Oxidative Dehydrogenation Reaction Research Articles

Borocarbonitride Catalyzed Ethylbenzene Oxidative Dehydrogenation: Activity Enhancement via Encapsulation of Mn Clusters inside the Tube.

Borocarbonitride (BCN) catalysts, boasting multiple redox sites, have shown considerable potential in alkane oxidative dehydrogenation (ODH) to olefin molecules. However, their catalytic efficiency still lags behind that of leading commercial catalysts, primarily due to the limited reactivity of oxygen functional groups. In this study, a groundbreaking hybrid catalyst is developed, featuring BCN nanotubes (BCNNTs) encapsulated with manganese (Mn) clusters, crafted through a meticulous supramolecular self-assembly and postcalcination strategy. This novel catalyst demonstrates a remarkable enhancement in activity, achieving 30% conversion and ≈100% selectivity toward styrene in ethylbenzene ODH reactions. Notably, its performance surpasses both pure BCNNTs and those hosting Mn nanoparticles. Structural and kinetic analyses unveil a robust interaction between BCNNTs and the Mn component, substantially boosting the catalytic activity of BCNNTs. Furthermore, density functional theory (DFT) calculations elucidate that BCNNTs encapsulated with Mn clusters not only stabilize key intermediates (─B─O─O─B─) but also enhance the nucleophilicity of active sites through electron transfer from the Mn cluster to the BCNNTs. This electron transfer mechanism effectively lowers the energy barrier for ─C─H cleavage, resulting in a 13% improvement in catalytic activity compared to pure BCNNTs.

Kinetic study of propane ODH on electrospun vanadium oxide-based submicron diameter fiber catalyst

A rigorous kinetic study of the oxidative dehydrogenation (ODH) reaction of propane on a vanadium oxide-based submicron diameter fiber catalyst has been developed. The proposed kinetic model simulates the conversion-selectivity profiles, the surface coverage of the different adsorbed species and the oxidation state of the catalyst for the studied operating conditions of temperature, space–time and inlet partial pressures of propane and oxygen. The activation energy of the rate determining step (RDS), the first hydrogen abstraction from propane, is 104 kJ·mol−1. The model predicts that although the reaction seems to be pseudo-zero order with respect to oxygen in a broad range of conditions, the catalyst may not be fully oxidized during reaction. The accuracy of the model when predicting the oxidation state of the catalyst has been experimentally confirmed by analyzing the catalytic fixed bed after reaction. The reduction degree of the catalyst will depend on its intrinsic chemical nature and reaction conditions, increasing with the space–time and in detriment of the overall reaction rate. Consequently, the propane turnover frequency (TOF) will also depend on the reaction conditions and space–time, even changing along the fixed-bed reactor.

Low temperature catalytic activity of molybdenum promoted two-dimensional boron nitride in propane oxidative dehydrogenation reaction

The catalytic oxidation dehydrogenation of propane to propylene, achieved at low temperatures and with high selectivity on catalysts supported by non-noble metals, exhibits significant potential for a wide range of applications. The performance of boron-based catalysts in ODHP is remarkable; however, there is a dearth of research on their low-temperature range performance. The present study employed a straightforward impregnation method to synthesize a range of Mo/h-BN-γ-Al2O3 catalysts with varying molybdenum loadings, focusing on the comparison between commercial h-BN and h-BN-γ-Al2O3 mixed support. The Mo/h-BN-γ-Al2O3 catalyst demonstrates remarkable low-temperature ODHP activity, with an initial conversion rate of 2.36 % and a propylene selectivity of 96 % at a reaction temperature of 260 ℃, exhibiting good stability over 50 h, the catalytic performance of Mo/h-BN-γ-Al2O3 in the low-temperature range surpasses that of commercial h-BN by a significant margin. Comparative experiments, along with physical and chemical characterization techniques, demonstrate that the incorporation of an appropriate quantity of Mo enhances the catalyst's acidity and redox capability. Furthermore, the synergistic effect between MoOx and BOx promotes low-temperature ODHP. The mechanism underlying the catalyst's low-temperature reaction was investigated using in-situ infrared spectroscopy technology.

