Catalytic Destruction Research Articles

Spontaneous Molecular Bromine Production in Sea-Salt Aerosols.

Bromine chemistry is responsible for the catalytic ozone destruction in the atmosphere. The heterogeneous reactions of sea-salt aerosols are the main abiotic sources of reactive bromine in the atmosphere. Here, we present a novel mechanism for the activation of bromide ions (Br-) by O2 and H2O in the absence of additional oxidants. The laboratory and theoretical calculation results demonstrated that under dark conditions, Br-, O2 and H3O+ could spontaneously generate Br and HO2 radicals through a proton-electron transfer process at the air-water interface and in the liquid phase. Our results also showed that light and acidity could significantly promote the activation of Br- and the production of Br2. The estimated gaseous Br2 production rate was up to 1.55×1010 molecules cm-2 ⋅ s-1 under light and acidic conditions; these results showed a significant contribution to the atmospheric reactive bromine budget. The reactive oxygen species (ROS) generated during Br- activation could promote the multiphase oxidation of SO2 to produce sulfuric acid, while the increase in acidity had a positive feedback effect on Br- activation. Our findings highlight the crucial role of the proton-electron transfer process in Br2 production; here, H3O+ facilitates the activation of Br- by O2, serves as a significant source of atmospheric reactive bromine and exerts a profound impact on the atmospheric oxidation capacity.

Beyond self-healing: stabilizing and destabilizing photochemical adjustment of the ozone layer

Abstract. The ozone layer is often noted to exhibit self-healing, whereby depletion of ozone aloft induces ozone increases below, explained as resulting from enhanced ozone production due to the associated increase in ultraviolet (UV) radiation below. Similarly, ozone enhancement aloft can reduce ozone below (reverse self-healing). This paper considers self-healing and reverse self-healing to manifest a general mechanism we call photochemical adjustment, whereby ozone perturbations lead to a downward cascade of anomalies in UV and ozone. Conventional explanations for self-healing imply that photochemical adjustment is stabilizing, damping perturbations towards the surface. However, photochemical adjustment can be destabilizing if the enhanced UV disproportionately increases the ozone sink, as can occur if the enhanced UV photolyzes ozone to produce atomic oxygen, which speeds up catalytic destruction of ozone. We analyze photochemical adjustment in two linear ozone models (Cariolle v2.9 and LINOZ), finding that (1) photochemical adjustment is destabilizing above 40 km in the tropical stratosphere and (2) self-healing often represents only a small fraction of the total photochemical stabilization. The destabilizing regime above 40 km is reproduced in a much simpler model: the Chapman cycle augmented with destruction of O and O3 by generalized catalytic cycles and transport (the Chapman+2 model). The Chapman+2 model reveals that photochemical destabilization occurs where the ozone sink is more sensitive than the source to perturbations in overhead column ozone, which is found to occur when the window of overlapping absorption by O2 and O3 is optically unsaturated, i.e., when overhead slant column ozone is below approximately 1018 molec. cm−2.

Spontaneous Molecular Bromine Production in Sea‐Salt Aerosols

AbstractBromine chemistry is responsible for the catalytic ozone destruction in the atmosphere. The heterogeneous reactions of sea‐salt aerosols are the main abiotic sources of reactive bromine in the atmosphere. Here, we present a novel mechanism for the activation of bromide ions (Br−) by O2 and H2O in the absence of additional oxidants. The laboratory and theoretical calculation results demonstrated that under dark conditions, Br−, O2 and H3O+ could spontaneously generate Br and HO2 radicals through a proton–electron transfer process at the air–water interface and in the liquid phase. Our results also showed that light and acidity could significantly promote the activation of Br− and the production of Br2. The estimated gaseous Br2 production rate was up to 1.55×1010 molecules cm−2 ⋅ s−1 under light and acidic conditions; these results showed a significant contribution to the atmospheric reactive bromine budget. The reactive oxygen species (ROS) generated during Br− activation could promote the multiphase oxidation of SO2 to produce sulfuric acid, while the increase in acidity had a positive feedback effect on Br− activation. Our findings highlight the crucial role of the proton‐electron transfer process in Br2 production; here, H3O+ facilitates the activation of Br− by O2, serves as a significant source of atmospheric reactive bromine and exerts a profound impact on the atmospheric oxidation capacity.

