Stereoselective Research Articles

Hydrogen Peroxide Electrosynthesis via Selective Oxygen Reduction Reactions Through Interfacial Reaction Microenvironment Engineering.

The electrochemical two-electron oxygen reduction reaction (2e- ORR) offers a compelling alternative for decentralized and on-site H2O2 production compared to the conventional anthraquinone process. To advance this electrosynthesis system, there is growing interest in optimizing the interfacial reaction microenvironment to boost electrocatalytic performance. This review consolidates recent advancements in reaction microenvironment engineering for the selective electrocatalytic conversion of O2 to H2O2. Starting with fundamental insights into interfacial electrocatalytic mechanisms, an overview of various strategies for constructing the favorable local reaction environment, including adjusting electrode wettability, enhancing mesoscale mass transfer, elevating local pH, incorporating electrolyte additives, and employing pulsed electrocatalysis techniques is provided. Alongside these regulation strategies, the corresponding analyses and technical remarks are also presented. Finally, a summary and outlook on critical challenges, suggesting future research directions to inspire microenvironment engineering and accelerate the practical application of H2O2 electrosynthesis is delivered.

Unsymmetric Protonation Driven Highly Efficient H2O2 Photosynthesis in Supramolecular Photocatalysts via One-Step Two-Electron Oxygen Reduction.

Photocatalytic hydrogen peroxide (H2O2) production has emerged as an attractive alternative to the traditional anthraquinone process. However, its performance is often hindered by low selectivity and sluggish kinetics of oxygen reduction reaction (ORR). Herein, we report an anthrazoline-based supramolecular photocatalyst, SA-SADF-H+, featuring an unsymmetric protonation structure for H2O2 photosynthesis from water and air.The introduction of unsymmetric protonation disrupts the initial mirror symmetry of SADF, significantly enhancing the molecular dipole and facilitating efficient charge separation and electron transfer. Additionally, this modification increases the hydrophilicity of SA-SADF-H+, enabling the interaction of water and dissolved oxygen with the catalytic sites. The altered electron density distribution creates numerous dual active sites for Yeager-type O2 adsorption, facilitating an efficient ORR towards H2O2 via a direct one-step two-electron pathway. Notably, SA-SADF-H+ achieves an outstanding photocatalytic H2O2 production at a rate of 4667 μmol L-1 h-1, with a remarkable solar-to-chemical conversion (SCC) of 1.35%, surpassing most organic photocatalytic systems. Furthermore, SA-SADF-H+ demonstrates remarkable photocatalytic antibacterial activity, achieving 100% antibacterial efficiency against Staphylococcus aureus within 60 min.

Impact of Transition-State Aromaticity on Selective Radical-Radical Coupling of Triarylimidazolyl Radicals.

Radical coupling reactions are generally known to have a low selectivity due to the high reactivity of radicals. In this study, high regio and substrate selectivity was discovered in the dimerization of triarylimidazolyl radicals (TAIR), a versatile photochromic reaction. When two different radicals, 2-(4-cyanophenyl)-4,5-diphenyl-1H-imidazolyl radical (CN-TAIR) and 2-(4-methoxyphenyl)-4,5-diphenyl-1H-imidazolyl radical (OMe-TAIR), were simultaneously generated in situ, a hexaarylbiimidazole, formed by selective coupling at the nitrogen atom at position 1 of CN-TAIR and the carbon atom at position 2 of OMe-TAIR, was isolated with high selectivity as the main product among 24 possible radical dimer hexaarylbiimidazole derivatives. This high regio and substrate selectivity cannot be explained solely by the stability of the product and/or the electrophilicity and nucleophilicity of the radicals but originates from the aromaticity of the transition state in the radical-radical coupling reaction. To date, the selectivity of radical coupling reactions has been thought to be controlled by steric hindrance and radical spin density, but this study revealed a new factor for controlling radical coupling, that is, transition-state aromaticity. Aromaticity has been reported to have an important effect not only in the reactivity and structure of ground-state molecules but also on the electronically excited states and transition states in pericyclic reactions such as the Diels-Alder reaction and the Cope-Claisen rearrangement. This study demonstrated for the first time that radical coupling reactions can also be controlled by transition-state aromaticity.

