmol g−1 h−1, with an electron selectivity of 48.75% and an apparent quantum yield of 0.286%. Our work can serve as inspiration for developing photothermal catalysts for CO2 conversion into multi-carbon chemicals using solar energy.

Laser-Induced Pd-PdO/rGO Catalysts for Enhanced Electrocatalytic Conversion of Nitrate into Ammonia.

Electrochemical reduction of nitrate to ammonia (eNO3RR) is proposed as a sustainable solution for high-rate ammonia synthesis under ambient conditions. The complex, multistep eNO3RR mechanism necessitates the use of a catalyst for the complete conversion of nitrate to ammonia. Our research focuses on developing a novel Pd-PdO doped in a reduced graphene oxide (rGO) composite catalyst synthesized via a laser-assisted one-step technique. This catalyst demonstrates dual functionality: palladium (Pd) boosts hydrogen adsorption, while its oxide (PdO) demonstrates considerable nitrogen adsorption affinity and exhibits a maximum ammonia yield of 5456.4 ± 453.4 μg/h/cm2 at -0.6 V vs reversible hydrogen electrode (RHE), with significant yields for nitrite and hydroxylamine under ambient conditions in a nitrate-containing alkaline electrolyte. At a lower potential of -0.1 V, the catalyst exhibited a minimal hydrogen evolution reaction of 3.1 ± 2.2% while achieving high ammonia selectivity (74.9 ± 4.4%), with the balance for nitrite and hydroxylamine. Additionally, the catalyst's stability and activity can be regenerated through the electrooxidation of Pd.

Theoretical investigation of CO2 hydrogenation to methanol catalyzed on Pd-Ga bimetallic catalysts: Insights into the effects of Ga in different coordination environments

Methanol is easy to store compared to other gaseous hydrogenation products. Moreover, it can be further converted to other advanced hydrocarbons, so the conversion of CO2 to methanol (CTM) is a promising reaction. PdGa bimetallic catalysts are candidate catalysts for CTM conversion, which can promote H spillover to the active site and react with adsorbed CO2. However, the role of Ga atom in PdGa bimetallic catalysts and the underlying mechanism of CTM are still unclear at the molecular level. In this work, Ga atom with different coordination environments CN3, CN4 and CN5 were obtained on the Pd(111), and three reaction mechanisms of CTM on different catalysts are systematic investigated. Changes in the coordination environments of the Ga atom affected the adsorption configurations of HCOOH*, HCO*, and H2CO*, among others. Three catalysts have similar superior pathways, and the order of CO2 reactivity is CN4 > CN3 > CN5. The PdGa bimetallic catalysts containing 4-coordinated Ga atom are proposed to be the ideal catalysts. We hope that the conclusions obtained can help understand the reasons for the outstanding reactivity and selectivity of CTM on PdGa bimetallic catalysts at the molecular level, and can provide some guidance for the design and development of high-performance bimetallic catalysts.

Metal Variance in Multivariate Metal-Organic Frameworks for Boosting Catalytic Conversion of CO2.

Developing efficient, low-cost, MOF catalysts for CO2 conversion at low CO2 concentrations under mild conditions is particularly interesting but remains highly challenging. Herein, we prepared an isostructural series of two-dimensional (2D) multivariate metal-organic frameworks (MTV-MOFs) containing copper- and/or silver-based cyclic trinuclear complexes (Cu-CTC and Ag-CTC). These MTV-MOFs can be used as efficient and reusable heterogeneous catalysts for the cyclization of propargylamine with CO2. The catalytic performance of these MTV-MOFs can be engineered by fine-tuning the Ag/Cu ratio in the framework. Interestingly, the induction of 10% Ag remarkably improved the catalytic efficiency with a turnover frequency (TOF) of 243 h-1, which is 20-fold higher than that of 100% Cu-based MOF (i.e., TOF = 10.8 h-1). More impressively, such a bimetallic MOF still exhibited high catalytic activity even for simulated flue gas with 10% CO2 concentration. Furthermore, the reaction mechanism has been examined through the employment of NMR monitoring experiments and DFT calculations.

Bimetal Oxides Anchored on Carbon Nanotubes/Nanosheets as High-Efficiency and Durable Bifunctional Oxygen Catalyst for Advanced Zn-Air Battery: Experiments and DFT Calculations.

To meet increasing requirement for innovative energy storage and conversion technology, it is urgent to prepare effective, affordable, and long-term stable oxygen electrocatalysts to replace precious metal-based counterparts. Herein, a two-step pyrolysis strategy is developed for controlled synthesis of Fe2O3 and Mn3O4 anchored on carbon nanotubes/nanosheets (Fe2O3-Mn3O4-CNTs/NSs). The typical catalyst has a high half-wave potential (E1/2 = 0.87V) for oxygen reduction reaction (ORR), accompanied with a smaller overpotential (η10 = 290mV) for oxygen evolution reaction (OER), showing substantial improvement in the ORR and OER performances. As well, density functional theory calculations are performed to illustrate the catalytic mechanism, where the in situ generated Fe2O3 directly correlates to the reduced energy barrier, rather than Mn3O4. The Fe2O3-Mn3O4-CNTs/NSs-based Zn-air battery exhibits a high-power density (153mW cm-2) and satisfyingly long durability (1650 charge/discharge cycles/550h). This work provides a new reference for preparation of highly reversible oxygen conversion catalysts.

Highly efficient acetylene semi-hydrogenation over Cun cluster stabilized Pd1 single-atom catalysts

The single-atom catalysts (SACs) with the maximum metal utilization efficiency exhibits the advantage of high ethylene selectivity compared with the cluster catalyst in the acetylene semi-hydrogenation reaction, however, the SACs also possess the disadvantages of poor activity and high-temperature stability. Thus, maintaining high reactivity and stability while achieving high ethylene selectivity faces a challenge. The coordination environment of the first metal atom is reasonably adjusted by coordinating with the second adjacent metal atom, which provides the possibility of stimulating the intrinsic reactivity of SACs and maintaining the atomic properties unchanged during the reaction. Here, we prepared Pd1-Cun/Al2O3 catalysts with palladium single-atom species (Pd1) and copper cluster species (Cun) loaded on Al2O3 support by combining “anchoring” and “site isolation”, which effectively prevented the Pd1 transition to Pd cluster species (Pdn) during the reaction process while improving the activity of Pd1. The reaction evaluation results revealed that the activity of the Pd1-Cun/Al2O3 catalyst increased by 60 % compared with the Pd1/Al2O3 catalyst, and the stabilization time of ethylene selectivity (83 %) of Pd1-Cun/Al2O3 catalyst increased by > 100 h when the same conversion for both catalysts. The aberration-corrected high-angle annular dark-field scanning transmission electron microscopic (AC-HAADF-STEM), Diffuse reflectance Fourier transform infrared spectroscopy of CO adsorption (CO-DRIFTS) and X-ray photoelectron spectroscopy (XPS) showed that the “synergistic effect” of Cun and Pd1 is the main reason for the increase of reactivity, and the “site isolation” effect of Cun is a key factor in preventing the transition of Pd1 to Pdn. This method provides new research ideas for improving the activity of SACS and inhibiting the agglomeration of active centers.