Reaction Pathways Research Articles

Visualizing Electrochemical CO2 Conversion via the Emerging Scanning Electrochemical Microscope: Fundamentals, Applications and Perspectives.

With the rapid development and maturity of electrochemical CO2 conversion involving cathodic CO2 reduction reaction (CO2RR) and anodic oxygen evolution reaction (OER), conventional ex situ characterizations gradually fall behind in detecting real-time products distribution, tracking intermediates, and monitoring structural evolution, etc. Nevertheless, advanced in situ techniques, with intriguing merits like good reproducibility, facile operability, high sensitivity, and short response time, can realize in situ detection and recording of dynamic data, and observe materials structural evolution in real time. As an emerging visual technique, scanning electrochemical microscope (SECM) presents local electrochemical signals on various materials surface through capturing micro-current caused by reactants oxidation and reduction. Importantly, SECM holds particular potentials in visualizing reactive intermediates at active sites and obtaining instantaneous morphology evolution images to reveal the intrinsic reactivity of active sites. Therefore, this review focuses on SECM fundamentals and its specific applications toward CO2RR and OER, mainly including electrochemical behavior observation on local regions of various materials, target products and onset potentials identification in real-time, reaction pathways clarification, reaction kinetics exploration under steady-state conditions, electroactive materials screening and multi-techniques coupling for a joint utilization. This review undoubtedly provides a leading guidance to extend various SECM applications to other energy-related fields.

Shifting the Oxygen-Evolution Reaction Pathway via Cation Engineering to Activate Lattice Oxygen in Metal-Organic Frameworks.

Metal-organic frameworks (MOFs) as promising electrocatalysts have been widely studied, but their performance is limited by conductivity and coordinating saturation. This study proposes a cationic (V) modification strategy and evaluates its effect on the electrocatalytic performance of CoFe-MOF nanosheet arrays. The optimal V-CoFe-MOF/NF electrocatalyst exhibits excellent oxygen-evolution reaction (OER)/hydrogen-evolution reaction (HER) performance (231 mV at 100 mA cm-2/86 mV at 10 mA cm-2) in alkaline conditions, with its OER durability exceeding 400 h without evident degradation. Furthermore, as a bifunctional electrocatalyst for water splitting, a small cell voltage is achieved (1.60 V at 10 mA cm-2). The practicability of the catalyst is further evaluated by membrane electrode assembly (MEA), showing outstanding activity (1.53 V at 10 mA cm-2) and long-term stability (at 300 mA cm-2). Moreover, our results reveal the apparent reconstruction properties of V-CoFe-MOF/NF in alkaline electrolytes, where the partially dissolved V promotes the formation of more active β-MOOH. The mechanism study shows the OER mechanism shifts to a lattice oxygen oxidation mechanism (LOM) after V doping, which directly avoids complex multistep adsorption mechanism and reduces reaction energy. This study provides a cation mediated strategy for designing efficient electrocatalysts.

A highly efficient clean hydrometallurgy process for gold leaching in a Fenton oxidation assisted thiourea system

Clean hydrometallurgy processes, formed by “oxidant-ligand” systems, present promising strategies for gold leaching to mitigate the environmental impact of cyanidation. In this work, a Fenton oxidation-assisted thiourea system was proposed, employing reactive oxygen species (ROS, generated from Fenton reaction) as oxidant and thiourea as the ligand, respectively. By precise parameters control, 100% leaching of gold was rapidly achieved within 30 min from a roasted gold concentrate, highlighting extremely fast kinetics. Furthermore, this system was optimized by incorporating nitrilotriacetic acid (NTA) as an additive, which significantly reduced the thiourea consumption and produced the same gold leaching (100%, 60 min). Experimental results demonstrate that NTA lowers the solution potential (ORP) and eliminates the side reactions between iron ions and thiourea, thereby reducing thiourea decomposition. Surprisingly, the combination of Fenton oxidation and thiourea showed a high selectivity of the generation of ROS, with superoxide radical anion (•O2−) dominating, singlet oxygen (1O2) co-existing, but hydroxyl radical (•OH) absenting. Importantly, the moderate •O2− primarily contributes to gold leaching, which is generated through a chain reaction pathway between iron complex and H2O2 (Fe3+-Ligand+H2O2 → Ligand-Fe3+-OOH → Fe2+-Ligand+•O2−). Besides, the generation process of •O2− can be regulated by adding NTA. This work presented a prospective way in establishing the clean hydrometallurgy processes for efficient gold leaching.

