Efficient Oxidation Research Articles

The mechanism and origins of the chemo- and regio-selectivity of ruthenium porphyrin catalyzed C[sbnd]H bonds oxidation

Selective functionalization of polymers derived from branched alkane monomers is extremely challenging due to the low reactivity of CH bonds and uncontrolled depolymerization. In this work, the chemoselective and regioselective catalytic oxygenation mechanism of hydrocarbons with ruthenium porphyrin complexes and aromatic N-oxides was investigated by density functional theory (DFT) calculations. The results revealed that the oxoruthenium porphyrin species with remarkable reactivity as oxygen transfer agents is responsible for the hydrogen abstraction from CH bonds followed by fast hydroxyl radical rebound. Details regarding the calculations of various oxidation processes show that the regioselectivity is related to the intrinsic strength of different CH bonds in branched alkanes and the charge transfer of the hydrogen atom transfer (HAT) step. Comparing the oxidations of branched alkanes to alcohols and ketones, the chemoselectivity is attributed to the relative barriers of HAT pathways in the two-step oxidation stage. Finally, the substituent effects of fluorine in the porphyrin ligand are elucidated and a stronger electron-withdrawing group is predicted to promote the HAT process and regulate hydroxyl radical rebound, ultimately enabling more efficient oxidation. These findings provide relevant information for understanding the selective oxidation of polyolefins through transition metal catalysis and enzymatic catalysis.

Density functional theory-based screening of Ti4C3O2-loaded single atoms for efficient selective catalytic oxidation of formaldehyde

Indoor formaldehyde (HCHO) pollution poses a major risk to human health. Low-temperature catalytic oxidation is an effective method for HCHO removal. The high activity and selectivity of single atomic catalysts provide a possibility for the development of efficient non-precious metal catalysts. In this study, the most stable single-atom catalyst Ti-Ti4C3O2 was screened by density functional theory among many single atomic catalysts with two-dimensional (2D) monolayer Ti4C3O2 as the support. The computational results show that Ti-Ti4C3O2 is highly selective to HCHO and O2 in complex environments. The HCHO oxidation reaction pathways are proposed based on the Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms. According to the reaction energy and energy span models, the E-R mechanism has a lower maximum energy barrier and higher catalytic efficiency than the L-H mechanism. In addition, the stability of the Ti-Ti4C3O2 structure and active center was verified by diffusion energy barrier and ab initio molecular dynamics simulations. The above results indicate that Ti-Ti4C3O2 is a promising non-precious metal catalyst. The present study provides detailed theoretical insights into the catalytic oxidation of HCHO by Ti-Ti4C3O2, as well as an idea for the development of efficient non-precious metal catalysts based on 2D materials.

Photorelease of Nitric Oxide (NO) in Mono- and Bimetallic Ruthenium Nitrosyl Complexes: A Photokinetic Investigation with a Two-Step Model.

Two monometallic and three bimetallic ruthenium acetonitrile (RuMeCN) complexes are presented and fully characterized. All of them are built from the same skeleton [FTRu(bpy)(MeCN)]2+, in which FT is a fluorenyl-substituted terpyridine ligand and bpy is the 2,2'-bipyridine. The crystal structure of [FTRu(bpy)(MeCN)](PF6)2 is presented. A careful spectroscopic analysis allows establishing that these 5 RuMeCN complexes can be identified as the product of the photoreaction of 5 related RuNO complexes, investigated as efficient nitric oxide (NO) donors. Based on this set of complexes, the mechanism of the NO photorelease of the bimetallic complexes has been established through a complete investigation under irradiations performed at 365, 400, 455, and 490 nm wavelength. A two-step (A → B → C) kinetic model specially designed for this purpose provides a good description of the mechanism, with quantum yields of photorelease in the range 0.001-0.029, depending on the irradiation wavelength. In the first step of release, the quantum yields (ϕAB) are always found to be larger than those of the second step (ϕBC), at any irradiation wavelengths.