Novel Alkane Dehydrogenation Routes via Tailored Catalysts

Alkane dehydrogenation to alkene represents a promising alternative route for conventional petroleum cracking processes heavily reliant on fossil resources. This Concept outlines the latest advancements of novel alkane dehydrogenation routes that offer potential solutions to intrinsic problems existing in routine direct dehydrogenation or oxidative dehydrogenation reactions, including CO2 assisted alkane dehydrogenation, chemical looping alkane oxidative dehydrogenation, dual‐path dehydrogenation and auto‐accelerated multiple alkane dehydrogenation route. These novel reaction routes exhibit unique advantages in enhancing the activity, selectivity and stability of the alkane dehydrogenation reaction system. The rational design of novel catalysts and proper choice of the reaction condition that well‐fitted these reaction routes is the key for achieving highly efficient and stable alkane dehydrogenation process. These present examples in this manuscript also highlight the importance of fundamental in‐depth understandings on the mechanism and structure‐function relations, which is the foundation for developing novel alkane dehydrogenation routes for practical applications.

Electrochemical Activation of Surface Oxygen for Efficient Oxidative Dehydrogenation Reaction at Elevated Temperatures

Electrochemical Activation of Surface Oxygen for Efficient Oxidative Dehydrogenation Reaction at Elevated Temperatures

N, P codoped hollow carbon prisms for efficient oxidative dehydrogenation reaction with both enhanced activity and selectivity

Carbon materials have stimulated tremendous interest in oxidative dehydrogenation (ODH) of alkane to olefin molecules at low temperature. Unfortunately, its further development has been seriously hindered due to the unsatisfactory catalytic performance. To tackle these challenges, nitrogen and phosphorus codoped hollow carbon prisms (NPC) are designed with controllable surface functional groups through supramolecular pre-assembly and substitution reaction from guanine and hexachlorotriphosphazene. The resultant catalysts can achieve both high catalytic activity (63 % conversion) and styrene selectivity (90 %) in ODH of ethylbenzene, outerperforming previous reported carbon-based catalysts. Structural characterizations, kinetics measurements and theoretical results unravel that nitrogen doping can promote nucleophilicity of –CO, thus improving the catalytic activity. The phosphorus doping not only changes reaction rate-determining step from activation of O2 in N-doped carbon to activation of –C–H bond of EB in N,P-codoped carbon, but also inhibits the formation of electrophilic oxygen species, which enhances selectivity of styrene. The current work provides a facile strategy for preparation of functional NPC catalyst and physical–chemical insights on the structure–activity relationship of NPC catalysts, paving the way for further development of the highly efficient non-metallic catalytic systems.

Effect of Zn–Brønsted acid in zeolites on ethane dehydrogenation with tandem reverse water gas shift reaction

The abundant hydroxyl groups and tunable Brønsted acid sites (BAS) of MWW zeolites were used to introduce and anchor zinc active sites, preventing the volatilization and deactivation of ZnOx due to its reduction to Zn0. Fabricated Zn/MWW catalysts effectively promoted ethane dehydrogenation (EDH) and tandem complex reaction of dehydroaromatization and CO2 oxidative dehydrogenation at high temperatures. Brønsted Zn/MWW catalysts containing [ZnOH]+ were prepared via incipient wetness impregnation using liquid ion exchange whereas those containing [ZnOx]2+ were prepared via atom planting using the gas dechlorination reaction. Additionally, the different acidic sites in MWW zeolites effectively affected the interaction between ZnCl2 and hydroxyl groups during the dechlorination reaction. The catalytic EDH performance of [ZnOx]2+ active sites generated using stronger BASs was higher than that of [ZnOx]2+ active sites generated via weaker BASs and silanol. The synergetic effect of Zn and BASs in zeolites catalyzed dehydroaromatization can be suppress by control the [ZnOH]+ location in the external surface of zeolite or by homogenous consumption of the BAS by [ZnOx]2+. Furthermore, [ZnOH]+ and [ZnOx]2+ catalyzed the reverse water gas shift reaction, accelerated the rate-limiting step of EDH via the CO2 oxidative EDH reaction, inhibited the selectivity of aromatics, and consumed coke via the Boudouard reaction.

Deep Potential Molecular Dynamics Study of Propane Oxidative Dehydrogenation.