Strong water-resistant Co-Mn solid solution derived from bimetallic metal–organic frameworks for catalytic destruction of toluene

The construction of Co-Mn mixed metal oxides catalysts derived from bimetallic MOFs has great significance for catalytic destruction of toluene. Hence, a series of CoaMnbOx-MOFs with different physicochemical properties were successfully synthesized via pyrolysis of Co-Mn bimetallic MOFs. Attributing to the higher specific surface area, more active sites (Co3+ and Mn3+), stronger reducibility and abundant defect sites, the as-prepared Co1Mn1Ox-MOFs dispalyed an optimal catalytic performance, especially the excellent water vapor resistance. The result of the In Situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy demonstrated that toluene can be degraded at relatively low temperatures (＜100 °C). Benzyl alcohol, benzaldehyde, benzoic acid and maleic anhydride were the main intermediate products in toluene degradation process. This work reveals the value of bimetallic MOFs derived Co-Mn oxides for toluene oxidation and presents a novel avenue for designing mixed metal oxide catalysts with potential applications in VOCs catalytic oxidation.

Methane Combustion Kinetics over Palladium-Based Catalysts: Review and Modelling Guidelines

Fugitive methane emissions account for a significant proportion of greenhouse gas emissions, and their elimination by catalytic combustion is a relatively easy way to reduce global warming. New and novel reactor designs are being considered for this purpose, but their correct and efficient design requires kinetic rate expressions. This paper provides a comprehensive review of the current state of the art regarding kinetic models for precious metal catalysts used for the catalytic combustion of lean methane mixtures. The primary emphasis is on relatively low-temperature operation at atmospheric pressure, conditions that are prevalent in the catalytic destruction of low concentrations of methane in emission streams. In addition to a comprehensive literature search, we illustrate a detailed example of the methodology required to determine an appropriate kinetic model and the constants therein. From the wide body of literature, it is seen that the development of a kinetic model is not necessarily a trivial matter, and it is difficult to generalize. The model, especially the dependence on the water concentration, is a function of not only the active ingredients but also the nature of the support. Kinetic modelling is performed for six catalysts, one commercial and five that were manufactured in our laboratory, for illustration purposes.

Analysis of the geotechnological potential of heavy oil/bitumen production based on the improved method of well hydraulic production

The work provides an analysis of technologies for the intensification of heavy oil and bitumen production. A variant of its improvement based on the technology of borehole hydraulic production supplemented by the processes of dissolution with hydrocarbon solvents and catalytic aquathermolysis is proposed. The technology involves transfer of main operations of technological chain “extraction-preparation” to the productive layer (transfer of rock to composition of hydraulic mixture; viscosity reduction as a result of heating, dissolution with hydrocarbon solvents, destruction as a result of catalytic aquathermolysis; flotation of oil/bitumen droplets and gravitational separation of the rock). At the same time, in order to increase the efficiency of the technology and use of catalyst, it is proposed to implement the catalytic destruction of asphaltenes starting from mining and continuing after extraction to the surface in a technological installation. Moreover, the required volume of the solvent fraction (taking into account its irreversible losses) is expected to be obtained directly at the deposit as a result of catalytic aquathermolysis and distillation at the final stage of preparation. The improvement will allow to ensure the maximum coefficient of extraction of hydrocarbons with simultaneous modernization to the level suitable for transportation by pipelines without additional preparation.

Unveiling the Function of Oxygen Vacancy on Facet-Dependent CeO2 for the Catalytic Destruction of Monochloromethane: Guidance for Industrial Catalyst Design.