The effects of inner electrode shape on the performance of dielectric barrier discharge reactor for oxidative removal of NO and SO2

Abstract Seagoing vessels are responsible for more than 90% of global freight traffic, but meanwhile, emission pollutants (NOx and SOx) of seagoing vessels also cause serious air pollution. Nonthermal plasma (NTP) combined with wet scrubbing technology is considered to be a promising technology. In order to improve the oxidation efficiency and energy efficiency of the NTP reactor, the screw and rod inner electrodes of dielectric barrier discharge (DBD) reactor were investigated. To analyze the mechanism, the optical emission spectra (OES) of NTP was measured and numerical calculation was applied. The experiment results show that the NO oxidation removal efficiency of screw electrode is lower than that of rod electrode. However, the SO2 removal efficiency of screw electrode is higher. According to the OES experiment and numerical calculation, the electric field intensity of the screw electrode surface is much higher than that of the rod electrode surface, and it is easier to generate N radicals to form NO. For the same energy density condition, the OH radical generation efficiency of the screw electrode reactor is similar to that of the rod electrode, but the gas temperature in the discharge gap is higher. Therefore, the SO2 oxidation efficiency of the thread electrode is higher. This study provides guidance for the optimization of oxidation efficiency and energy consumption of DBD reactor.

Tuning Surface Electronics State of P-Doped In2.77S4/In(OH)3 toward Efficient Photoelectrochemical Water Oxidation.

Indium sulfide with a two-dimensional layered structure offers a platform for catalyzing water oxidation by a photoelectrochemical process. However, the limited hole holders hinder the weak intrinsic catalytic activity. Here, the nonmetallic phosphorus atom is coordinated to In2.77S4/In(OH)3 through a bridge-bonded sulfur atom. By substituting the S position by the P dopant, the work function (surface potential) is regulated from 445 to 210 mV, and the lower surface potential is shown to be beneficial for holding the photogenerated holes. In2.77S4/In(OH)3/P introduces a built-in electric field under the difference of Fermi energy, and the direction is from the bulk to the surface. This band structure results in upward band bending at the interface of In2.77S4/In(OH)3 and P-doped sites, which is identified by density functional theory calculations (∼0.8 eV work function difference). In2.77S4/In(OH)3/P stands out with the highest oxidation efficiency (ηoxi = 70%) and charge separation efficiency (ηsep = 69%). Importantly, it delivers a remarkable water oxidation photocurrent density of 2.51 mA cm-2 under one sun of illumination.

A theoretical study on toluene oxidization by OH radical

Toluene, a prominent member of volatile organic compounds (VOCs), exerts a substantial adverse influence on both human life and the environment. In the context of advanced oxidation processes, the ·OH radical emerges as a highly efficient oxidant, pivotal in the elimination of VOCs. This study employs computational quantum chemistry methods (G4MP2//B3LYP/6-311++G(d,p)) to systematically investigate the degradation of toluene by ·OH radicals in an implicit solvent model, and validates the rationale of choosing a single-reference method using T1 diagnostics. Our results suggest three possible reaction mechanisms for the oxidation of toluene by ·OH: firstly, the phenyl ring undergoes a hydrogen abstraction reaction followed by direct combination with ·OH to form cresol; secondly, ·OH directly adds to the phenyl ring, leading to ring opening; thirdly, oxidation of sidechain to benzoic acid followed by further addition and ring opening. The last two oxidation pathways involve the ring opening of toluene via the addition of ·OH, significantly facilitating the process. Therefore, both pathways are considered feasible for the degradation of toluene. Subsequently, the UV-H2O2 system was designed to induce the formation of ·OH for toluene degradation and to identify the optimal reaction conditions. It was demonstrated that ·OH and 1O2 are the primary active species for degrading toluene, with their contribution ranking as ·OH > 1O2. The intermediates in the mixture solution after reactions were characterized using GC–MS, demonstrating the validity of theoretical predictions. A comparative study of the toluene consumption rate revealed an experimental comprehensive activation energy of 10.33 kJ/mol, which is consistent with the preliminary activation energies obtained via theoretical analysis of these three mechanisms (0.56 kJ/mol to 13.66 kJ/mol), indicating that this theoretical method can provide a theoretical basis for experimental studies on the oxidation of toluene by ·OH.

Improving Oxidative Catalytic Efficiency for Fuels Desulfurization Using Hybrid Materials Based in MOF‐808@SBA‐15

This work unveils a route for a new generation of heterogeneous polyoxometalate (POMs) based catalysts associated to the preparation of hybrid materials as a triad of POMs, mesoporous silica (SBA‐15) and microporous MOF structures (MOF‐808). The prepared catalyst, PMo12@MOF‐808@SBA‐15, with the main active center the phosphomolybdic acid (PMo12), was successfully applied for the desulfurization of a multicomponent fuel. Its oxidative catalytic performance showed to be considerable superior to the isolated POM@MOF and able to be recycled for more catalytic cycles without active loss. The higher catalytic performance seems to be directly related with the preparation of a more amorphous MOF structure within the channels of SBA‐15, in the presence of active POM guests.