Oxidative dehydrogenation (ODH) of light alkanes is a key process in the oxidative conversion of alkanes to alkenes, oxygenated hydrocarbons, and COx (x = 1,2). Understanding the underlying mechanisms extensively is crucial to keep the ODH under control for target products, e.g., alkenes rather than COx, with minimal energy consumption, e.g., during the alkene production or maximal energy release, e.g., during combustion. In this work, deep potential (DP), a neural network atomic potential developed in recent years, was employed to conduct large-scale accurate reactive dynamic simulations. The model was trained on a sufficient data set obtained at the density functional theory level. The intricate reaction network was elucidated and organized in the form of a hierarchical network to demonstrate the key features of the ODH mechanisms, including the activation of propane and oxygen, the influence of propyl reaction pathways on the propene selectivity, and the role of rapid H2O2 decomposition for sustainable and efficient ODH reactions. The results indicate the more complex reaction mechanism of propane ODH than that of ethane ODH and are expected to provide insights in the ODH catalyst optimization. In addition, this work represents the first application of deep potential in the ODH mechanistic study and demonstrates the ample advantages of DP in the study of mechanism and dynamics of complex systems.

Biodegradation of penicillin G sodium by Sphingobacterium sp. SQW1: Performance, degradation mechanism, and key enzymes

Biodegradation is an efficient and cost–effective approach to remove residual penicillin G sodium (PGNa) from the environment. In this study, the effective PGNa–degrading strain SQW1 (Sphingobacterium sp.) was screened from contaminated soil using enrichment technique. The effects of critical operational parameters on PGNa degradation by strain SQW1 were systematically investigated, and these parameters were optimized by response surface methodology to maximize PGNa degradation. Comparative experiments found the extracellular enzyme to completely degrade PGNa within 60 min. Combined with whole genome sequencing of strain SQW1 and LC–MS analysis of degradation products, penicillin acylase and β–lactamase were identified as critical enzymes for PGNa biodegradation. Moreover, three degradation pathways were postulated, including β–lactam hydrolysis, penicillin acylase hydrolysis, decarboxylation, desulfurization, demethylation, oxidative dehydrogenation, hydroxyl reduction, and demethylation reactions. The toxicity of PGNa biodegradation intermediates was assessed using paper diffusion method, ECOSAR, and TEST software, which showed that the biodegradation products had low toxicity. This study is the first to describe PGNa–degrading bacteria and detailed degradation mechanisms, which will provide new insights into the PGNa biodegradation.

Cobalt catalyzed ethane dehydrogenation to ethylene with CO2: Relationships between cobalt species and reaction pathways

TiO2, ZrO2 and a series of TiO2-ZrO2 (TxZ1, x means the atomic ratio of Ti/Zr = 10, 5, 1, 0.2 and 0.1) composite oxide supports were prepared through co-precipitation, and then 3 wt% Co was loaded through wetness impregnation methods. The obtained 3 wt% Co/TiO2 (3CT), 3 wt% Co/ZrO2 (3CZ) and 3 wt% Co/TxZ1 (3CTxZ1) catalysts were evaluated for the oxidative ethane dehydrogenation reaction with CO2 (CO2-ODHE) as a soft oxidant. 3CT1Z1 catalyst exhibits excellent catalytic properties, with C2H4 yield, C2H6 conversion and CO2 conversion about 24.5 %, 33.8 % and 18.0 % at 650 °C, respectively. X-Ray Diffraction (XRD), in-situ Raman, UV–vis diffuse reflectance spectra (UV–vis DRS), H2 temperature-programmed reduction (H2-TPR), Electron paramagnetic resonance (EPR) and quasi in-situ X-ray Photoelectron Spectroscopy (XPS) have been utilized to thoroughly characterize the investigated catalysts. The results revealed that 3CT1Z1 produced TiZrO4 solid solution with more metal defect sites and oxygen vacancies (Ov), promoting the formation of Co2+-TiZrO4 structure. Furthermore, the presence of Ov and Ti3+can facilitate the high dispersion and stabilization of Co2+, as well as suppressing the severe reduction of Co2+, leading to superior ethane oxidative dehydrogenation activity. Besides, less Co0 is beneficial to ODHE reaction, because of its promotion effects for reverse water gas shift reaction; however, more Co0 results in dry reforming reaction (DRE). This work will shed new lights for the design and preparation of highly efficient catalysts for ethylene production.

Photodynamic Modulation of Endoplasmic Reticulum and Mitochondria Network Boosted Cancer Immunotherapy.

