Reaction Energy Barrier Research Articles

Electric Field Redistribution Triggered Surface Adsorption and Mass Transfer to Boost Electrocatalytic Glycerol Upgrading Coupled with Hydrogen Evolution

AbstractElectrocatalytic glycerol oxidation reaction (GOR) stands out as an economical and prospective technology to replace oxygen evolution reaction for co‐producing high‐valued chemicals and hydrogen (H2). Regulating the adsorption of glycerol (GLY) and hydroxyl (OH) species is of great significance for improving the GOR performance. Herein, a hierarchical p–n heterojunction by combining Co‐metal organic framework (MOF) nanosheets with CuO nanorod arrays (CuO@Co‐MOF) is developed to realize the optimization on GOR. Specifically, CuO@Co‐MOF electrode exhibits superior performance with a conversion of 98.4%, formic acid (FA) selectivity of 87.3%, and Faradaic efficiency (FE) of 98.9%. The flow‐cell system with the bifunctional CuO@Co‐MOF electrode for pairing GOR with the hydrogen evolution reaction (HER) reveals better energy conversion efficiency. Experimental results and theoretical calculations unravel the redistributed electric field by introducing Co‐containing species that contribute to the improved performance, which not only enhances the OH adsorption but also modulates the excessive GLY adsorption of CuO, thus reducing reaction energy barriers of FA desorption. Simultaneously, finite element analysis reveals that the novelty hierarchical structure can increase the concentration of OH− and facilitate the mass transfer of OH− in the solution.

Effects of Electric Field on Chemical Looping Combustion: A DFT Study of CO Oxidation on CuO (111) Surface.

Chemical looping combustion (CLC) is a promising and novel technology for carbon dioxide (CO2) capture with a relatively low energy consumption and cost. CuO, one of the most attractive oxygen carriers (OCs) for carbon dioxide (CO) oxidation, suffers from sintering and agglomeration during the reduction process. Applying an electric field (EF) may promote the CO oxidation process on the CuO surface, which could mitigate sintering and agglomeration by decreasing operating temperatures with negligible combustion efficiency loss. This study performs density functional theory (DFT) simulations to investigate the effects of EF on the oxidation of CO on the CuO (111) surface. The results indicate that both the orientation and strength of the EF can significantly affect the oxidation characteristics of CO on the CuO (111) surface such as total reaction energy, energy barriers of reactions, CO adsorption, and CO2 desorption. For the first time, this study reveals the role of EF in enhancing CO oxidation through CLC processes via first-principle calculations. Such findings could provide new strategies to improve the performance of CLC processes.

Highly Curved Defect Sites: How Curvature Effect Influences Metal-Free Defective Carbon Electrocatalysts.

Topological defects are widely recognized as effective active sites toward a variety of electrochemical reactions. However, the role of defect curvature is still not fully understood. Herein, carbon nanomaterials with rich topological defect sites of tunable curvature is reported. The curved defective surface is realized by controlling the high-temperature pyrolytic shrinkage process of precursors. Theoretical calculations demonstrate bending the defect sites can change the local electronic structure, promote the charge transfer to key intermediates, and lower the energy barrier for oxygen reduction reaction (ORR). Experimental results convince structural superiority of highly-curved defective sites, with a high kinetic current density of 22.5mAcm-2 at 0.8V versus RHE for high-curvature defective carbon (HCDC), ≈18 times that of low-curvature defective carbon (LCDC). Further raising the defect densities in HCDC leads to the dual-regulated products (HCHDC), which exhibit exceptionally outstanding ORR activity in both alkaline and acidic media (half-wave potentials: 0.88 and 0.74V), outperforming most of the reported metal-free carbon catalysts. This work uncovers the curvature-activity relationship in carbon defect for ORR and provides new guidance to design advanced catalysts via curvature-engineering.

Amorphous Bismuth-Tin Oxide Nanosheets with Optimized C-N Coupling for Efficient Urea Synthesis.