Synergistic oxidative removal of sulfamethoxazole using Ferrate(VI) and peroxymonosulfate

The synergic effect of Ferrate(VI) (Fe(VI)) and peroxymonosulfate (PMS) on sulfamethoxazole (SMX) oxidative removal was investigated in this study. The sulfate radicals (SO4−), generated through Fe(VI)-mediated activation of PMS, have been demonstrated as an effective oxidant for the removal of SMX. However, the scavenging experiments have suggested that various iron species, i.e., Fe(VI), Fe(V), and Fe(IV) play a vital role in facilitating efficient SMX oxidation. pH is a crucial parameter in this system because the involved species, including Fe(VI), PMS, and SMX, have acid-base dissociation points. Accordingly, the optimal pH value for the SMX removal was achieved at pH = 6, and the addition of PMS enhanced the degradation efficiency of Fe(VI) at all pH-operating conditions. Several oxidation products of SMX were identified, including sulfanilamide (SAM), 3-amino-5-methylisoxazole (AMI), and other potentially hydroxylated byproducts. Characterization studies on solid particles collected after the Fe(VI)/PMS treatment revealed structural changes during SMX oxidation, and the potential contributions of Fe2O3 or Fe(OH)3 to the oxidation mechanism were evaluated accordingly. While the removal efficiency in a river matrix was slightly reduced, the presence of inorganic ions had minimal impact on SMX removal, which confirms the high potential of the Fe(VI)/PMS technology to operate in environmentally relevant conditions.

Potassium peroxoborate: A sustained-released reactive oxygen carrier with enhanced PAHs contaminated soil remediation performance

Seeking for a safe, efficient, inexpensive, and eco-friendly oxidizer is always a big challenge for in-situ chemical oxidation (ISCO) technology. This study adopted the potassium peroxoborate (PPB), a novel peroxide, for soil remediation for the first time. PPB based chemical oxidation system (PPB-CO) could efficiently degrade polycyclic aromatic hydrocarbons (PAHs) without other reagents added, reaching 72.1 %, 64.2 %, and 50.0 % removal rates for naphthalene, phenanthrene, and pyrene after 24 h reaction, respectively. The superior total PAHs removal efficiency (60.6 %) was 3.6–4.7 times higher than that of other commercial peroxides (2Na2CO3•3H2O, CaO2, and H2O2). Mechanism analysis revealed that varieties of reactive oxygen species (ROS) can be generated by PPB through Fenton-like or non-Fenton routines, including H2O2, perborates species, O2•−, •OH, and 1O2. The sustainable generation of H2O2 reduced the disproportionation effect of H2O2 by 86 %, significantly improving the utilization rate. Moreover, sandbox experiments and actual contaminated soil remediation experiments verified the feasibility of PPB-CO in a real polluted site. This work provides a novel strategy for effectively soil remediation, highlighting the selection and application of new oxidants.

Sustained oxidation of Tea-Fe(III)/H2O2 simultaneously achieves sludge reduction and carbamazepine removal: The crucial role of EPS regulation

Establishing an economic and sustained Fenton oxidation system to enhance sludge dewaterability and carbamazepine (CBZ) removal rate is a crucial path to simultaneously achieve sludge reduction and harmless. Leveraging the principles akin to "tea making", we harnessed tea waste to continually release tea polyphenols (TP), thus effectively maintaining high level of oxidation efficiency through the sustained Fenton reaction. The results illustrated that the incorporation of tea waste yielded more favorable outcomes in terms of water content reduction and CBZ removal compared to direct TP addition within the Fe(III)/hydrogen peroxide (H2O2) system. Concomitantly, this process mainly generated hydroxyl radical (•OH) via three oxidation pathways, effectively altering the properties of extracellular polymeric substances (EPS) and promoting the degradation of CBZ from the sludge mixture. The interval addition of Fe(III) and H2O2 heightened extracellular oxidation efficacy, promoting the desorption and removal of CBZ. The degradation of EPS prompted the transformation of bound water to free water, while the formation of larger channels drove the discharge of water. This work achieved the concept of treating waste with waste through using tea waste to treat sludge, meanwhile, can provide ideas for subsequent sludge harmless disposal.