Gas-Phase Preparation of the 14π Hückel Polycyclic Aromatic Anthracene and Phenanthrene Isomers (C14H10) via the Propargyl Addition-BenzAnnulation (PABA) Mechanism.

Polycyclic aromatic hydrocarbons (PAHs) imply the missing link between resonantly stabilized free radicals and carbonaceous nanoparticles, commonly referred to as soot particles in combustion systems and interstellar grains in deep space. Whereas gas phase formation pathways to the simplest PAH - naphthalene (C10H8) - are beginning to emerge, reaction pathways leading to the synthesis of the 14π Hückel aromatic PAHs anthracene and phenanthrene (C14H10) are still incomplete. Here, by utilizing a chemical microreactor in conjunction with vacuum ultraviolet (VUV) photoionization (PI) of the products followed by detection of the ions in a reflectron time-of-flight mass spectrometer (ReTOF-MS), the reaction between the 1'- and 2'-methylnaphthyl radicals (C11H9⋅) with the propargyl radical (C3H3⋅) accesses anthracene (C14H10) and phenanthrene (C14H10) via the Propargyl Addition-BenzAnnulation (PABA) mechanism in conjunction with a hydrogen assisted isomerization. The preferential formation of the thermodynamically less stable anthracene isomer compared to phenanthrene suggests a kinetic, rather than a thermodynamics control of the reaction.

Fostering a Holistic Understanding of the Full Volatility Spectrum of Organic Compounds from Benzene Series Precursors through Mechanistic Modeling.

A comprehensive understanding of the full volatility spectrum of organic oxidation products from the benzene series precursors is important to quantify the air quality and climate effects of secondary organic aerosol (SOA) and new particle formation (NPF). However, current models fail to capture the full volatility spectrum due to the absence of important reaction pathways. Here, we develop a novel unified model framework, the integrated two-dimensional volatility basis set (I2D-VBS), to simulate the full volatility spectrum of products from benzene series precursors by simultaneously representing first-generational oxidation, multigenerational aging, autoxidation, dimerization, nitrate formation, etc. The model successfully reproduces the volatility and O/C distributions of oxygenated organic molecules (OOMs) as well as the concentrations and the O/C of SOA over wide-ranging experimental conditions. In typical urban environments, autoxidation and multigenerational oxidation are the two main pathways for the formation of OOMs and SOA with similar contributions, but autoxidation contributes more to low-volatility products. NOx can reduce about two-thirds of OOMs and SOA, and most of the extremely low-volatility products compared to clean conditions, by suppressing dimerization and autoxidation. The I2D-VBS facilitates a holistic understanding of full volatility product formation, which helps fill the large gap in the predictions of organic NPF, particle growth, and SOA formation.

Cobalt‐Catalyzed Wacker‐Type Aerobic Oxidation of Olefins into Ketones Enabled by PMHS: Giving Value to a Chemical Waste with Optimal Atom‐Economy

AbstractHerein, it is demonstrated that a chemical waste from the silicon industry, namely polymethylhydrosiloxane (PMHS), is a suitable hydrosilane source for the challenging, selective aerobic oxidation of olefins into methyl ketones under cobalt catalysis: a first row, abundant in the Earth's crust and cheap metal with low toxicity. The catalytic system operates under unprecedented, stoichiometric amounts of hydrosilane while the cobalt catalyst loading is kept at a very low 1 mol% with the reactions being finished in less than 1 hour with very high turnover numbers (1,340) and record‐breaking turnover frequency values up to 530 h−1. Mechanistic studies highlight the key role of the porphyrin ligand for stabilizing the active cobalt species that does follow a radical‐based reaction pathway under these particular conditions. These results are relevant for replacing the expensive and scarce palladium catalyst, traditionally used for Wacker‐type oxidations, by first‐row, Earth‐abundant transition metals under green conditions including the efficient valorization of a chemical waste such as PMHS.

Dual-comb spectroscopy of ammonia formation in non-thermal plasmas

Plasma-activated chemical transformations promise the efficient synthesis of salient chemical products. However, the reaction pathways that lead to desirable products are often unknown, and key quantum-state-resolved information regarding the involved molecular species is lacking. Here we use quantum cascade laser dual-comb spectroscopy (QCL-DCS) to probe plasma-activated NH3 generation with rotational and vibrational state resolution, quantifying state-specific number densities via broadband spectral analysis. The measurements reveal unique translational, rotational and vibrational temperatures for NH3 products, indicative of a highly reactive, non-thermal environment. Ultimately, we postulate on the energy transfer mechanisms that explain trends in temperatures and number densities observed for NH3 generated in low-pressure nitrogen-hydrogen (N2–H2) plasmas.