Immunogenic cell death (ICD) represents a promising approach for enhancing tumor therapy efficacy by inducing antitumor immune response. However, current ICD inducers often have insufficient endoplasmic reticulum (ER) enrichment and ineffectiveness in tumor immune escape caused by ER-mitochondria interaction. In this study, a kind of photoactivatable probe, THTTPy-PTSA, which enables sequential targeting of the ER and mitochondria is developed. THTTPy-PTSA incorporates p-Toluenesulfonamide (PTSA) for ER targeting, and upon light irradiation, the tetrahydropyridine group undergoes a photo oxidative dehydrogenation reaction, transforming into a pyridinium group that acts as a mitochondria-targeting moiety. The results demonstrate that THTTPy-PTSA exhibits exceptional subcellular translocation from the ER to mitochondria upon light irradiation treatment, subsequently triggers a stronger ER stress response through a cascade-amplification effect. Importantly, the augmented ER stress leads to substantial therapeutic efficacy in a 4T1 tumor model by eliciting the release of numerous damage-associated molecular patterns, thereby inducing evident and widespread ICD, consequently enhancing the antitumor immune efficacy. Collectively, the findings emphasize the pivotal role of photodynamic modulation of the ER-mitochondria network, facilitated by THTTPy-PTSA with precise spatial and temporal regulation, in effectively bolstering the antitumor immune response. This innovative approach presents a promising alternative for addressing the challenges associated with cancer immunotherapy.

Practical mutual transformation of azobenzene and hydrazobenzene using porous BN supported Cu nanoparticles as a redox catalyst

Azobenzene and hydrazobenzene compounds are essential intermediates for synthesizing pharmaceuticals and dyes. Meanwhile, the hydrazobenzene/azobenzene couple is a potential hydrogen storage system when both the dehydrogenation of hydrazobenzene and the hydrogenation of azobenzenes can be achieved under mild reaction conditions. In this work, we report an entirely mutual transformation of azobenzene and hydrazobenzene under very mild conditions using porous BN supported Cu nanoparticles (Cu/PBN) as the catalyst for the first time. Direct oxidative dehydrogenation reaction proceeded in the open air with the removal of molecular hydrogen as the by-product and a wide range of hydrazobenzenes readily undergoes dehydrogenation, resulting in an excellent yield of the corresponding azobenzene.

CO2-assisted oxidative dehydrogenation of ethane to ethylene over the ZnO-ZrO2 catalyst

The ZnO-ZrO2 catalyst was prepared by the deposition-precipitation method using ZrO2 as the carrier obtained from calcining commercial zirconium hydroxide (Zr(OH)4). And the catalytic performance was evaluated at 873 K in CO2-assisted ethane oxidative dehydrogenation reaction (CO2-ODHE). The physical-chemical properties and morphology were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Raman spectra, High-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectra (XPS), CO2 temperature-programmed desorption (CO2-TPD). The results show that ZnO were doped into the surface lattice of ZrO2 on the 5%ZnO-ZrO2 catalyst, generating highly dispersed ZnO species and oxygen-deficient regions on catalyst surface. 5%ZnO-ZrO2 catalyst could selectively breaking C–H bond instead of C–C bond, delivering excellent catalytic performance. 210 μmol/(gcat·min) of C2H4 formation rate could compare favorably with the data reported on noble metal and transition metal carbides. Additionally, the possible mechanism is discussed.

DESIDROGENAÇÃO CATALÍTICA OXIDATIVA DO ETANO UTILIZANDO CO2: UMA MINI REVISÃO

As a consequence of the greenhouse effect, there is a growing concern worldwide to reduce the amount of atmospheric carbon dioxide and a continuous effort by the scientific community to expand its use in various applications. Recently, CO2 has been used as an alternative, being applied as a light oxidant in the ethane oxidative dehydrogenation reaction, enabling new routes to obtain ethylene that are more efficient and economical than the current ones. Thus, the oxidative dehydrogenation of ethane with carbon dioxide stands out as one of the most promising alternatives, as it is an economical and ecological process, consuming one of the greenhouse gases. To analyze the literature on the relevance of the catalytic oxidative dehydrogenation reaction of ethane as an alternative route to ethylene production. This is a bibliographic review that used as source the databases of ELSEVIER, SPRINGER and CAPES from the descriptors "ODHE", "Oxidative catalytic dehydrogenation with CO2" and "ethene". Using the inclusion criteria, 50 articles in English and Portuguese published from 2012 to 2023 and a technical book were analyzed. CO2 is a promising alternative for the oxidative dehydrogenation reaction of ethane with O2, which suffers from catalyst deactivation due to coke formation and reducing selectivity to the main product. From the use of CO2 as an oxidant in the reaction, we have the advantage of producing active oxygen species, reducing coking and increasing selectivity. However, the great challenge is the development of catalysts that are active and selective to ethylene, with nickel oxide and cerium oxide emerging as promising alternatives, with high catalytic activity and favoring the redox cycle.