Green Synthesis of Au-Ni Bimetallic Nanoparticles using Aqueous Extract of Coccinia grandis (L.) Voigt and their Catalytic Activity in Oxidation of Alcohols

Background: In recent years, bimetallic nanoparticles have gained remarkable attention due to their excellent physical and chemical properties. Especially, bimetallic nanoparticles are found to be highly efficient as catalysts in many important organic transformations. background: In recent years, bimetallic nanoparticles have gained remarkable attention due to their excellent physical and chemical properties. Especially, bimetallic nanoparticles are found to be highly efficient as catalyst in many important organic transformations. Objective: The objective of the present work involves green synthesis of Au-Ni bimetallic nanoparticles using plant extract as the bio-reductant and to evaluate their catalytic efficiency in oxidation of alcohols. Methods: The experiment involves a simple and eco-friendly protocol for synthesis of Au-Ni bi-metallic as well as their corresponding monometallic nanoparticles that involves the use of aqueous fruit seed extract of Coccinia grandis(L.) Voigt as the bio-reductant and tannic acid as the bio-stabilizer. The synthesized nanoparticles were characterized by using XRD, TEM, FTIR, TGA etc., and their catalytic activity was evaluated for oxidation of alcohols. Results: The synthesized bimetallic nanoparticles have shown excellent catalytic activity towards aqueous phase oxidation of alcohols to aldehydes under ambient reaction conditions. Furthermore, the results have revealed better effective performance of the bimetallic nanoparticles over the corresponding monometallic nanoparticles of gold and nickel, establishing the synergic influence of the two metals. Another attractive feature of this work is that the Au-Ni bimetallic nano-particles could be recycled and reused up to four catalytic cycles without any significant decline in product yield. Conclusion: The green synthesized bimetallic Au-Ni nanoparticles have shown excellent catalytic activity toward the oxidation of alcohols in aqueous media under ambient reaction conditions. In addition, the nanoparticles are found to be successfully recyclable upto four catalytic cycles.

Palladium-charcoal Catalyzed Direct Esterification of Aldehydes to Esters by NaIO4

Abstract:: An efficient direct oxidation method was developed to oxidize some aromatic and aliphatic aldehydes to esters by the dual utilization of NaIO4 and Pd-C. At ambient conditions, various aldehydes were employed in a clean esterification reaction to afford numerous esters in good to excellent yields. By this adopted method, some multifunctional aldehydes, high-energy-containing aromatic and unsaturated aldehydes, were advantageously oxidized to esters without noticeable difficulties. Moreover, no over-oxidation occurred to alcohols, and most byproducts were not formed during this oxidation process. Conventional and some modern methods lag behind owing to their easier operability and easy work-up process. This investigation has proven that the required oxidant (NaIO4) or catalyst (Pd-C) is useless to employ in excess, although some current methods utilize hugely expensive reagents for such conversions. Mundane reaction set-up, easy product recovery technique, non-toxic catalyst, and cheap and available starting materials are the noteworthy advantages of this method.

Recyclable porous core-shell Mn-Co-O flame retardant for improving flame retardancy and smoke suppression of epoxy resin

The development of metal oxide flame retardants that are easy to synthesize, efficient, and recyclable would be more beneficial to circular economy. In this work, a porous core-shell Mn3CoOx was developed to efficiently reduce heat, smoke as well as hazardous gas during the combustion of epoxy resin (EP). Compared with pure EP, the peak heat release rate (pHRR), total heat release (THR), peak smoke production rate (pSPR), total smoke production (TSP), peak CO production rate (pCOPR), and peak CO2 production rate (pCO2PR) of EP/Mn3CoOx are reduced by 47.5 %, 21.5 %, 34.6 %, 17.6 %, 58.6 %, and 55.4 %, respectively. It has been shown that Mn3CoOx not only catalyzes the formation of high-quality char layer but also effectively catalyzes the conversion of hazardous gas products into CO2. Recovery experiments of Mn3CoOx filler in EP composites show that the recovery of Mn3CoOx can reach 90.0 %. This work provides insights into the design of efficient metal oxide flame retardants and ideas for the development of recycled flame retardants.