Copper-Catalyzed [3 + 2] Annulation of O-Acyl Oximes with 4-Sulfonamidophenols for the Synthesis of 5-Sulfonamidoindoles and 2-Amido-5-sulfonamidobenzofuran-3(2H)-ones.

A copper-catalyzed [3 + 2] annulation of O-acyl oximes with 4-sulfonamidophenols is developed. The advantage of this method lies in the concurrent double activation of two substrates to form nucleophilic enamines and electrophilic quinone monoimines. The substituent on the α-carbon of O-acyl oxime determines two different reaction pathways, thereby leading to the selective generation of 5-sulfonamidoindoles and 2-amido-5-sulfonamidobenzofuran-3(2H)-ones.

Competing Reaction Mechanisms of Peptide Bond Formation in Water Revealed by Deep Potential Molecular Dynamics and Path Sampling.

The formation of an amide bond is an essential step in the synthesis of materials and drugs, and in the assembly of amino acids to form peptides. The mechanism of this reaction has been studied extensively, in particular to understand how it can be catalyzed, but a representation capable of explaining all the experimental data is still lacking. Numerical simulation should provide the necessary molecular description, but the solvent involvement poses a number of challenges. Here, we combine the efficiency and accuracy of neural network potential-based reactive molecular dynamics with the extensive and unbiased exploration of reaction pathways provided by transition path sampling. Using microsecond-scale simulations at the density functional theory level, we show that this method reveals the presence of two competing distinct mechanisms for peptide bond formation between alanine esters in aqueous solution. We describe how both reaction pathways, via a general base catalysis mechanism and via direct cleavage of the tetrahedral intermediate respectively, change with pH. This result contrasts with the conventional mechanism involving a single pathway in which only the barrier heights are affected by pH. We show that this new proposal involving two competing mechanisms is consistent with the experimental data, and we discuss the implications for peptide bond formation under prebiotic conditions and in the ribosome. Our work shows that integrating deep potential molecular dynamics with path sampling provides a powerful approach for exploring complex chemical mechanisms.

Experimental and Computational Study of Pyrogenic Carbonaceous Matter Facilitated Hydrolysis of 2,4-Dinitroanisole (DNAN).

This study investigated the reaction pathway of 2,4-dinitroanisole (DNAN) on the pyrogenic carbonaceous matter (PCM) to assess the scope and mechanism of PCM-facilitated surface hydrolysis. DNAN degradation was observed at pH 11.5 and 25 °C with a model PCM, graphite, whereas no significant decay occurred without graphite. Experiments were performed at pH 11.5 due to the lack of DNAN decay at pH below 11.0, which was consistent with previous studies. Graphite exhibited a 1.78-fold enhancement toward DNAN decay at 65 °C and pH 11.5 relative to homogeneous solution by lowering the activation energy for DNAN hydrolysis by 54.3 ± 3.9%. This is supported by our results from the computational modeling using Car-Parrinello simulations by ab initio molecular dynamics/molecular mechanics (AIMD/MM) and DFT free energy simulations, which suggest that PCM effectively lowered the reaction barriers by approximately 8 kcal mol-1 compared to a homogeneous solution. Quaternary ammonium (QA)-modified activated carbon performed the best among several PCMs by reducing DNAN half-life from 185 to 2.5 days at pH 11.5 and 25 °C while maintaining its reactivity over 10 consecutive additions of DNAN. We propose that PCM can affect the thermodynamics and kinetics of hydrolysis reactions by confining the reaction species near PCM surfaces, thus making them less accessible to solvent molecules and creating an environment with a weaker dielectric constant that favors nucleophilic substitution reactions. Nitrite formation during DNAN decay confirmed a denitration pathway, whereas demethylation, the preferred pathway in homogeneous solution, produces 2,4-dinitrophenol (DNP). Denitration catalyzed by PCM is advantageous to demethylation because nitrite is less toxic than DNAN and DNP. These findings provide critical insights for reactive adsorbent design that has broad implications for catalyst design and pollutant abatement.

Spin-Restricted Descriptions of Singlet Oxygen Reactions from XMS-CASPT2 Benchmarks.