Closing the carbon and nitrogen cycles by electrochemical methods using renewable energy to convert abundant or harmful feedstocks into high-value C- or N-containing chemicals has the potential to transform the global energy landscape. However, efficient conversion avenues have to date been mostly realized for the independent reduction of CO2 or NO3-. The synthesis of more complex C-N compounds still suffers from low conversion efficiency due to the inability to find effective catalysts. To this end, here we present amorphous bismuth-tin oxide nanosheets, which effectively reduce the energy barrier of the catalytic reaction, facilitating efficient and highly selective urea production. With enhanced CO2 adsorption and activation on the catalyst, a C-N coupling pathway based on *CO2 rather than traditional *CO is realized. The optimized orbital symmetry of the C- (*CO2) and N-containing (*NO2) intermediates promotes a significant increase in the Faraday efficiency of urea production to an outstanding value of 78.36% at -0.4 V vs RHE. In parallel, the nitrogen and carbon selectivity for urea formation is also enhanced to 90.41% and 95.39%, respectively. The present results and insights provide a valuable reference for the further development of new catalysts for efficient synthesis of high-value C-N compounds from CO2.

Catalytic mechanism of calcium ion on the NOx precursors formation during the pyrolysis of kitchen waste

Calcium ion (Ca2+) in kitchen waste exerts a significant impact on the formation of NOx precursors to affect the release of nitrogen oxides during the incineration process. However, the catalytic mechanism of Ca2+ is still unclear. Herein, 2,4-imidazolidinedione is employed as the nitrogen-containing model to study the effect of Ca2+ on the generation of NOx precursors during pyrolysis. Through density functional theory calculations (DFT) and wave function analysis of the catalytic effect of Ca2+, the results indicate that Ca2+ has different degrees of impact on the energy barriers of the initial ring opening reaction. Ca2+ not only changes the rate determining steps of NOx precursors formation pathways, but also reduces the total energy barriers formed by NH3. At the same time, the total energy barriers of all paths formed by HCN are raised. This work theoretically explains the phenomenon of Ca2+ promoting the formation of NH3, whereas inhibiting the release of HCN in pyrolysis experiments. In addition, Ca2+ promotes partial reaction pathways for the formation of HNCO, and the total energy barriers of catalytic pathways are lower than that of the uncatalyzed pathways. Therefore, under the catalysis of Ca2+, the generation pathway of HNCO is more competitive and it is conducive to the formation of HNCO.

Theoretical screening of electrocatalytic performance of Fe@BNC materials in lithium-sulfur batteries

Advanced cathode materials can suppress the shuttle effect and improve the slow sulfur reduction kinetics during discharge in lithium-sulfur batteries. The catalytic performance of Fe@BNC single-atom catalysts as cathode materials was evaluated through simulations based on density functional theory in this article. By calculating the Gibbs free energy curve and adsorption energy of polysulfides on the substrate, it was found that Fe@BNC has a reasonable adsorption energy range and good catalytic activity. Moreover, calculations of reaction energy barriers indicate that Fe@B1N3 performs well in delithiation when charged. The Research investigates in detail the electrocatalytic properties and electronic structure properties of Fe@BNC as a cathode material for lithium-sulfur batteries. This paper highlights its potential to improve battery performance by reducing the shuttle effect and accelerating the redox kinetics.

Neighbouring Synergy in High-Density Single Ir Atoms on CoGaOOH for Efficient Alkaline Electrocatalytic Oxygen Evolution.