Synthesis of Pentafluorosulfanylated Ynamides and Further Functionalizations.

Herein is described the first synthesis of SF5-ynamides, versatile building blocks featuring the pentafluorosulfanyl motif. This synthesis proceeds through a two-step sequence of radical SF5-addition onto the π-system of a wide range of terminal ynamides and derivatives substituted with various nitrogen fragments followed by a dehydrochlorination reaction. A selection of downstream functionalization reactions, including nucleophilic additions, cycloadditions, and sulfur ylide synthesis, highlights the wide-ranging applications of this novel type of functionalized SF5-building block.

Solvent-free direct aerobic photocatalytic ammoxidation of benzyl alcohol to benzonitrile on In2O3/Au/POCN

Direct ammoxidation of alcohol to nitrile is an important reaction in organic synthesis but it is still challenge to achieve under mild condition and in absence of solvent. In the present work, a three-component Z-scheme In2O3/Au/POCN heterojunction photocatalyst with Lewis acid site and Au as electron bridge was constructed and was employed to achieve aerobic photocatalytic ammoxidation of benzyl alcohol to benzonitriles. For the first time, benzyl alcohol can be successfully photocatalyzed to benzonitrile under solvent-free conditions. The yield of benzonitrile can reach 93.5 % with a formation rate of 15344 μmol‧g−1‧h−1. To the best of our knowledge, the formation rate and selectivity of the present photocatalytic system at room temperature without solvent are higher than that of solvent-based photocatalytic systems. The effect of water produced during the solvent-free oxidation process was revealed to be unfavorable for activity and selectivity of the entitle reaction and the photocatalytic mechanism was proposed. Moreover, various aromatic (hetero) alcohols can photocatalyzed to the corresponding nitriles with satisfied yield over In2O3/Au/POCN.

Flexible Triboelectric Nanogenerators Based on Cadmium Metal-Organic Framework/Eethyl Cellulose Composites as Energy Harvesters for Selective Photoinduced Bromination Reaction.

The fabrication of self-driven systems with flexibility and tunable output for organic photoinduction is highly desirable but challenging. In this study, a 3D cadmium metal-organic framework (Cd-MOF) is synthesized and used as a filler for ethyl cellulose (EC) to create mechanically durable and flexible Cd-MOF@EC composite films. Due to its well-established platform with periodically precise structure nature, the outputs of Cd-MOF-based TENG are much higher than those of ligand-based TENGs. Furthermore, composite films with different doping ratios of Cd-MOF are employed to assemble Cd-MOF@EC-based triboelectric nanogenerators (TENGs). The results reveal that a doping ratio of 10 wt.% Cd-MOF in Cd-MOF@EC provides the highest TENG output. Subsequently, a flexible 10 wt.% Cd-MOF@EC-based TENG (FCEC-TENG), working in the contact-separation model, is constructed to harvest mechanical energy from the human body, demonstrating excellent output performance and stability. The energy harvested from FCEC-TENG can directly illuminate 14 commercial white light-emitting diodes (LEDs), providing visible light for the photoinduction of the bromination reaction, and generating bromide with good yield and tolerance. This study presents an effective method for constructing flexible MOF-based TENG for self-powered photoinduced organic transformation systems.

Controlling Hydrogen Evolution and CO2 Reduction at Transition Metal Hydrides.