Reactions of singlet oxygen are numerous, some of which are desired but many are unwanted. Therefore, the ability to correctly predict and interpret this reactivity for complex molecular systems is essential to our understanding of singlet oxygen reactions. DFT is widely used for predicting many reactions but is not suited to degenerate electronic structures; application to isolated singlet oxygen often uses the spin-unrestricted formalism, which results in severe spin contamination. In this work, we demonstrate that spin-restricted DFT can correctly describe the reaction pathway for four prototypical singlet oxygen reactions. By careful benchmarking with XMS-CASPT2, we show that, from the first transition state onward, the degeneracy of the 1Δg state is broken due to differing interactions of the (degenerate) π* orbitals with the organic substrate; this result is well replicated with DFT. These findings demonstrate the utility of using spin-restricted DFT to explore reactions, opening the way to confidently use this computationally efficient method for molecular systems of medium to large organic molecules.

Protonation of an Imine-linked Covalent Organic Framework for Efficient H2O2 Photosynthesis under Visible Light up to 700 nm.

Covalent organic frameworks (COFs) are promising photocatalysts for H2O2 production from water via oxygen reduction reactions (ORR). The design of COFs for efficient H2O2 production indubitably hinges on an in-depth understanding of their ORR mechanisms. In this work, taking an imine-linked COF as an example, we demonstrate that protonation of the functional units such as imine, amine, and triazine, is a highly efficient strategy to upgrade the activity levels for H2O2 synthesis. The protonation not only extends the light absorption of the COF but also provides proton sources that directly participate in H2O2 generation. Notably, the protonation simplifies the reaction pathways of ORR to H2O2, i.e. from an indirect superoxide radical ([[EQUATION]]) mediated route to a direct one-step two-electron route. Theoretical calculations confirm that the protonation favors H2O2 synthesis due to easy access of protons near the reaction sites that removes the energy barrier for generating *OOH intermediate. These findings not only extend the mechanistic insight into H2O2 photosynthesis but also provide a rational guideline for the design and upgradation of efficient COFs.

Protonation of an Imine‐linked Covalent Organic Framework for Efficient H2O2 Photosynthesis under Visible Light up to 700 nm

Covalent organic frameworks (COFs) are promising photocatalysts for H2O2 production from water via oxygen reduction reactions (ORR). The design of COFs for efficient H2O2 production indubitably hinges on an in‐depth understanding of their ORR mechanisms. In this work, taking an imine‐linked COF as an example, we demonstrate that protonation of the functional units such as imine, amine, and triazine, is a highly efficient strategy to upgrade the activity levels for H2O2 synthesis. The protonation not only extends the light absorption of the COF but also provides proton sources that directly participate in H2O2 generation. Notably, the protonation simplifies the reaction pathways of ORR to H2O2, i.e. from an indirect superoxide radical ([[EQUATION]]) mediated route to a direct one‐step two‐electron route. Theoretical calculations confirm that the protonation favors H2O2 synthesis due to easy access of protons near the reaction sites that removes the energy barrier for generating *OOH intermediate. These findings not only extend the mechanistic insight into H2O2 photosynthesis but also provide a rational guideline for the design and upgradation of efficient COFs.

Cyclization Reactions of 1,5-Diynes: Mechanisms and the Role of the Central Linker.

This study employed computational methods to elucidate the influence of structural features on the cyclization pathways of 1,5-diynes through the 5-endo-dig and 6-endo-dig mechanisms. The results revealed that the nature of the central linker played a significant role in dictating the preferred cyclization pathway. Notably, the capacity of this linker to extend delocalization appears to be the key factor governing the reaction pathway preference.

Thermodiffusively unstable laminar hydrogen flame in a sufficiently large 3D computational domain – Part II: NOx formation mechanism and flamelet modeling