The catalytic performance of single-atom catalysts was strictly limited by isolated single-atom sites. Fabricating high-density single atoms to realize the synergetic interaction in neighbouring single atoms could optimize the adsorption behaviors of reaction intermediates, which exhibited great potential to break performance limitations and deepen mechanistic understanding of electrocatalysis. However, the catalytic behavior governed by neighbouring single atoms is particularly elusive and has yet to be understood. Herein, we revealed that the synergetic interaction in neighbouring single atoms contributes to superior performance for oxygen evolution relative to isolated Ir single atoms. Neighbouring single atoms was achieved by fabricating high-density single atoms to narrow the distance between single atoms. Electrochemical measurements demonstrated that the Nei-Ir1/CoGaOOH with neighbouring Ir single atoms exhibited a low overpotential of 170 mV at a current density of 10 mA cm-2, and long-durable stability over 2000 h for oxygen evolution. Mechanistic studies revealed that neighbouring single atoms synergetic stabilized the *OOH intermediates via extra hydrogen bonding interactions, thus significantly reducing the reaction energy barriers, as compared to isolated Ir single atoms. The discovery of the synergetic interaction in neighbouring single atoms could offer guidance for the development of efficient electrocatalysts, thus accelerating the world's transition to sustainable energy.

Neighbouring Synergy in High‐Density Single Ir Atoms on CoGaOOH for Efficient Alkaline Electrocatalytic Oxygen Evolution

AbstractThe catalytic performance of single‐atom catalysts was strictly limited by isolated single‐atom sites. Fabricating high‐density single atoms to realize the synergetic interaction in neighbouring single atoms could optimize the adsorption behaviors of reaction intermediates, which exhibited great potential to break performance limitations and deepen mechanistic understanding of electrocatalysis. However, the catalytic behavior governed by neighbouring single atoms is particularly elusive and has yet to be understood. Herein, we revealed that the synergetic interaction in neighbouring single atoms contributes to superior performance for oxygen evolution relative to isolated Ir single atoms. Neighbouring single atoms was achieved by fabricating high‐density single atoms to narrow the distance between single atoms. Electrochemical measurements demonstrated that the Nei‐Ir1/CoGaOOH with neighbouring Ir single atoms exhibited a low overpotential of 170 mV at a current density of 10 mA cm−2, and long‐durable stability over 2000 h for oxygen evolution. Mechanistic studies revealed that neighbouring single atoms synergetic stabilized the *OOH intermediates via extra hydrogen bonding interactions, thus significantly reducing the reaction energy barriers, as compared to isolated Ir single atoms. The discovery of the synergetic interaction in neighbouring single atoms could offer guidance for the development of efficient electrocatalysts, thus accelerating the world‘s transition to sustainable energy.

Study on the mechanism of lignin and lignin-carbohydrate complex hydrolysis under alkaline conditions by density functional theory

Lignin hydrolyzes during alkali-heat pretreatment of lignocellulose, due to the cleavage of covalent linkages between lignin and lignin-carbohydrate complex. Various structure of lignin monomers are responsible of the complicated hydrolysis mechanism of lignin and lignin-carbohydrate complex. This study used density functional theory to reveal the hydrolysis mechanism of lignin with various substituents and lignin-carbohydrates complex with different linkages. The results indicated that the SN2 reaction was observed to take place in the lignin. Methoxy groups and methyl group had an insignificant influence on hydrolysis reaction pathway of lignin, whereas the presence of a methyl group on the α-carbon atom had a hindering effect on the nucleophilic attack during alkaline pretreatment. The lignin-carbohydrate complex with different linkage showed a significant difference in hydrolysis reaction pathway. Additionally, the reaction energy barrier of ester bond hydrolysis was lowest among the hydrolysis of ester bond, phenyl glycosidic bond, benzyl ether bond, γ-ester bond, coumarin ester bond and acetal bond under alkaline condition. This study provides valuable insights into the process control, reactor design, and performance enhancement for lignocellulose pretreatment.