Role of oxygen transfer and surface reaction in catalytic performance of VOx-Ce1–xZrxO2 for propane dehydrogenation

The bulk oxygen transfer and surface reaction as important parts of the chemical looping-related process are crucial for the rational design of new redox catalysts. This paper describes an experimental study on the effect of bulk oxygen transfer and surface reaction in Ce1–xxO2 supported VOx redox catalysts for the chemical looping oxidative propane dehydrogenation reaction. It was found that the introduction of Zr dictates the reaction performance of the redox catalyst by modulating the bulk oxygen transfer and surface reaction. The kinetic study reveals that the instantaneous reduction rate of the redox catalysts is determined by the H-abstraction step in the surface reaction. The introduction of Zr can reduce the activation energy of the H-abstraction step, which leads to the enhancement of the instantaneous reduction rate. Meanwhile, the oxygen supply capacity of the cerium oxide is increased by Zr, allowing the surface reaction to proceed over longer durations. Furthermore, the reaction model derived from the kinetics study is validated using a number of (quasi) in situ techniques. This study provides fundamental insights into the role of bulk oxygen transfer and surface reaction in chemical looping or related process.

Structural reconstruction of iron oxide induces stable catalytic performance in the oxidative dehydrogenation of n-butane to 1,3-butadiene

The CO2-assisted oxidative dehydrogenation of n-butane to 1,3-C4H6 offers a perspective process for producing valuable chemicals while simultaneously utilizing CO2. In this work, iron-based ZnFe2Ox and Fe2O3 catalysts with high 1,3-C4H6 selectivity were prepared and their corresponding structure–activity relationships were investigated in detail. On basis of the in situ spectroscopic characterization, hydrogen-assisted CO2 activation pathway was captured. Kinetic studies show that Fe2O3 catalyst displays a higher reaction order depending on CO2 concentration than that of ZnFe2Ox catalyst. Fe2O3 is evidenced to serve as an effective mediator for oxygen exchange between CO2 and n-butane based on temperature-programmed experiments and deactivation kinetics analysis. Rapid deactivation is observed over ZnFe2Ox due to its strong CO2 adsorption ability, which triggers the reforming reaction accompanied by severe coke deposition. Interestingly, self-healing phenomena for catalytic performance are found on Fe2O3 catalyst after several test cycles. The reaction/regeneration cycles are proved to drive the surface reconstruction which greatly enhance its resistance to over reduction and coking. This study provides a fundamental insight into Fe-based catalysts in the CO2-assisted oxidative dehydrogenation reactions.

Conversion and impact of dissolved organic matters in a heterogeneous catalytic peroxymonosulfate system for pollutant degradation.

Dissolved organic matters (DOM) are widely present in different water sources, causing significant effects on water treatment processes. Herein, the molecular transformation behavior of DOM during peroxymonosulfate (PMS) activation by biochar for organic degradation in a secondary effluent were comprehensively analyzed. Evolution of DOM was identified and inhibition mechanisms to organic degradation were elucidated. DOM underwent oxidative decarbonization (e.g., -C2H2O, -C2H6, -CH2 and -CO2), dehydrogenation (-2H) and dehydration reactions by ·OH and SO4·-. N and S containing compounds witnessed deheteroatomisation (e.g., -NH, -NO2+H, -SO2, -SO3, -SH2), hydration (+H2O) and N/S oxidation reactions. Among DOM, CHO-, CHON-, CHOS-, CHOP- and CHONP-containing molecules showed moderate inhibition while condensed aromatic compounds and aminosugars exhibited strong and moderate inhibition effects on contaminant degradation. The fundamental information could provide references for the rational regulation of ROS composition and DOM conversion process in a PMS system. This in turn offered theoretical guidance to minimize the interference of DOM conversion intermediates on PMS activation and degradation of target pollutants.