In this work, the NOx formation mechanism in three-dimensional (3D) thermodiffusively unstable premixed hydrogen flames is investigated through direct numerical simulations (DNS) and a reaction path analysis based on the DNS dataset. In part I of this study (Wen et al., 2024), the characteristic patterns of the instabilities were studied using the same dataset. Here, first, the effects of the computational setup (2D vs. 3D) and curvature on the flux ratio of nitrogen atom are quantified. In addition, the composition space model (CSM) proposed in previous works is extended to account for the NOx chemical reaction mechanism to predict NOx formation in thermodiffusively unstable premixed hydrogen flames. The flamelet solutions are obtained from the premixed flamelet equations in composition space so that the wide range of curvatures associated with the strongly corrugated flame front can be considered. The performance of the CSM in predicting the NOx species and the important radicals involved in the NOx formation pathways is evaluated through an a priori analysis. To investigate the effects of curvature on the NOx formation pathways and the performance of the composition space model, the positively- and negatively-curved regions in the DNS are studied separately. The results show that different from the 2D simulation, the NNH reaction pathway becomes dominant in the 3D simulation due to the increased range of curvature, which promotes the accumulation of the highly diffusive H radical in the positively-curved regions. The NNH reaction pathway is dominant in the positively-curved regions, while the N2O reaction pathway is more important in the negatively-curved regions. The flamelet model based on the composition space solutions that consider the effects of curvature yields accurate predictions for the radicals that are sensitive to the effects of curvature.Novelty and significance statementThe novelty of the present work includes the following aspects,(i) Analysis of NOx formation mechanism based on the large-scale 3D DNS dataset of a laminar fuel-lean premixed hydrogen flame on a sufficiently large domain;(ii) Quantification of the effects of computational setup (2D and 3D) and curvature on the NOx formation pathways;(iii) Extension of the previous composition space model (CSM) by incorporating the NOx chemical reaction mechanism to consider the effects of curvature on the NOx formation.

Towards understanding the role of acidity on levulinic acid conversion using alumina-niobia mixed oxide-supported catalysts

The catalytic transformation of levulinic acid (LA) represents a pivotal advancement towards establishing a sustainable biorefinery industry. Hence, this study investigated the intricate role of the catalyst acidity, which remains relatively unexplored, in the catalytic transformation of LA. A range of alumina-niobia supported nickel-copper catalysts, with varying alumina (Al) to niobia (Nb) ratios, was synthesized and characterized. The results of characterization techniques revealed that the strength, quantity, and nature of the acidic sites of the catalysts were modified by the variations in the Al to Nb ratios. Further, a correlation between the acidic properties of the catalysts and the result of the reaction runs and poisoning experiments was established. Specifically, Lewis acid sites were responsible for the conversion of LA into angelica lactone (AL), which can be subsequently hydrogenated to gamma-valerolactone (GVL). Conversely, Brønsted acid sites are required for the ring-opening reactions of GVL which led to the formation of 2-methyltetrahydrofuran (MTHF) and valeric acid (VA). Notably, selectivities as high as 85.0% for MTHF and 67.0 % for VA were achieved with Ni-Cu/Al-Nb (6) and Ni-Cu/Nb2O5, respectively. To the best of our knowledge, this represents the highest MTHF selectivity in solvent-free catalytic conversion of LA. Additionally, based on our findings, we propose a comprehensive reaction pathway employing alumina-niobia-supported nickel-copper catalysts, shedding light on the intricate interplay of acidity in the LA conversion process. This study not only deepens our understanding of LA transformation but also holds great promise for optimizing catalytic processes in pursuit of sustainable and eco-friendly biorefinery technologies.

Termolecular Eley–Rideal pathway for catalytic oxidation of nitric oxide on [Pt2]0,± dimers using O2

AbstractA comprehensive density functional theory (DFT) investigation of the catalytic oxidation of NO to NO2 on neutral and charged [Pt2]0,± dimers has been considered employing M06L/def2TZVP level of theory. Single as well as co‐adsorption energies of NO and O2 molecules suggest that the traditional Langmuir Hinshelwood (LH) mechanism and less explored termolecular Eley–Rideal (TER) and termolecular Langmuir Hinshelwood (TLH) mechanisms, are suitable for a full catalytic reaction pathway in which two NO molecules are converted to two NO2 molecules, initiated by an activated O2 molecule. Activation barrier reveals that the TER mechanism is found to be more reliable in converting two NO molecules into two NO2 molecules on [Pt2]¯ dimer. In addition to shedding light on the intrinsic characteristics of Pt2 dimers, the study will serve as a benchmark for investigating the oxidation process of NO to NO2 utilizing models of termolecular chemical processes.