ConspectusFuel-forming reactions such as the hydrogen evolution reaction (HER) and CO2 reduction (CO2R) are vital to transitioning to a carbon-neutral economy. The equivalent oxidation reactions are also important for efficient utilization in fuel cells. Metal hydride intermediates are common in these catalytic and electrocatalytic processes. Guiding metal hydride reactivity is important for achieving selective, kinetically fast, and low overpotential redox reactions. Our work has focused on understanding kinetic and thermodynamic aspects for controlling these reactive hydride species in an effort to design more selective electrocatalysts that operate at low overpotentials. Key to our research approach is understanding the free energy changes and rate of discrete steps of catalysis through the synthesis of proposed intermediates to independently investigate catalytic steps. Hydricity, the free energy of hydride dissociation, and how these values change with metal and ligand environment have informed catalyst design in the past few decades. We describe here how we have advanced upon these earlier studies.In our early studies we sought to understand solvent-dependent changes in hydricity for transition metal hydrides and how they impact the free energy for reduction of CO2 to formate (HCO2-). Additionally, we described how hydricity values can be applied to optimize HER and CO2R catalysis. This framework provides general guidelines for achieving selective CO2 reduction to formate without concomitant generation of H2. Kinetic information on steps in the proposed catalytic cycle of HER and CO2R catalysts were evaluated to identify potential rate-determining steps. As a second approach to achieve selective reduction for CO2, we explored two catalyst design strategies to kinetically inhibit HER using electrostatic (charged) and steric interactions. Hydricity values and other considerations for minimizing the free energy of proposed catalytic steps were also used to design an electrocatalyst for the interconversion between CO2 and HCO2- at low overpotentials. Further, we discuss our efforts to translate the CO2 hydrogenation activity of homogeneous catalysts to electrocatalysis.All of these catalytic systems operate with classical metal hydrides, where the electrons and proton are colocated on the metal center. However, classical metal hydrides all require very reducing potentials to generate sufficiently strong hydride donors for CO2 reduction. An analysis of metal hydride hydricity and reduction potentials shows that the strong correlation between reduction potential and hydricity is a general trend because the former is also highly correlated to pKa. However, formate dehydrogenase (FDH) generates a competent hydride donor at more mild potentials through bidirectional hydride transfer, where the proton and electrons of the hydride are not colocated. This bioinspired approach points to a promising new strategy for generating strong hydride donors at milder potentials and will surely open new avenues for using hydricity as a guide for addressing new and existing problems in catalysis.

Continuous Flow Chemistry and Bayesian Optimization for Polymer-Functionalized Carbon Nanotube-Based Chemiresistive Methane Sensors.

We report the preparation of poly(ionic) polymer-wrapped single-walled carbon nanotube dispersions for chemiresistive methane (CH4) sensors with improved humidity tolerance. Single-walled CNTs (SWCNTs) were noncovalently functionalized by poly(4-vinylpyridine) (P4VP) with varied amounts of a poly(ethylene glycol) (PEG) moiety bearing a Br and terminal azide group (Br-R1). The quaternization of P4VP with Br-R1 was performed using continuous flow chemistry and Bayesian optimization-guided reaction selection. Polymers (PyBrR1) with different degrees of functionalization were used to disperse SWCNTs and subsequently incorporated into sensors containing a platinum complex as an aerobic oxidative catalyst with a polyoxometalate (POM) redox mediator to facilitate room-temperature CH4 sensing. As the degree of quaternization in the PyBrR1-CNT composites increased, improvements in response magnitude were observed, with nominally 10% quaternized PyBrR1 giving the largest response. Incorporation of PEG improved sensor stability at relative humidities between 57-90% versus sensors fabricated from CNT dispersions with unfunctionalized P4VP. Devices fabricated with these dispersions outperformed those prepared in situ under dry conditions, and exhibited greater stability at elevated humidities. The influence of Keggin-type POM character was also evaluated to identify alternative POMs for enhanced sensor performance at high humidity. In an effort to identify areas for further improvement in algorithm performance for polymer functionalization, a kinetically informed machine learning model was explored as a route to predict reactivity of pyridine units and alkyl bromides under flow conditions.

