The sustainable conversion of carbon dioxide into bio-based cyclic carbonates offers a promising route to green chemicals and polymers. We report the efficient synthesis of limonene-based cyclic carbonates via cycloaddition of CO2 to limonene diepoxide (LDO) under solvent-free conditions using a series of covalently grafted supported ionic liquid catalysts (SILC). Key synthesis parameters, such as ionic liquid structure, support type, grafting time, acid pretreatment, and the addition of Lewis acid sites, were systematically varied and their effect on the catalytic activity was assessed. Catalyst morphology and performance were correlated through comprehensive characterization via solid state 13C CP-MAS and 29Si NMR, TGA, Nitrogen physisorption, ion chromatography and CHNS analysis. Among the prepared systems, 4-pyrrolidino-pyridinium chloride (4PPCl) grafted on acidtreated SiO2 for 48 h showed the best performance, achieving 95 % LDO conversion with full selectivity towards limonene carbonates. Based on kinetic experiments at different temperatures the apparent activation energy was estimated to 61 kJ mol-1 . Catalyst stability tests confirmed negligible ionic liquid leaching. Surface blockage by viscous residues was responsible for partial deactivation, which was mitigated by cleaning the catalyst by Soxhlet extraction. The work demonstrated how rational catalyst design, combining tailored ionic liquids with optimized supports and grafting time, can promote efficient valorization of carbon dioxide into biobased cyclic carbonates.

Abstract In this work, limonene-based non-isocyanate polyurethane (NIPU) foams were synthesized for the first time. Highly pure limonene dicarbonate (LDC) was obtained via CO2 cycloaddition to limonene diepoxide. The sustainability of the precursor synthesis was quantitatively assessed considering all reaction and post-reaction chemicals, yielding a complete E-factor (cEF) of 8.3. LDC was subsequently blended with carbonated soybean oil (CSBO) to tailor the final foam properties. The aminolysis kinetics of LDC and CSBO with bio-based 1,4-butanediamine was systematically investigated to identify optimal reaction conditions. Different formulations were prepared by varying the type and concentration of blowing agents, i.e., sodium bicarbonate, ammonium acetate, and water. Rigid NIPU foams of bio-based content ≥96% were successfully obtained and characterized in terms of physical, thermal, morphological, and mechanical properties. Among the blowing agents tested, sodium bicarbonate at 3 wt % produced the most favorable foam morphology (average cell size of 275.6 μm) and mechanical performance (elastic modulus of 2.3 kPa), as it thermally decomposes into sodium carbonate, acting as a reinforcing and nucleating filler. Overall, this study unlocks the possibility of using a terpene as a bio-based source for NIPU foams by establishing a new synthesis protocol.

Spent lithium-ion batteries represent a growing environmental challenge, yet their transition-metal-rich cathodes remain largely underutilized as functional materials. We report a direct upcycling strategy in which LiCoO2 cathodes recovered from end-of-life smartphones are transformed into efficient heterogeneous catalysts via a single-step oxidative calcination (600 °C, 6 h, air). The resulting material retains a predominantly layered Li1-xCoO2 structure with a minor spinel-like phase formed during treatment. This reconstructed fraction significantly enhances cobalt reducibility, introducing a low-temperature reduction feature absent in the untreated precursor. Under 20 bar H2 at 180 °C, the catalyst selectively converts furfural to furfuryl alcohol at short reaction times, while prolonged reaction promotes further hydrogenation to tetrahydrofurfuryl alcohol, enabling tunable selectivity. Compared with the untreated precursor and commercial references, the calcined material shows markedly improved catalytic activity. Computational simulations reveal that the spinel-like phase provides the most favorable adsorption and activation of furfural, identifying it as the dominant catalytic motif. Catalyst deactivation is reversible, and activity is largely restored by a simple recalcination step. These results establish spent LiCoO2 cathodes as readily accessible cobalt-based catalysts for upgrading biomass-derived platform molecules, providing a circular route that couples battery-waste valorization with sustainable chemical manufacturing.