Flame characteristics and NO emission behaviors of methane/ammonia counterflow premixed flames with opposed N2 or air stream

Behaviors of methane/ammonia counterflow premixed flames and NO emission are numerically and experimentally investigated with opposed N2 or air stream by varying strain rate (ag) and equivalence ratio (ϕ). The premixed stream is 80% methane and 20% ammonia by volume mixed with air considering the utilization of ammonia by blending hydrocarbon fuels. The opposed stream is either N2 or air considering the potential application in gas turbines having single- or two-stage combustion. The simulations are conducted by increasing ag up to flame extinction for a specified ϕ and an experiment is conducted to evaluate various kinetic mechanisms. The extinction strain rate increases monotonically with ϕ with opposed air stream (AS), while increases and then decreases with opposed nitrogen stream (NS). The extinction mechanisms are explained by adopting the concepts of the local equilibrium temperature and heat loss ratio. For lean and rich mixtures with NS and lean mixtures with AS, the extinction occurs due to comparable effects of incomplete reaction and heat loss from the flame to the downstream burnt region. While for rich mixtures with AS, the extinction is attributed mainly to incomplete reaction. The contribution of thermal NO as compared with prompt NO in NO production is weak for all cases with NS and AS. The emission index (EINO) for lean and rich mixtures with NS and for lean mixtures with AS decreases monotonically with the increase of strain rate for all ϕ. Increasing equivalence ratio at a specified ag decreases NO production for lean and rich mixtures with NS and lean mixtures with AS. While for rich mixtures with AS, the EINO increases monotonically with ag. From the reaction pathway analysis, for lean mixtures, the effect of increasing ag on the reduction of NO production is attributed by weakening NH-related reaction paths, while NH2-related reaction paths change little. When ϕ increases for a specified ag with NS, NO production is reduced by weakening NH2-related reaction paths and strengthening NH-related reaction paths. For rich mixtures with AS, increasing ag increases NO production by strengthening NH2-related reaction paths.

Operando investigation of catalytic trichloroethylene combustion over metal-doped CeO2 nanorods

The remediation of chlorinated volatile organic compounds is an intractable issue for it typically requires high temperatures and generates undesirable byproducts. This work utilized a series of representative transition metals (i.e., Cr, Cu, V) to modify the morphology, surface oxygen, and acidity of the CeO2 nanorods for trichloroethylene (TCE) treatment. A spectroscopic operando DRIFT − online GCMS reactor was introduced to examine the catalytic performance and elucidate the reaction pathway. Among them, Cr-CeO2 exhibited 50 % (T50) and 90 % (T90) TCE conversions with no byproduct at 171 °C and 241 °C, respectively. The performances of Cu-CeO2 (T90 = 391 °C), V-CeO2 (T90 = 423 °C) and CeO2 (T90 = 494 °C) were inferior to Cr-CeO2 (T90 = 241 °C), with obvious C2Cl4 generated in the TCE oxidation. It reveals that TCE adsorbed on Cr-CeO2 is dechlorinated on acidic sites and oxidized to carbonate/formate intermediates by the surface oxygen then facilely to generate carbon oxides, while TCE is adsorbed as chlorinated species (CH2ClCH2O−) on the other three catalysts which occupy the surface and require higher temperature to be oxidized. The abundant medium-strong acidic sites and surface oxygen species of Cr-CeO2 nanorods are responsible for the low-temperature activation via C-Cl cleavage on acidic sites and fast oxidation of hydrocarbon intermediates in the TCE oxidation, respectively.

Reaction mechanism and kinetics for Pt/C and Au/C catalyzed aqueous phase glycerol oxidation to various carboxylic acids

Fundamental understanding of heterogeneously catalytic aerobic oxidation of polyol is highly desirable for sustainable and efficient chemical synthesis. Herein, based on the purpose of exploring the selectivity of various carboxylic acids on Pt-Au catalysts with different ratios, we conducted a comprehensive investigation into the reaction pathways of glycerol oxidation over pristine Pt/C and Au/C catalysts via experiments, kinetics analysis and DFT calculations. Structural characterizations revealed that Pt/C exhibits a higher metallic state and more d electrons, thus tending to strongly adsorb OH– and promote oxygen activation. Conversely, the weak oxygen activation of Au/C could be attributed to fewer cationic high valence state and d electrons. Furthermore, the Langmuir-Hinshelwood kinetic model and DFT calculations indicate both catalysts exhibit obvious differences in product distribution. Specifically, Pt demonstrated higher selectivity towards lactic acid by facilitating dehydration of C-OH in glyceraldehyde and promoting timely desorption of lactic acid species. In contrast, Au displayed more glycolic acid products caused by strengthening oxidative cleavage of C-C bond in glyceric acid. Expanding to bimetallic catalysts, it was observed that catalysts with higher Au content exhibit enhanced selectivity towards the oxidation of glyceric acid to glycolic acid, while those with a higher Pt ratio demonstrate increased selectivity for the oxidation of glycerol to lactic acid. These findings provide valuable insights for guiding the design and optimization of this catalytic process to achieve targeted product generation.