A DFT Study of CO Hydrogenation on Graphene Oxide: Effects of Adding Mn on Fischer–Tropsch Synthesis

The hydrogenation of carbon monoxide (CO) offers a promising avenue for reducing air pollution and promoting a cleaner environment. Moreover, by using suitable catalysts, CO can be transformed into valuable hydrocarbons. In this study, we elucidate the mechanistic aspects of the catalytic conversion of CO to hydrocarbons on the surface of manganese-doped graphene oxide (Mn-doped GO), where the GO surface includes one OH group next to one Mn adatom. To gain insight into this process, we have employed calculations based on the density functional theory (DFT) to explore both the thermodynamic properties and reaction energy barriers. The Mn adatoms were found to significantly activate the catalyst surface by providing stronger adsorption geometries. Our study concentrated on two mechanisms for CO hydrogenation, resulting in either CH4 production via the reaction sequence CO → HCO → CH2O → CH2OH → CH2 → CH3 → CH4 or CH3OH formation through the CO → HCO → CH2O → CH2OH → CH3OH pathway. The results reveal that both products are likely to be formed on the Mn-doped GO surface on both thermodynamic grounds and considering the reaction energy barriers. Furthermore, the activation energies associated with each stage of the synthesis show that the conversion reactions of CH2 + OH → CH3 + O and CH2O + OH → CH2OH + O with energy barriers of 0.36 and 3.86 eV are the fastest and slowest reactions, respectively. The results also indicate that the reactions: CH2OH + OH → CH2 + O + H2O and CH2OH + OH → CH3OH + O are the most exothermic and endothermic reactions with reaction energies of −0.18 and 1.21 eV, respectively, in the catalytic pathways.

ORR properties of PtM (M = Fe and Ni) ordered alloys with the effect of small molecules of cyanamide

Ordered Pt alloy electrocatalysts have a special geometric structure and exhibit excellent oxygen reduction reaction (ORR) catalytic performance. Herein, we successfully prepared PtFe/PtNi ordered alloy catalysts by thermal annealing method under the protection of the encapsulated shell formed by pyrolysis of cyanamide molecules as well as the effect of the N element entering into the alloy system to cause defects, and kept the average particle size below 4 nm. The ordered structure enhances the electronic interactions, keeps more Pt0 valence states present and improves the ORR catalytic activity. Under acidic conditions, the PtFe ordered alloy catalyst had a mass activity of 0.752 A mgPt−1 and a specific activity of 1.138 mA cmPt−2, both of which were superior to the commercial Pt/C and disordered PtFe alloy. Importantly, the strong interaction between ordered Pt and Fe prevents the leaching of Fe and maintains high mass activity after a long period of circulation. DFT calculations show that the ordered PtFe alloy has a low reaction energy barrier, which is favorable for ORR.

Theoretical calculations and experimental verification of carbon dioxide reduction electrocatalyzed by metalloporphyrin

Metal-functionalized porphyrin-like graphene structures are promising electrocatalysts for carbon dioxide reduction reaction (CO2RR) as their metal centers can modulate activity. Yet, the role of metal center of metalloporphyrins (MTPPs) in CO2 reaction activity is still lacking deep understanding. Here, CO2RR mechanism on MTPPs with five different metal centers (M = Fe, Co, Cu, Zn and Ni) are examined by first-principles calculations. The *COOH formation is the rate determined step on the five MTPP structures, and the CoTPP exhibits the best CO2RR activity while ZnTPP and NiTPP are the worst, which is also verified by our experiment. The CO2RR activity is controlled by adsorption states of intermediates (*CO, *COOH), i.e., chemisorption (e.g., on CoTPP) and physisorption (on ZnTPP and NiTPP) of intermediates will lead to good and poor activity, respectively. The deeper the d-band center of the porphyrin ring complexed metal atom, the weaker bonding of MTPP with CO and COOH. Theoretical calculations and experimental results indicate that MTPPs with Co and Fe centers lead to a reduction in the energy barriers for the two uphill reaction steps in the electrocatalytic CO2 reduction process, thereby enhancing CO2 reduction electrocatalytic activity. Faradaic efficiency of CO is correlated with the reaction energy barrier of the first proton-coupled electron reduction process, displaying a strong linear correlation. This work provides a fundamental understanding of MTPPs used as electrocatalysts for CO2RR.