Combined direct synthesis of hydrogen peroxide (DSHP) and epoxidation of propene to propylene oxide with hydrogen peroxide (HPPO) was carried out first time in a continuous laboratory-scale trickle bed reactor operating under mild conditions of 8 bar and 10 degrees C. The reaction was performed with bimetallic gold-palladium catalysts supported on titanium silicalite 1 (TS-1). Three series of catalysts were synthesized from two different lots of TS-1 and different calcination heating rates. The catalysts were extensively examined using XRD, SEMEDS, TEM-SAED, STEM-EDS, ICP-OES, XPS, UV-vis DRS, nitrogen-physisorption and ammonia-TPD. The metal-modification of TS-1 containing anatase impurities was shown first time, where the preferential deposition site for the bimetallic nanoparticles was on the minor anatase phase, found in different amounts in commercial TS-1 materials. In the first catalyst series, a higher anatase content was found, which led to a decrease of the AuPd nanoparticle size compared to the second and third series. Increasing the heating rate in calcination resulted in an additional reduction of the AuPd nanoparticle size. The propylene oxide selectivity was 55.7 % using catalysts of the third series, while the propylene oxide production rate was 0.17 mol & sdot;kgcat propene conversion. The use of a palladium-poor alloy was found to be crucial for this reaction system to limit the hydrogenation of hydrogen peroxide and propene. The catalyst activity was investigated in the separate processes of DSHP and epoxidation to get a deeper insight into the reaction mechanism. In the switch experiments, DSHP followed by the combined reaction of DSHP and HPPO, the competing side reactions, hydrogenation of propene and hydrogen peroxide were confirmed. In another experiment, the dismutation of hydrogen peroxide was disproved.

Epoxidized vegetable oils are used as green intermediates in organic synthesis as well as biolubricants and plasticizers. Epoxidation of double bonds in a commercial vegetable oil mixture was carried out in a laboratoryscale semibatch reactor, which was operated at 25-30 degrees C and at atmospheric pressure. Potassium persulphate was used as the oxidation agent and potassium hydroxide was added to the reaction mixture to maintain the pH constant. An extensive experimental optimization of the reaction conditions (oxidant-to-double bond ratio and oxidant feed rate) was carried out, revealing that more than 95% of the double bonds could be epoxidized in the best cases. The experiments provided a large set of kinetic data which were modelled mathematically. Mathematical expressions for the epoxidation rate were derived, based on plausible reaction mechanisms and on the principle of quasi-stationarity for the reaction intermediates appearing in the molecular mechanism of the double bond epoxidation. The kinetic parameters in the mathematical model, a set of ordinary differential equations for the components in the semibatch reactor, were determined by non-linear regression analysis. A comparison of the model predictions with experimental data revealed that the model described the epoxidation kinetics of vegetable oils in the isothermal and isobaric semibatch reactor very well.

The renewed interest in hydrogen peroxide-based space propulsion systems has highlighted the persistent issue of catalyst degradation during long-term operation. Although several studies have investigated the underlying causes of this phenomenon, effective regeneration techniques capable of restoring catalytic activity have not yet been clearly demonstrated. This study investigates the mechanisms responsible for performance degradation and proposes a viable regeneration strategy for palladium-based catalysts. Experimental analyses were conducted on a batch of commercial Al2O3/Pd pellets subjected to multiple firing cycles in a 10 N-class hybrid mini-thruster. Monitoring of the propulsive performance revealed a progressive decline in catalytic activity, ultimately preventing ignition of the hybrid rocket engine. To characterize the degradation mechanisms, the pellets were examined through visual inspection, static hydrogen peroxide decomposition tests, and Temperature Programmed Reduction (TPR) analysis. The results indicated significant surface oxidation of palladium, leading to reduced decomposition efficiency. A chemical regeneration procedure based on sodium borohydride (NaBH4) treatment was subsequently developed to restore catalytic performance. The regenerated pellets were tested under the same experimental conditions that had previously led to ignition failure. Their propulsive performance was then compared with both the degraded pellets and a new batch of equivalent catalysts. The results demonstrate that the regeneration process successfully restored the catalytic activity to levels comparable with the original state, enabling stable and efficient hybrid combustion. These findings confirm the role of surface oxidation in catalyst degradation and demonstrate that targeted chemical treatment can significantly extend catalyst lifetime. The proposed regeneration strategy offers a practical method to reduce costs of ground-based experimental campaigns and support the future deployment of hydrogen peroxide-based propulsion systems in space applications by providing insights into the mechanisms that can degrade the performance of palladium catalysts.