Secondary pollution remains a critical challenge for the catalytic destruction of chlorinated volatile organic compounds (CVOCs). By employing experimental studies and theoretical calculations, we provide valuable insights into the catalytic behaviors exhibited by ceria rods, cubes, and octahedra for monochloromethane (MCM) destruction, shedding light on the elementary reactions over facet-dependent CeO2. Our findings demonstrate that CeO2 nanorods with the (110) facet exhibit the best performance in MCM destruction, and the role of vacancies is mainly to form a longer distance (4.63 Å) of frustrated Lewis pairs (FLPs) compared to the stoichiometric surface, thereby enhancing the activation of MCM molecules. Subsequent molecular orbital analysis showed that the adsorption of MCM mainly transferred electrons from the 3σ and 4π* orbitals to the Ce 4f orbitals, and the activation was mainly caused by weakening of the 3σ bonding orbitals. Furthermore, isotopic experiments and theoretical calculations demonstrated that the hydrogen chloride generated is mainly derived from methyl in MCM rather than from water, and the primary function of water is to form excess saturated H on the surface, facilitating the desorption of generated hydrogen chloride.

Catalytic destruction of oxalate in the supernatant stream generated during plutonium reconversion process

Abstract Plutonium oxalate supernatant requires a treatment step for further recovery of the residual Pu. As the oxalate ion present in the solution poses problems during the recovery of Pu, it needs to be destroyed. In the present work, Mn2+ based catalytic destruction of oxalate ion was studied in detail, as it could minimize the generation of secondary radioactive waste compared to the conventional process. The effect of various parameters, namely concentrations of HNO3, catalyst, oxalic acid and effect of the metal ion has been studied. Moreover, the robustness of the catalytic destruction method along with the kinetics of oxalate destruction reaction has been investigated. The process was also demonstrated with Pu supernatant generated from CORAL at 1 L scale.

Synergistic roles of Ru, CeO2, and HZSM-5 in a ternary-active center catalyst for catalytic destruction of dichloromethane

Developing well-qualified industrial catalysts with excellent oxidation ability, selectivity, and resistance is still a challenge for chloroalkane destruction. Herein, we optimized the composition of multi-component catalysts with diverse active sites to adjust their acidic and redox properties for reasonable catalytic performance. The synergy of redox center Ru, activation center CeO2, and acid center HZSM-5 endowed the ternary catalyst Ru/CeO2/HZSM-5 with superior low-temperature activity (30 ∼ 60 °C lower for 50 % conversion), promoted stability and chlorine tolerance (100 % conversion for at least 30 h), and less toxic by-products for dichloromethane (DCM) destruction compared with the binary ones, promising for industrial application under tough conditions (e.g., thermal shock, HCl, H2O). The strong interaction of Ru and CeO2 enhanced the redox property of Ru/CeO2/HZSM-5 and thus promoted the deep oxidation of DCM and intermediates, thereby generating more CO2 and less dechlorinated by-products (e.g., CH3Cl). The synergistic effects of Ru, CeO2, and HZSM-5 facilitated chlorine removal and suppressed the generation of polychlorinated by-products (e.g., CHCl3) over the Ru/CeO2/HZSM-5 catalyst by improving redox capacity and inhibiting reactivity of chlorine. Notably, the introduction of CeO2 weakened the hydrophilicity of Ru and HZSM-5, improving the water resistance of the catalyst. The corresponding monolithic catalyst could achieve complete oxidation of DCM at 400 °C with the total concentration of dioxins measured at 0.026 ng I-TEQ kg−1 after continuous operation at 250 °C for 30 h.

Low-temperature catalytic oxidation of PCDD/Fs over MnCeCoOx/PPS catalytic filter.