Synthesis of Double Trivalent Perovskite Quantum Dots Cs3BiSbX9 (X=Cl, Br, I) for Efficient CO2 Photoreduction Performance.

Non-toxic Bi halides have great potential in the field of CO2 photoreduction, but strong charge localization limits their charge separation and transfer. In this study, a series of Cs3BiSbX9 (X=Cl, Br, I) perovskite quantum dots (PQDs) are synthesized by antisolvent recrystallization at room temperature, in which Cs3BiSbBr9 PQDs has high selectivity (94.51%) and yield (15.32µmolg-1h-1) of CO2 to CO. In situ DRIFTS and theoretical calculations suggest that the surface charge can be tailored by halogen modulation, allowing for the customization of intermediate species. The Bi─Br─Sb symmetric charge distribution induced by the halogen Br promotes the formation of b─HCOO and reduces the reaction energy barrier of the rate-limiting step, while the weak electronegativity of Cl and the high electronegativity of I leads to m─HCOO and ─COOH production, which are detrimental to CO generation. This work provides new insights into the design of halide alloy perovskites for CO2 photoreduction.

Robust and efficient Iron-Based electrodes for hydrogen production from seawater at high current density above 1000 mA cm−2

The implementation of cheap iron-based catalysts for seawater electrolysis at high- current–density offers an economical and sustainable solution for industrial hydrogen production in near future. However, Fe-based electrodes suffer from poor intrinsic activity and corrosion resistance in seawater, resulting in unsatisfactory seawater splitting performance. Here, we reported the scale-up fabrication of whole-Fe-based electrodes (NiFe-X (X = O, P) NAs/Fe foam) by facile soaking-phosphating. Surface active layers exhibit enhanced corrosion resistance compared to bare Fe foam, and trace Ni modification lowers reaction energy barriers of cathodic NiFeP and in-situ generated anodic NiFeOOH, respectively. Thus, NiFe-P||NiFe-O pair only requires 1.93 V to deliver 3000 mA cm−2 at 6 M KOH, 60 °C for overall seawater splitting, and works stably for 200 h at 1000 mA cm−2. Furthermore, NiFe-X (X = O, P) NAs/Fe foam show impressive adaptation to fresh water/tap water/seawater and all kinds of renewable energies, presenting excellent flexibility for various environmental applications and scenarios.

Ultrafast In-Situ synthesis of flexible MoO3 anode in five seconds for High-Performance aqueous zinc ion hybrid capacitor

The efficient synthesis of high-performance α-MoO3 on flexible conductive substrates is crucial for enhancing its value in the field of energy storage. However, traditional synthesis methods currently employed often suffer from slow heating rates, intricate reaction processes involving multiple steps, sluggish reaction kinetics, high energy consumption, and prolonged preparation times, thereby hindering efficient production. Presented herein is a facile, ultrafast, and versatile approach utilizing microwave carbon thermal shock, a one-step reaction synthesis of α-MoO3 on carbon substrates within 5 s. During microwave carbon thermal shock, the precursor salt experiences an extremely rapid heating rate, swiftly decomposing to form small-sized α-MoO3 crystals. Simultaneously, this process promotes the oxidation of adjacent carbon sites, thereby imparting multi-scale defects and oxygen-containing functional groups to the resulting carbon cloth (CC). The exceptionally low reaction energy barriers and superior Gibbs free energy (ΔG) further substantiate the advantages of the microwave carbon thermal shock strategy over traditional synthesis methods in terms of both kinetics and thermodynamics. The air-assisted transient microwave carbonthermal shock (AMCTS) process circumvents high energy requirements, multistep reactions, and extended preparation times, endowing AMCTS-CC@MoO3 with remarkable flexibility and processability. In demonstrating its practical utility within zinc-ion hybrid micro capacitors, it exhibits outstanding specific capacitance (up to 2300mF cm−2) and mechanical stability. This air-assisted transient microwave thermal shock process provides an efficient route for ultrafast and low-cost synthesis of flexible zinc-ion anode materials.