Synthesis and characterization of new nanocomposite PW11Ba@BaMnO2 as an efficient nanocatalyst for water oxidation process

In this study, a new nanocomposite was synthesized using the sol-gel method by immobilizing of mono-substituted Keggin-type polyoxometalate containing barium (PW11Ba) on the surface of barium manganese oxide (BaMnO2) nanoceramics. The corresponding nanocomposite, denoted as PW11Ba@BaMnO2, was utilized as an effective heterogeneous catalyst in the water splitting for O2 evolution reaction (OER). The characterization of the PW11Ba@BaMnO2 nanocatalyst was performed using various techniques, such as FT-IR, UV–vis, XRD, SEM, and EDX methods. After the successful preparation of the PW11Ba@BaMnO2, its catalytic performance in the OER process was evaluated at different pH values (pH = 7 and 9) using ceric ammonium nitrate (CAN) as an efficient oxidant. The as-prepared nanocomposite exhibited remarkable turnover frequency (TOF), turnover number (TON), and O2 evolution values of 0.702 mmolO2molCo.s, 971.68 mmolO2molCo, and 0.0014 mgO2L.S at pH = 9, respectively. Moreover, the influence of CAN concentration, pH value, and the amounts of KOH and BaCl2 on the OER process was assessed, and a plausible reaction mechanism was suggested. In this research, the PW11Ba@BaMnO2 nanocatalyst has provided valuable insights on the design of other catalysts for water oxidation reactions and beyond.

Magnesium Oxide (MgO) as a Sustainable Catalyst for Biodiesel Production from Waste Cooking Oil: A Comparative Study with KOH

The present study investigates the efficiency of magnesium oxide (MgO) as a heterogeneous catalyst in the production of biodiesel from waste cooking oil (WCO), putting an emphasis on its environmental benefits, cost-effectiveness, and operational efficacy. Through a series of experiments, we optimized the reaction conditions, including catalyst concentration, reaction temperature, and ethanol to WCO molar ratio, to achieve a high biodiesel yield. The results indicate that an optimal MgO concentration of 3 wt%, a reaction temperature of 65 °C, and a molar ratio of 9:1 result in the highest biodiesel production efficiency. Additionally, MgO demonstrated significant reusability without a decrease in performance, underscoring its economic and environmental advantages. Comparative analysis revealed that MgO outperforms conventional KOH catalysts in terms of yield, purity, and sustainability. Our study suggests future research directions, including the optimization of MgO preparation methods and the exploration of co-catalyst systems to further enhance biodiesel production from WCO. This research contributes to the development of sustainable biodiesel production methods, aligning with global energy and environmental goals.

Elimination of Chlorella using peracetic acid activated by dielectric barrier discharge plasma: Mechanism and cell deactivation process

Excessive proliferation of algae in water depletes dissolved oxygen, resulting in the demise of aquatic life and environmental damage. This study delves into the effectiveness of the dielectric barrier discharge (DBD) plasma activated peracetic acid (PAA) system in deactivating Chlorella. Within 15 min, the algae removal effectiveness reached 89 % under ideal trial conditions. DBD plasma activation of PAA augmented the concentration of reactive species such as ·OH, 1O2, and organic radicals (RO·) in the solution, which are involved in the process of cell inactivation. Reactive oxygen species (ROS) within Chlorella cells continued to rise as a result of treatment-induced damage to the morphological structure and cell membrane of the organism. DNA and chlorophyll-a (Chl-a), were oxidized and destroyed by these invasive active compounds. This study presents an efficient advanced oxidation method to destroy algal cells and adds an alternative strategy for algal control in areas where eutrophication occurs.

Substitution of both histidines in the active site of yeast alcohol dehydrogenase 1 exposes underlying pH dependencies