Subtle Modifications in Interface Configurations of Iron/Cobalt Phthalocyanine-Based Electrocatalysts Determine Molecular CO2 Reduction Activities.

Strain engineering has emerged as a powerful approach in steering material properties. However, the mechanism and potential limitations remain poorly understood. Here we report that subtle changes in molecular configurations can profoundly affect, conducively or adversely, the catalytic selectivity and product turnover frequencies (TOFs) of CO2 reduction reaction. Specifically, introducing molecular curvature in cobalt tetraaminophthalocyanine improves the multielectron reduction activity by favorable *CO hydrogenation, attaining methanol Faradaic efficiency up to 52 %. In stark contrast, strained iron phthalocyanine exacerbates *CO poisoning, leading to decreased TOFCO by >50 % at -0.5 VRHE and a rapid current decay. The uniform dispersion is crucial for optimizing electron transfer, while activity is distinctly sensitive to the local atomic environment around the active sites. Specifically, local strain either enhances binding to intermediates or poisons the catalytic sites. Our comprehensive analysis elucidates the intricate relationship between molecular structure and activities, offering insights into designing efficient heterogeneous molecular interfaces.

Understanding the Reactivity and Selectivity of Oxazaborolidium Ion-Catalyzed Diels-Alder Reactions Involving Cyclobutenones as Dienophiles.

The poorly understood factors controlling the reactivity and selectivity (both stereo- and enantioselectivity) of catalyzed Diels-Alder reactions involving cyclobutenones as dienophiles have been analyzed in detail by means of Density Functional Theory calculations. To this end, the reactions with cyclopentadiene and furan as dienes and 3-(methoxycarbonyl)cyclobutenone catalyzed by Corey's chiral oxazaborolidium ion (COBI) have been selected and compared to their analogous uncatalyzed transformations. The combined Activation Strain Model of reactivity and Energy Decomposition Analysis methods have been used to quantitatively understand the acceleration and selectivity induced by the catalyst in this reaction.

Chalcogen Bonds Enable Efficient Photoreduction of Sulfur-Containing Heterocycles.

Chalcogen bonding interactions have attracted significant attention in a broad chemistry community, with a particular focus on their ability to stabilise the key transition states in various organic synthetic routes. In this work, we demonstrate that they can also be harnessed in selective photoredox reactions, which cannot be otherwise achieved with alternative approaches to photoreduction. We demonstrate this concept through the photoreduction of the sulfur-containing DNA nucleoside precursor thioanhydrouridine to 2'-deoxy-thiouridine, revealing the previously unrecognized role of bisulfide in this process. Based on quantum chemical simulations, we identify a stable chalcogen-bonding complex of the hydrosulfide anion and thionhydrouridine (HS-⋅⋅⋅S contacts), which enables directional photoinduced electron transfer, resulting in the formation of non-canonical DNA nucleoside. We also disprove the possibility that photoreduction of thioanhydronucleosides could be initiated by hydrated electrons generated from irradiated bisulfide anions which do not interact with the chromophore. Finally, we show that selective photoreduction mediated by chalcogen bonds can only occur for chromophores, which exhibit sufficiently long excited-state lifetimes in the locally-excited states to undergo transition to the productive charge transfer state. These findings can be further used in the design of similar photoredox reactions which can employ the potential of chalcogen bonding interactions.

Highly sensitive quantitation of N6-methyladenosine in long noncoding RNA at precise location with gap extension- and ligation-based loop-mediated isothermal amplification (GEXL-LAMP)

N6-methyladenosine (m6A), a post-transcriptional modification, is abundant in RNAs, plays prominent roles in various biological processes and is closely associated with human health. However, m6A functions remain largely unrevealed due to the lack of highly sensitive and selective techniques to quantify m6A at specific nucleotide positions, as distinguishing m6A from adenosine (A) is challenging. In this work, we have enhanced the selectivity for discriminating A from m6A by up to 265-fold by combining the polymerase selectivity for gap extension with the ligase selectivity for ligation reaction. With the ligation-based loop-mediated isothermal amplification (LAMP), we achieved ultrahigh sensitivity capable of detecting RNA molecules as low as 40 aM. Therefore, the proposed assay allows precise quantification of m6A modifications at one-nucleotide resolution.