Catalytic destruction of nitrogen oxides (NOx) combined with dust removal technique has attracted much attention, yet the application in the solid waste incineration air pollution control process is still lacking due to the complex flue gas atmosphere. In this work, the Mn-Ce-Co-Ox catalyst-coated polyphenylene sulfide (PPS) filter fiber with efficient dust removal and low-temperature polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) destruction has been prepared with a redox-precipitation method. The catalyst was uniformly grown around the PPS fiber with appropriate catalyst loading. The effects of several key operating parameters (e.g., reaction temperature, catalyst loading amount, and filtration velocity) on the catalytic efficiency were comprehensively investigated. The results show that the Mn-Ce-Co-Ox/PPS has a decomposition yield of 78.0% in PCDD/Fs and 96% in nitric oxide (NO) conversion at 200 °C. The poisoned catalytic filter exhibits a removal efficiency of 88.6% for PCDD/Fs. In addition, the catalytic filter can completely reject particles smaller than 1.0 μm with a low filtration resistance. Therefore, this efficient and energy-conserving catalytic filter shows promising applications in flue gas pollution treatments.

Low-Temperature Propane Activation and Mineralization over a Co3O4 Sub-nanometer Porous Sheet: Atomic-Level Insights.

Light alkanes make up a class of widespread volatile organic compounds (VOCs), bringing great environmental hazards and health concerns. However, the low-temperature catalytic destruction of light alkanes is still a great challenge to settle due to their high reaction inertness and weak polarity. Herein, a Co3O4 sub-nanometer porous sheet (Co3O4-SPS) was fabricated and comprehensively compared with its bulk counterparts in the catalytic oxidation of C3H8. Results demonstrated that abundant low-coordinated Co atoms on the Co3O4-SPS surface boost the activation of adsorbed oxygen and enhance the catalytic activity. Moreover, Co3O4-SPS has better surface metal properties, which is beneficial to electron transfer between the catalyst surface and the reactant molecules, promoting the interaction between C3H8 molecules and dissociated O atoms and facilitating the activation of C-H bonds. Due to these, Co3O4-SPS harvests a prominent performance for C3H8 destruction, 100% of which decomposed at 165 °C (apparent activation energy of 49.4 kJ mol-1), much better than the bulk Co3O4 (450 °C and 126.9 kJ mol-1) and typical noble metal catalysts. Moreover, Co3O4-SPS also has excellent thermal stability and water resistance. This study deepens the atomic-level insights into the catalytic capacity of Co3O4-SPS in light alkane purification and provides references for designing efficacious catalysts for thermocatalytic oxidation reactions.

Implications of Snowpack Reactive Bromine Production for Arctic Ice Core Bromine Preservation

AbstractSnowpack emissions are recognized as an important source of gas‐phase reactive bromine in the Arctic and are necessary to explain ozone depletion events in spring caused by the catalytic destruction of ozone by halogen radicals. Quantifying bromine emissions from snowpack is essential for interpretation of ice‐core bromine. We present ice‐core bromine records since the pre‐industrial (1750 CE) from six Arctic locations and examine potential post‐depositional loss of snowpack bromine using a global chemical transport model. Trend analysis of the ice‐core records shows that only the high‐latitude coastal Akademii Nauk (AN) ice core from the Russian Arctic preserves significant trends since pre‐industrial times that are consistent with trends in sea ice extent and anthropogenic emissions from source regions. Model simulations suggest that recycling of reactive bromine on the snow skin layer (top 1 mm) results in 9–17% loss of deposited bromine across all six ice‐core locations. Reactive bromine production from below the snow skin layer and within the snow photic zone is potentially more important, but the magnitude of this source is uncertain. Model simulations suggest that the AN core is most likely to preserve an atmospheric signal compared to five Greenland ice cores due to its high latitude location combined with a relatively high snow accumulation rate. Understanding the sources and amount of photochemically reactive snow bromide in the snow photic zone throughout the sunlit period in the high Arctic is essential for interpreting ice‐core bromine, and warrants further lab studies and field observations at inland locations.