Histidine residues 44 and 48 in yeast alcohol dehydrogenase (ADH) bind to the coenzymes NAD(H) and contribute to catalysis. The individual H44R and H48Q substitutions alter the kinetics and pH dependencies, and now the roles of other ionizable groups in the enzyme were studied in the doubly substituted H44R/H48Q ADH. The substitutions make the enzyme more resistant to inactivation by diethyl pyrocarbonate, modestly improve affinity for coenzymes, and substantially decrease catalytic efficiencies for ethanol oxidation and acetaldehyde reduction. The pH dependencies for several kinetic parameters are shifted from pK values for wild-type ADH of 7.3–8.1 to values for H44R/H48Q ADH of 8.0–9.6, and are assigned to the water or alcohol bound to the catalytic zinc. It appears that the rate of binding of NAD+ is electrostatically favored with zinc-hydroxide whereas binding of NADH is faster with neutral zinc-water. The pH dependencies of catalytic efficiencies (V/EtKm) for ethanol oxidation and acetaldehyde reduction are similarly controlled by deprotonation and protonation, respectively. The substitutions make an enzyme that resembles the homologous horse liver H51Q ADH, which has Arg-47 and Gln-51 and exhibits similar pK values. In the wild-type ADHs, it appears that His-48 (or His-51) in the proton relay systems linked to the catalytic zinc ligands modulate catalytic efficiencies.

Simultaneous enhancement of charge transfer and surface catalysis through a polymetallic oxide cocatalyst on BiVO4 photoanodes for highly efficient and stable water oxidation

The rate-determining oxygen evolution reaction (OER) always limits the high-efficient conversion of solar energy to green hydrogen fuels through photoelectrocatalytic or photocatalytic water splitting. The high catalytic overpotential and the instability of catalytic center are commonly regarded as the primary factors contributing to the low rate of OER, remaining to be a challenge in the field of water splitting. Herein, a polymetallic oxide cocatalyst (Mo-MnOy/FeCoNiOx) with well-defined electronic and catalytic properties is designed on BiVO4 photoelectrode for highly efficient and stable photoelectrocatalytic water oxidation. The experimental characterization demonstrates that the dual-layer design of Mo-MnOy/FeCoNiOx can significantly optimizes the electronic property of MnOy and FeCoNiOx components, boosting the photogenerated charge transfer between Mo-MnOy/FeCoNiOx cocatalyst and BiVO4 photoelectrode. The density functional theory (DFT) simulation reveals that the Mo sites in Mo-MnOy layer can activate the neighboring surface Mn sites instead of directly serving as the catalytic center, thereby establishing these Mn sites as primary active centers for achieving stable OER. The developed Mo-MnOy/FeCoNiOx/BiVO4 photoelectrode exhibits a current density of 6.18 mA cm−2 with an excellent stability for 30 h at 1.23 VRHE under 1 sun irradiation, exhibiting the excellent activity and durability. This work sheds light on design of high-performance multiple-component water-oxidation cocatalyst on photoanode.

Highly efficient catalytic oxidation of toluene by amorphous/microcrystalline mixed-phase MnO2

Amorphous transition metal oxides exhibit considerable potential in the catalytic oxidation of volatile organic compounds (VOCs) owing to their distinctive surface properties. In this study, we achieved the modulation of the crystalline structure of manganese oxides by employing various C3 alcohols (alcohols with three carbons) with distinct hydroxyl types during the reduction process with potassium permanganate. Subsequently, a series of characterization techniques were employed to assess the catalytic performance of the prepared MnO2 in the oxidation of toluene. Notably, the MnO2-G obtained from glycerol presented excellent catalytic activity (T90 = 219 °C), stability, and water resistance. The unique amorphous/microcrystalline state of MnO2-G exposed more phase boundaries, and the unsaturated coordination structure facilitated the generation of additional defective sites, favoring the adsorption and activation of oxygen. Furthermore, the mixed-crystalline state induced the elevated Mn3+ content on the surface of MnO2-G, leading to elongation of the Mn-O bond due to the pronounced Jahn-Teller effect of Mn3+. Consequently, the synergistic effects of the mixed crystalline state contributed to the efficient catalytic oxidation of toluene at relatively low temperatures. Additionally, the conversion pathway of toluene on MnO2-G was further revealed by in situ DRIFTS.

Highly enhanced direct catalytic oxidation of cyclohexane to adipic acid by prussian blue analogues-derived C, N doped CuCo composite catalysts

The oxidation of cyclohexane to produce adipic acid suffered from the inefficient and polluting two-step process. We introduce the CuCo Prussian blue analogues derived in situ C, N doped CuCo composite catalysts in the selective oxidation of cyclohexane. Due to the in-situ doping of C and N elements in the form of active graphite carbon and pyridine nitrogen, the oxygen vacancy content and the ability to activate oxygen are improved. The one-step efficient catalytic oxidation of cyclohexane to adipic acid was realized due to the excellent electron transfer performance between C, N elements and metals