Selective Hydrogen Oxidation Catalyst for PEM Fuel Cells: Tungsten Cluster-Tuned Platinum Single Atoms.

The selective hydrogen oxidation reaction (HOR) electrocatalyst is crucial for enhancing the performance of proton-exchange membrane fuel cells (PEMFCs) against degradation caused by reverse currents. In this study, a catalyst comprising platinum single atoms (Pt1) finely tuned by tungsten nanoclusters (WNC) on an accordion-like nitrogen-doped carbon support (ANC) is presented. The tungsten nanoclusters, derived from phosphotungstic acid, are embedded within the carbon support, while the Pt single atoms are uniformly dispersed on its surface. Experimental results and theoretical calculations reveal that the WNC effectively reduce the hydrogen adsorption strength on Pt1 to an optimal level, thereby facilitating HOR catalysis. Notably, this adjustment also weakens oxygen adsorption, rendering Pt1 less effective for catalyzing the oxygen reduction reaction. Consequently, the catalyst Pt1/WNC-ANC exhibits high resistance to degradation from reverse currents when oxygen leaks into the anode. Meanwhile, it demonstrates an ultralow HOR overpotential with an outstanding mass activity, 13 times greater than commercial Pt/C. This work provides a highly active and selective low-Pt HOR catalyst, paving the way for the development of cost-effective, long-lasting, and robust PEMFCs.

Preparation of lignin oil with high H content by electrolyzing alkali lignin pretreated by organic thiol/hydrogen peroxide /ethylene glycol

Pretreatment can improve the reaction selectivity of lignin, promote the subsequent electrolytic catalysis of lignin depolymerization and conversion into high-quality lignin oil, thereby enhancing the energy conversion efficiency of lignin. The degree of depolymerization and electrochemical reduction of lignin under different pretreatment methods was investigated in this study, it was found that ethylene glycol /hydrogen peroxide/β-mercaptoethanol can break β-O-4 bond in a mild condition to increase the depolymerization performance of lignin, and reduced its number-average molecular weight significantly. The effects of electrode material, reaction temperature and current density on the yield of lignin oil and volatile component content were discussed. The highest the yield of lignin conversion could reach 95.0 %, and small molecular products dominated by alkanes and aromatics were obtained, of which the monomer yield was 25.1 wt%, which could reduce the oxygen carbon ratio of lignin effectively, improve the calorific value of lignin oil (34.39 MJ/kg). This study will provide technical reference for the greenly and efficiently conversion of lignin into hydrocarbon fuels under milder conditions.

Selective hydroxylation of benzene via enhanced generation and utilization of hydroxyl radicals with CuZnSbO photocatalyst

Photocatalytic selective benzene hydroxylation via activation of C(sp2)–H under visible light remains a challenging reaction. Copper-incorporated mixed metal oxide photocatalysts have shown promise in addressing this difficulty by enabling visible light harvesting, controlled reactive oxygen species (ROS) generation, effective ROS utilization, and reactant adsorption. However, copper incorporated metal oxide catalysts were suffered from poor catalytic activity and selectivity due to leaching of Cu species. To solve this problem, herein, a novel stable mixed metal oxide (CuZnSbO) was prepared for the first time by applying a facile method. Copper introduction brought about the suitable band gap energy for a wide range of visible light harvesting of the CuZnSbO catalyst. The copper species play a key role in activating H2O2 to produce hydroxyl radicals (•OH) for benzene oxidation by controlling charge recombination. The mixed metal oxide of zinc and antimony supports the included copper strongly enabling copper stability. The CuZnSbO not only generates available hydroxyl radicals but also facilitates efficient hydroxyl radical consumption to initiate C(sp2)–H activation, forming benzene radical intermediates en route to phenol. That is ever reported. CuZnSbO delivered 31.51 % benzene conversion and 100 % phenol selectivity. This work demonstrates the promise of engineered mixed metal oxide that boosts Cu species utilization for H2O2 and benzene activation. The photocatalyst showed good activity in selective oxidative hydroxylation reactions through harnessing visible light and controlled ROS generation. Importantly, Cu cations govern the photocatalytic •OH generation mechanisms as shown by XPS and active site deactivation analysis.