Efficient propane mineralization over unsaturated Pd cluster/CeO2 with prominent C-C cleavage capacity driven by inherent oxygen activation ability

Light alkanes extensively presented in industrial exhausts have led tremendous harm to the atmospheric environment and human health. However, the catalytic destruction of light alkanes generally operates at elevated temperatures and the consequent reaction by-products are inevitably produced. It is therefore of great significance to engineer catalysts with superior thermal stability, internal activity and selectivity. Herein, we developed a Pd cluster/CeO2 catalyst (Pdn/CeO2) by a scalable deposition precipitation strategy, which demonstrates unexpected activity and thermal stability in the presence of 5% H2O attributing to abundant unsaturated Pd metal sites and excellent oxygen dissociation performance. Pdn/CeO2 possesses a highly efficient C-C cleavage capability due to the persistent formation of a large number of oxygen vacancies. In comparison, the Pd1/CeO2 catalyst, which is preferential for C-H bond cleavage and inactive for C-C bond cracking, produces remarkable hazardous organic by-products such as propyne and propylene, inhibiting the continuous decomposition of propane. The present study sheds critical insights into engineering efficient and stable catalysts for light alkane destruction.

Catalytic oxidation degradation of volatile organic compounds (VOCs) – a review

Abstract Volatile organic compounds (VOCs) are considered one of the significant contributors to air pollution because they are toxic, difficult to remove, come from a wide range of sources, and can easily cause damage to the environment and human health. There is an urgent need for effective means to reduce their emissions. The current treatment technologies for VOCs include catalytic oxidation, adsorption, condensation, and recovery. Catalytic oxidation technology stands out among the others thanks to its high catalytic efficiency, low energy requirement, and lack of secondary pollution. The difficulty of this technology lies in the development of efficient catalysts. The research on loaded noble metal catalysts and non-noble metal oxide catalysts in this area over the past few years is briefly described in this work. Firstly, the catalytic destruction mechanism of organic volatile compounds is introduced. Secondly, the effects of structural modulation during catalytic oxidation, such as the adjustment of noble metal particle size and morphology, metal doping, and defect engineering, on the conformational relationships are discussed. Finally, the challenges faced by thermal catalytic oxidation for the degradation of VOCs are discussed, and the prospects for its development are presented.

High-entropy (CoCrFeMnNi)3O4 catalysts for propane catalytic destruction: Effect of the precipitation agent

Efficient catalytic destruction of light alkane with ultra-stable and highly symmetric structure is still an intractable issue. High entropy oxides (HEOs) with high chemical disorder and lattice distortion and superior stability have shown great potential in heterogeneous thermocatalysis. Herein, spinel-type HEOs are synthesized via a scalable co-precipitation method with different precipitants (NaOH, Na2CO3, and NaHCO3) and firstly adopted in catalytic destruction of propane. Results demonstrate that the HEO-NaOH possesses the best activity, achieving 90% of propane conversion at 325 °C with an apparent activation energy of 56 kJ mol−1. Compared with other two HEOs, the HEO-NaOH has larger quantities of surface oxygen vacancies and easily forms several reactive oxygen species (OOH−, O2−, and OH−, etc.), which significantly contribute to improve the catalytic performance. Moreover, the excellent water resistance of HEOs is verified due to their high conformational entropy and structural stability. Reaction mechanism reveals that OOH− and O2− are the key species in the oxidation of C3H8, which break C-H and C-C bonds in sequence, and are then converted to oxygenated compounds via oxygen oxidation before the final mineralization. The present work provides new insights into the fabrication of efficient catalysts for light alkane destruction as well as other thermocatalytic applications.