Catalytic Performances of Co/TiO2 Catalysts in the Oxidative Dehydrogenation of Ethane to Ethylene: Effect of CoTiO3 and Co2TiO4 Phase Formation

Co/TiO2 catalysts with different cobalt loadings (3.8, 7.5 and 15 wt%) were prepared by impregnation method of Co(NO3)2 6H2O over titania. Samples containing Co(NO3)2·6H2O and TiO2 in stoichiometric proportions in order to obtain CoTiO3 and Co2 TiO4 phases were also synthesized. The effect of the calcination treatment at two different temperatures, 550 and 1150 °C, was investigated. Characterizations by several techniques, such as XRD, UV–vis–NIR, DRS, Raman and XPS, were carried out. XRD showed the coexistence of three phases: CoTiO3; Co2TiO4 and Co3O4 after calcination at 550 °C, while calcination at high temperature (1150 °C) led to single-phase systems (CoTiO3 or Co2TiO4). Diffuse reflection and XPS spectroscopy showed that divalent cobalt occupies octahedral sites in the ilmenite phase, and both tetrahedral and octahedral sites in the spinel phase. The catalytic performances of the prepared catalysts were evaluated in the oxidative dehydrogenation reaction (ODH) of ethane to ethylene, as a function of the Co content for Co/TiO2 catalysts and as a function of the calcination temperatures for the CoTiO3 and Co2TiO4 phases. Co(7.5)/TiO2 was the most active, although the conversion of ethane decreased in the first 150 min of the reaction, reaching values comparable to those of Co2TiO4 and CoTiO3; however, Co(7.5)/TiO2 was confirmed as having the best selectivity to ethylene in comparison with the bulk phases, CoTiO3 and Co2TiO4. The influence of the reaction mixture composition, specifically the presence of water, at different percentages, was investigated. There is a decrease in the overall ethane conversion and an increase in the ethylene selectivity when the percentage of water increases. This behavior can likely be attributed to an increase in the surface concentration of hydroxyl species (OH), resulting in heightened surface acidity.

Dehydrogenation of methylcyclohexane using solid oxide fuel cell – A smart energy conversion

Dehydrogenation of methylcyclohexane (MCH), a hydrogen carrier, is investigated using a solid oxide fuel cell (SOFC). When an SOFC is operated with a cell temperature of 420 °C and a current density of 16 mA cm−2, toluene and benzene, the products of MCH’s dehydrogenation reaction, are observed, with a molar ratio of 94:6. When the cell is operated at 490 °C and 90 mA cm−2, in addition of toluene and benzene, 1,4-dioxane is formed at a molar ratio of >86%, indicating an oxidative dehydrogenation reaction of MCH. These findings indicate that an SOFC successfully extracts electrons directly from MCH and generates electricity by utilizing the SOFC’s oxygen ion conduction function. The energy required for this process is expected to be less than that required for conventional MCH dehydrogenation. Furthermore, we reveal that SOFCs can be applied to the oxygen displacement reaction of benzene rings.

Unravelling the role of boron dopant in borocarbonitirde catalytic dehydrogenation reaction

Borocarbonitride (BCN) materials are newly developed metal-free catalytic materials exhibiting high selectivity in oxidative dehydrogenation (ODH) of alkanes. However, the in-depth understandings on the role of boron (B) dopants and the intrinsic activities of –C=O and –B–OH still remain unknown. Herein, we report a series of BCN materials with regulable B content and surface oxygen functional groups via self-assembly and pyrolysis of guanine and boric acid. We found that the B/C ratio is the key parameter to determine the activity of ODH and product distribution. Among them, the high ethylbenzene conversion (∼57%) and styrene selectivity (∼83%) are achieved in ODH for B1CN. The styrene selectivity can be improved by increasing of B/C ratio and this value reaches near 100% for B5CN. Structural characterizations and kinetic measurements indicate that –C=O and –B–OH dual sites on BCN are real active sites of ODH reaction. The intrinsic activity of –C=O (5.556 × 10−4 s−1) is found to be 23.7 times higher than –B–OH (0.234 × 10−4 s−1) site. More importantly, we reveal that the deep oxidation to undesirable CO2 occurs on –C=O rather than –B–OH site, and B dopant in BCN materials can reduce the nucleophilicity of –C=O site to eliminate the CO2 emission. Overall, the present work provides a new insight on the structure–function relationship of the BCN catalytic systems.