Light-assisted ethanol dry reforming over NiZnOx hollow microspheres with enhanced activity and stability

Light-assisted thermocatalytic dry reforming of ethanol (EDR) utilizing the synergistic effect of photocatalysis and thermocatalysis is regarded as a promising route to convert greenhouse gas CO2 into value-added chemicals. In this work, double-shell NiZnOx hollow microspheres (NiZnOx-M) were synthesized as light-harvesting catalyst to enhance EDR performance under mild conditions. The characterization results of UV–vis–NIR and Photoluminescence Spectroscopy (PL) indicated that the band gap energy of NiZnOx-M catalyst was narrower because of the smaller Ni nanoparticles, thereby broadening its optical response range especially in visible light. The strong absorbance of light could greatly improve the activation of ethanol/CO2 and the gasification of carbon. With light irradiation, light could induce the transfer of photogenerated electron from semiconductor ZnO to active metal Ni, reducing the reaction energy barrier. Hence, NiZnOx-M catalyst showed superior photothermal catalytic activity along with good resistance capacity to coke accumulation and aggregation of active metal. Ethanol conversion was ca.2 times those obtained over NiZnOx-C prepared by conventional precipitation method. No obvious deactivation occurred after 100 h tests. This work provides some guidance for the design of high-performance photothermal catalyst to achieve the photo-thermal-chemical conversion of the greenhouse gases.

Facet and dual vacancy engineering-boosting BiOBr for enhanced CO2 and epoxide cycloaddition reaction under mild and cocatalyst-free conditions: Double substrate active sites and activated surface bromine ions synergy

Among the many strategies for CO2 resource utilization, the synthetic technology of cyclic carbonates with 100 % atom economy through CO2and epoxide is one of the most industrially viable routes, but its efficiency has been severely hampered by the lack of highly active catalytic sites. Moreover, due to the intrinsic thermodynamic stability and kinetic inertia of CO2 and the higher energy barrier of the ring-opening reaction of epoxides, the heterogeneous catalytic conversion of CO2 highly depends on harsh operating conditions, high temperatures and pressures, and the incorporation of cocatalysts. The development of efficient heterogeneous catalysts for CO2 conversion under cocatalyst-free and mild conditions has always been a challenge. Herein, we have proposed a synergetic strategy of facet and vacancy engineering for the construction of highly efficient heterogeneous catalyst BiO1-xBr1-y-(010) for CO2 cycloaddition, where introducing the OVs-BrVs pairs into typical (010) facets BiOBr with simultaneous surface Lewis acid sites Bi3+ and nucleophilic sites Br−. By combining theoretical calculations and a series of systematic experiments, such as CO2 temperature-programmed desorption, electron paramagnetic resonance and fluorescence probe analysis experiments, the introduced OVs-BrVs pair can not only form Bi3+-Bi(3-x)+ dual active sites on the surface, which activate PO and CO2 respectively to reduce the energy barrier of CO2 insertion, but also activate Br− near BrVs to enhance their nucleophilic attacking ability and reduce the energy barrier of epoxides ring-opening. As a result, the BiO1-xBr1-y-(010) with abundant surface OVs-BrVs pairs showed a high cyclic carbonates conversion of 99 % with 100 % selectivity under cocatalyst-free and mild conditions, far surpassing most heterogeneous catalytic systems. This work provides a completely new strategy to construct high-performance heterogeneous CO2 cycloaddition catalysts through a simple facet and vacancy engineering strategy to overcome the harsh operating conditions limitation and the use of cocatalysts.