This study explores the feasibility of synthesizing trazodone in continuous mode using a tubular reactor and investigates the impact of ultrasound on phase-transfer-catalyzed (PTC) N-alkylation. A continuous flow apparatus was designed in which the 2-(3-chloropropyl)-1,2,4-triazolo[4,3-a]pyridin-3-(2H)-one (TAP), the trazodone precursor, was prepared. While attempts to directly convert the solid-liquid (S-L) batch synthesis from a reference study into continuous mode were unsuccessful, a novel liquid-liquid (L-L) approach was developed. The L-L reaction system comprised an aqueous phase containing TAP, potassium carbonate, and tetrabutylammonium bromide, while the organic phase included 1-bromo-3-chloropropane in ethyl acetate. The key reaction parameters, such as temperature, residence time, and concentration of different reaction components, were examined for their influence on TAP conversion, product yield, and selectivity. These reaction parameters were optimized under continuous flow conditions to achieve a high product yield. The activation energy and the apparent kinetic constant, assuming pseudo-first-order reaction kinetics, were estimated from the experimental data. Ultrasound irradiation positively impacted the reaction, improving substantially the yield of the continuous flow synthesis. The elementary reaction mechanisms for both S-L and L-L phase transfer-catalyzed processes were proposed.

Removal of pharmaceuticals from wastewater remains a major environmental challenge, requiring efficient and selective Advanced Oxidation Processes (AOPs). Catalytic and non-catalytic ozonation was investigated in a laboratory-scale reactor under optimized flow conditions (500-750 mL min-1, 98 % O2 feed). Ozonation kinetics of active pharmaceutical ingredient mixtures (APIs) consisting of ibuprofen (IBU), diclofenac (DCF), carbamazepine (CBZ), sulfadiazine (SDZ), and sulfamethoxazole (SFX) (40 mg L-1 each) - was investigated using iron-modified zeolite catalysts, Fe-H-Y and Fe-H-Beta, under semi-batch operations (0.5 g catalyst, 20 degrees C) in order to correlate degradation and mineralization efficiency with catalyst structure, acidity, and stability. Both catalysts significantly improved the ozone utilization compared to non-catalytic ozonation. Interestingly, Fe-H-Y accelerated initial degradation rate, while the use of Fe-H-Beta resulted in the highest level of mineralization. Adsorption-desorption analysis revealed that the molecular size and polarity controlled the interactions between the pharmaceutical and the catalyst: smaller polar compounds (SDZ, SFX) exhibited stronger adsorption on the catalyst, while bulkier molecules (DCF, IBU) were restricted to external surfaces. Post-reaction characterization confirmed that the Fe-H-Y retained more surface area and exhibited lower Fe leaching, while Fe-H-Beta showed significantly higher carbon deposition. Overall, Fe-H-Y combined rapid kinetics and structural stability, while Fe-H-Beta provided higher mineralization, at the expense of more extensive fouling. The study demonstrated that optimized ozonation conditions, coupled with tailored zeolite catalysts, markedly improve the oxidation efficiency and long-term performance in the oxidation of pharmaceuticals.