Green/sustainable strategy for the enhanced thermal destruction of abandoned, lost, discarded fishing gears (ALDFGs)

One of the most prevalent wastes in the ocean is abandoned, lost, and discarded fishing gears (ALDFGs), which poses a potential mortality risk to all marine creatures. Considering the complex compositional nature and non-biodegradability, the thermal destruction of ALDFGs could offer a strategic measure to abate all hazardous potentials triggered by ALDFGs. More specifically, it is of paramount significance to completely break down ALDFGs into the smallest molecules such as syngas (H2 and CO). Also, the conversion of ALDFGs into the smallest molecular units offer an innovative means for neutralizing toxic chemicals (that are inevitably generated from thermochemical process) given that toxicity is proportional to the degree of aromaticity/substitution of heteroatoms (S, N, Cl, etc.). To enhance the overall thermal destruction efficiency, carbon dioxide (CO2) was used as a raw material. CO2 was employed as the renewable resource for carbon and oxygen to enhance syngas formation. In detail, this study experimentally proved the mechanistic contribution of CO2 to shifting carbon in wax-like/liquid hydrocarbons (HCs) into CO. The formation of CO from catalytic thermal destruction under CO2 condition was 64 times more than from thermal destruction without catalyst under CO2. Before the thermal destruction, the plastic types of ALDFGs (fishing rope (PP/PE), line (nylon 6), and net (PE)) were determined. Also, FT-IR analysis revealed that all plastics components in ALDFGs were partially oxidized.

Catalytic oxidation of Benzene with manganese oxide supported on Cordierite

Volatile organic compounds (VOCs) are one of the principal causes of air pollution, posing a grave danger to the environment and human health due to their toxicity. In the presence of heat or light, catalytic oxidation has been recognized as a viable and efficient approach for VOCs remediation. Manganese-based oxides are one of the most environmentally benign and cost-effective choices for the catalytic destruction of volatile organic compounds in thermocatalysis. That is the reason why this article focused on catalytic oxidation to control benzene (a VOCs component). The wet impregnation process was used to produce manganese oxide supported on cordierites. Scanning electron microscopy (SEM), energy dispersive spectrometer mapping (EDS mapping), X-ray diffraction (XRD), and Hydrogen Temperature-programmed reduction (TPR-H2) were used to characterize the catalysts. When using the TCD-FID detector, catalytic activity measurements were done on a micro-flow reactor system coupled online to GC. The results showed that MnO2-Cor potential catalyst for completely oxidizing benzene with a 100% benzene conversion temperature of 350 C to CO2 and H2O. This catalyst provides high thermal stability and good reusability due to being carried on cordierite.

Characteristics of catalytic destruction of dichloromethane and ethyl acetate mixture over HxPO4-RuOx/CeO2 catalyst

Catalytic destruction is an ascendant technology for the abatement of volatile organic compounds (VOCs) originating from solvent-based industrial processes. The varied composition tends to influence each VOC's catalytic behavior in the reaction mixture. We investigated the catalytic destruction of multi-component VOCs including dichloromethane (DCM) and ethyl acetate (EA), as representatives from pharmaceutical waste gases, over co-supported HxPO4-RuOx/CeO2 catalyst. A mutual inhibitory effect relating to concentrations because of competitive adsorption was verified in the binary VOCs oxidation and EA posed a more negative effect on DCM oxidation owing to EA's superior adsorption capacity. Preferential adsorption of EA on acidic sites (HxPO4/CeO2) promoted DCM activation on basic sites (O2−) and the dominating EA oxidation blocked DCM's access to oxidation centers (RuOx/CeO2), resulting in boosted monochloromethane yield and increased chlorine deposition for DCM oxidation. The impaired redox ability of Ru species owing to chlorine deposition in turn jeopardized deep oxidation of EA and its by-products, leading to increased gaseous by-products such as acetic acid originating from EA pyrolysis. Notably, DCM at low concentration slightly promoted EA conversion at low temperatures with or without water, consistent with the enhanced EA adsorption in co-adsorption analyses. This was mainly due to that DCM impeded the shielding effect of hydrolysate deposition from rapid EA hydrolysis depending on the decreased acidity. Moreover, water benefited EA hydrolysis but decreased CO2 selectivity while the generated water derived from EA was likely to affect DCM transformation. This work may provide theoretical guidance for the promotion of applied catalysts toward industrial applications.