Stoichiometry Dependence in the Consecutive, Competing Reduction, Halogenation, or Deoxygenation of Aryl Carbonyls.

Six fundamental chemical transformations of aryl carbonyls are achieved by properly adjusting the stoichiometry of the borane-amine and titanium tetrachloride reagent system. This set of reagents acts collectively as a hydride donor, Lewis acid catalyst, and halogen source for the reduction of carbonyls to alcohols, reductive halogenation of carbonyls to halides, deoxygenation of carbonyls to alkanes, dehydroxyhalogenation of alcohols to halides, deoxygenation of alcohols to alkanes, and hydrodehalogenation of halides to alkanes. While the carbonyl reduction is broadly applicable to both aromatic and aliphatic substrates, the remaining reactions are dependent on the stability of the proposed carbocationic intermediates, enabling highly selective reactions at the substrates' benzylic position. This unique selectivity allows benzylic dehalogenation in the presence of aryl and alkyl halides in addition to highly selective dehydroxyhalogenation of alcohols even for tertiary versus secondary aliphatic and secondary versus primary benzylic substrates using only titanium tetrachloride as the chlorinating agent.

Controlling the Selectivity of Reaction Products by Transmetalation on a Ag(111) Substrate.

On-surface synthesis has shown great promise in the precise bottom-up preparation of molecular nanostructures. Apart from the direct C-C coupling reaction pathway, an alternative strategy is to exploit the metal-organic interactions provided by integrated metals for preassembly, which exhibit high reversibility and can anchor specific conformations of molecular precursors, thus allowing the precise construction of nanostructures with improved reaction selectivity. Previous studies have mainly been devoted to the construction of target reaction products through the incorporation of metal atoms, ranging from intrinsic to extrinsic atoms on metal substrates and, more recently, to their cooperative effects. However, the formation of different covalent nanostructures by competitive interactions between intrinsic and extrinsic adatoms remains elusive. Herein, we controlled the selectivity of covalent reaction products from isomerically specific trans-chains to cis-rings, resulting from the transmetalation of intrinsic Ag adatoms to extrinsic Na atoms on a Ag(111) substrate. Our results exhibit the competitive interactions between intrinsic and extrinsic metal atoms in real space and demonstrate their influence on the selectivity of reaction products, which should broaden the regulatory strategies for on-surface synthesis that shed light on the controllable and selective synthesis of target covalent nanostructures.

Mechanistic insight into the catalytic activities of metallic sites on nitrogen-doped graphene quantum dots for CO2 hydrogenation