Catalytic hydrogenation of CO2 to DME on surface Cu via highly efficient electron redistribution at the Cu0/Cu+ interface

The activity of copper-based bifunctional catalysts for CO2 hydrogenation to dimethyl ether (DME) is generally constrained by the loss of Cu0 sites during the reaction. Previous studies have focused on introducing additional elements to improve the stability of active sites. In this study, an electron redistribution of the Cu/Cu2O interface was constructed. Surface Cu0 provides active sites for H2 adsorption and dissociation, and the Cu0/Cu+ interface sites are more beneficial for the activation and hydrogenation of CO2. The Ointer–H moieties that form at interface sites reduce the reaction energy barrier of CH3OH synthesis, and the decomposition of H2COOH* to CH2O* species is the rate-limiting step. In addition, the Cu0/Cu+ interface restricts the migration of copper species and protects the weak acid sites of HZSM-5 during the reaction. The present work provides an atomic-level description of H2 dissociation and CO2 activation by Cu0/Cu+ surface and interface sites.

Elucidating reaction mechanisms in the oxidative depolymerization of sodium lignosulfonate for enhancing vanillin production: A Density Functional Theory study

Lignin is a vital organic constituent of plant biomass and it can be transformed into value-added chemicals through chemical processes. This study employs the Density Functional Theory (DFT) to investigate the mechanistic effects of various oxidants on the depolymerization of sodium lignosulfonate model compounds into vanillin. Under alkaline conditions, OH- ions participation in the hydrolysis of β-O-4 bonds has been predicted. The dehydration of dihydroconiferyl alcohol to form eugenol, with an energy barrier of 69.0 kcal/mol was identified as the major rate-determining step in the oxidation reaction. In the absence of an oxidant, the energy barrier for the oxidation of eugenol to vanillin was 77.8 kcal/mol. However, when using nitrobenzene or H2O2 as oxidants, the energy barrier has significantly decreased to 12.6 kcal/mol and 21.4 kcal/mol, respectively. The effects of temperature and pressure on the rate-determining step of the reaction were analyzed using Statistical Product and Service Solutions (SPSS) software. These results have demonstrated that the energy barrier for the hydrolysis reaction's rate-determining step is positively correlated with temperature but negatively correlated with pressure. These theoretical findings would potentially help in designing the experiments and aid in enhancing the selectivity and yield of vanillin.

The regulation mechanism of transition metal doping on Hg0 adsorption and oxidation on Ce/TiO2(001) surface: A DFT study

The mercury oxidation performance of Ce/TiO2 catalyst can be further enhanced by transition metal modifications. This study employed density functional theory (DFT) calculations to investigate the adsorption and oxidation mechanisms of Hg0 on Ce/TiO2(001) and its transition metal modified surfaces. According to the calculation results, Ru-, Mo-, Nb-, and Mn-doping increased the affinity of the Ce/TiO2(001) surface towards Hg0 and HCl, thereby facilitating the efficient capture and oxidation of Hg0. The increased adsorption energy (Eads) of the intermediate HgCl on the modified surfaces could promote its conversion to the final product HgCl2. The modification of transition metals impeded the desorption of the final products HgCl2 and HgO, but it did not serve as the rate-determining step. The oxidation of Hg0 by lattice oxygen and HCl followed the Mars-Maessen and Langmuir-Hinshelwood mechanisms, respectively. HCl exhibited higher mercury oxidation ability than lattice oxygen. The reactivity of lattice oxygen could be further improved by doping transition metals, their promotion order was Ru > Nb > Mo > Mn. In a HCl atmosphere, Mn modification could significantly reduce the energy barrier for HCl activation and HgCl2 formation, providing the optimal enhancement for the mercury oxidation ability of Ce/TiO2 catalyst. The screening method of transition metal modified components based on surface adsorption reaction and oxidation energy barrier was proposed in this study, which provided theoretical guidance for the development of CeTi based catalysts with high mercury oxidation activity.