An experimental investigation of particulate emission characteristics of catalytic diesel particulate filters during passive regeneration

The catalytic diesel particulate filter (CDPF) can effectively reduce diesel particulate emissions, but its outlet particulate emissions increase significantly during active and passive regeneration. Understanding the particle emission characteristics and oxidation mechanism during CDPF regeneration is a prerequisite for seeking improvement measures and achieving near-zero emissions from diesel engines. This study focused on the particle emission characteristics during passive regeneration not previously detailed in the engine literature dedicated to catalytic diesel particulate filters. The commercial carbon black (Printex-U, PU) was utilized to replace diesel soot and loaded onto the CDPF substrate here. Experimental tests were conducted to investigate the effect of regeneration temperature and soot load on the CDPF response to exhaust particles during passive regeneration. The results showed that the diesel oxidation catalyst (DOC) reduced the particle number (PN) upstream of the CDPF device. In addition, the regeneration temperature and soot load altered the ratio of penetrating particles (PP), secondary particles (SP), and blown-out particles (BP), resulting in a complex particle emission profile in terms of particle concentration and size at the CDPF outlet. Moreover, the higher regeneration temperature enhanced the oxidation of the particulate matter and raised the particle number, while increasing the particle load enhanced the capture effect of incoming particles but also led to enhanced catalytic oxidation and destruction of the microstructure of the particle layer, thus increasing the discharged particle emissions.

The future ozone trends in changing climate simulated with SOCOLv4

Abstract. This study evaluates the future evolution of atmospheric ozone simulated with the Earth system model (ESM) SOCOLv4. Simulations have been performed based on two potential shared socioeconomic pathways (SSPs): the middle-of-the-road (SSP2-4.5) and fossil-fueled (SSP5-8.5) scenarios. The future changes in ozone, as well as in chemical drivers (NOx and CO) and temperature, were estimated between 2015 and 2099 and for several intermediate subperiods (i.e., 2015–2039, 2040–2069, and 2070–2099) via dynamic linear modeling. In both scenarios, the model projects a decline in tropospheric ozone in the future that starts in the 2030s in SSP2-4.5 and after the 2060s in SSP5-8.5 due to a decrease in concentrations of NOx and CO. The results also suggest a very likely ozone increase in the mesosphere and the upper and middle stratosphere, as well as in the lower stratosphere at high latitudes. Under SSP5-8.5, the ozone increase in the stratosphere is higher because of stronger cooling (>1 K per decade) induced by greenhouse gases (GHGs), which slows the catalytic ozone destruction cycles. In contrast, in the tropical lower stratosphere, ozone concentrations decrease in both experiments and increase over the middle and high latitudes of both hemispheres due to the speeding up of the Brewer–Dobson circulation, which is stronger in SSP5-8.5. No evidence was found of a decline in ozone levels in the lower stratosphere at mid-latitudes. In both future scenarios, the total column ozone is expected to be distinctly higher than present in middle to high latitudes and might be lower in the tropics, which causes a decrease in the mid-latitudes and an increase in the tropics in the surface level of ultraviolet radiation. The results of SOCOLv4 suggest that the stratospheric-ozone evolution throughout the 21st century is strongly governed not only by a decline in halogen concentration but also by future GHG forcing. In addition, the tropospheric-ozone column changes, which are mainly due to the changes in anthropogenic emissions of ozone precursors, also have a strong impact on the total column. Therefore, even though the anthropogenic halogen-loading problem has been brought under control to date, the sign of future ozone column changes, globally and regionally, is still unclear and largely depends on diverse future human activities. The results of this work are, thus, relevant for developing future strategies for socioeconomic pathways.