The origin of selectivity and activity of the CO2 hydrogenation reaction on single-atom catalysts composed of three adjacent 3d transition metals (Fe, Co, and Ni) supported on N-doped graphene quantum dots were systematically investigated and compared using density functional theory (DFT) calculations, natural bond orbital (NBO), and quantum theory of atoms in molecules (QTAIM) analysis. This study reveals that π-backbonding between the metal and CO2* does not occur and [CO2]δ+ species drive the reaction. The CO2* reacts with H2 via the Eley-Rideal (ER) mechanism by using the synergistic effects of the N site. The higher the partial positive charge on the C atom, the lower the Ea of the reaction. Subsequently, a tautomerization reaction, which is facilitated by hydrogen bonding, occurs and hydrogen is transferred to HCOO* resulting in the formation of CHOOH*. This study shows the selective formation of formic acid from CO2 is accessible on these SACs and Fe-SAC is the best one between these three catalysts. Although CO2 is more inert than formic acid the H2 molecule reacts with the adsorbed formic acid more difficult than the adsorbed CO2. It is because the hydrogenation of formic acid causes C-H bond formation resulting in failure of the coordinated O atom's octet and the unstable H2COOH* is formed. This step is the rate-determining step of HOCH2OH formation from CO2, with Ea of 1.94, 2.03, and 2.23 eV for Fe, Co, and Ni, respectively. Finally, the system undergoes another tautomerization reaction resulting in the formation of HOCH2OH (formaldehyde monohydrate).

Manipulating adsorbed hydrogen on lanthanum-modified CuOx: Industrial-current-density CO2 electroreduction to C2+ products or CH4

The selective electrochemical CO2 reduction reaction (CO2RR) yields valuable C2+ and C1 products, yet the influence of adsorbed hydrogen (*H) on product distribution remains inadequately understood. This study explores this effect by developing bimetallic copper-based electrocatalysts with varied lanthanum (La) doping ratios. The oxide-derived (OD)-La0.10-CuOx catalyst exhibits a Faradaic efficiency (FE) over 80% for C2+ products at 300 mA cm−2, whereas OD-La0.40-CuOx achieves a 61.4% FECH4 at 400 mA cm−2. Kinetic isotope experiments reveal distinct dependencies of the rate-determining steps on *H transfer for CO2RR in OD-La0.10-CuOx and OD-La0.40-CuOx. In situ ATR-SEIRAS and DFT calculations demonstrate that the moderate H2O dissociation capability of OD-La0.10-CuOx lowers the energy barrier for *CHO → *OCCHO conversion, thus increasing the FEC2+. Conversely, OD-La0.40-CuOx, with its strong H2O dissociation capability, favors *CHO → *CH2O, thereby promoting CO2RR-to-CH4. These findings advance the understanding of the role of *H in CO2 electroreduction at industrial current densities and present avenues for tailored CO2RR products via doping engineering.

Effectively regulating Ni distribution on CeO2 through formation of Ce1−xNixO2−y solid solution to enhance the selectivity in RWGS reaction

Nickel-based catalysts frequently encounter significant challenges in achieving both high CO2 conversion and superior CO selectivity during reverse water gas shift (RWGS) reactions. To address this issue, we developed a facile strategy to prepare highly dispersed Ni/CeO2 catalysts by forming Ce1−xNixO2−y solid solutions. Under conditions of 300–600 °C, 0.1 MPa, and a gas hourly space velocity (GHSV) of 40,000 mL gcat−1 h−1, the 5Ni/CeO2-A catalyst exhibited outstanding selectivity, approaching 100 %. The RWGS reaction rate reached 1332 μmolCO gNi−1 s−1 and maintained stable for 50 h almost without deactivation. The formation of Ce1−xNixO2−y solid solution uniformly disperses numerous Ni species in the CeO2 lattice, effectively inhibiting Ni aggregation. This highly dispersed Ni weakens CO adsorption and facilitates its direct desorption without excessive hydrogenation. Moreover, the catalyst remains well-dispersed state even after reduction. The formed Ce1−xNixO2−y solid solution generates abundant oxygen vacancies on the catalyst surface, enhancing H2 dissociation. The catalyst’s pore size distribution is also modified, creating stacked pores that favor reactant diffusion and expose more active centers. In-situ DRIFTS experiments demonstrate that Ce-OH plays a pivotal role in CO2 adsorption on the 5Ni/CeO2-A catalyst, while the stabilization of bicarbonate and formate intermediates by the highly dispersed Ni further promotes catalytic performance. This study introduces a novel preparation method and provides valuable insights for designing Ni-based catalysts with exceptional CO selectivity.