Novel continuous propylene oxide production via in-situ generated hydrogen peroxide under mild liquid phase conditions was optimized by tailoring gold-palladium on titanium silicalite 1 (TS-1) catalysts and reaction parameters. AuPd alloy nanoparticles were deposited on two commercial TS-1 supports, with and without anatase impurities. On anatase-free TS-1, highly dispersed AuPd nanoparticles (6-10 nm) were formed, whereas in anatase-containing TS-1, metal precursors preferentially deposited on anatase, yielding larger nanoparticles after calcining. Ammonium hydroxide and water, water-only washing, and no washing were applied after synthesis, with water-only washing yielding smallest nanoparticles. Prolonged urea-deposition synthesis promoted metal redispersion, confirmed by material sampling during synthesis, and improved catalyst stability. In the combined direct synthesis of hydrogen peroxide and hydrogen peroxide to propylene oxide process (HPPO), smaller AuPd nanoparticles enhanced propylene oxide production but decreased propylene oxide selectivity by formation of propane and ring-opening products. Au-richer alloys improved propylene oxide selectivity but decreased propylene oxide productivity, while monometallic gold was inactive in the reaction system. Higher metal loadings increased propylene oxide productivity only for gold-richer alloys. Reaction parameter optimization identified that higher temperature and reduced liquid flow rate favored hydrogen peroxide conversion and ring-opening products formation, while shifting from propene-rich to oxygen-rich feed suppressed propane formation.

In response to the growing need to reduce reliance on petrochemical feedstock and eliminate toxic isocyanates in polyurethane production, this study presents the synthesis of composite non-isocyanate polyurethane (NIPU) foams starting from a novel blend of bio-based cyclic carbonates. The resulting flexible foams are fully reprocessable and have a bio-based content ranging from 92% to 99%. They were prepared through a two-step procedure where aminolysis was first carried out between 1,4-butane diamine (BDA) and blends of carbonated soybean oil (CSBO) and bio-based butanediol bis-cyclic carbonate (BCC). A blowing reaction was induced via S-alkylation using a dithiol while diatomite was incorporated as a renewable nanoporous filler providing nucleating and reinforcing properties. The influence of the CSBO/BCC ratio on foam properties was systematically investigated through chemical, physical, thermal, and morphological analyses. A structure-property relationship was established using an adapted Gibson-Ashby model. The resulting foams exhibited open-cell morphology with uniform cell sizes (400-600 mu m) and apparent densities between 200 and 250 kg m-3. Notably, the foams were successfully re-shaped into flexible films via temperature-controlled compression molding, confirming their potential for recyclability and reuse. The stress-relaxation behavior of the re-processed NIPU presented a decreasing trend by increasing the relaxation time and was described by the Kohlrausch-Williams-Watts function. The activation energy was calculated according to the Arrhenius equation and was found to be 91 +/- 8 kJ mol-1 indicating a relatively strong temperature dependence of the relaxation mechanisms. This work unlocks a new design strategy for the sustainable synthesis of fully recyclable NIPU foams, opening up new directions in green polyurethane chemistry.

Photocatalytic activity, reaction kinetics, modeling, and thermodynamics of commercial TiO2-P25 and ZnO nanoparticles (NPs) for ibuprofen (IBU) photodegradation were investigated. Photodegradation experiments were performed in a batch reactor under UV irradiation. The photodegradation performances of TiO2-P25 and ZnO NPs were further studied and modeled under different operation conditions, by varying the reaction temperature, catalyst bulk density, and the initial concentration of the IBU solution. The descriptive kinetic models for the experimental data were tested, through the estimated kinetic parameters, together with the statistical information, revealing that the reaction rate in the case of TiO2-P25 is of first order while the ZnO NPs follow second-order kinetics with respect to IBU. The photodegradation mechanisms for both TiO2-P25 and ZnO NPs were determined to be Langmuir-Hinshelwood and Eley-Rideal, respectively. Thermodynamic parameters were assessed, particularly, changes in Gibbs free energy, enthalpy, and entropy indicating the efficient photodegradation performance of these NPs.

The conversion of CO2 into value-added cyclic carbonates via cycloaddition to bio-derived epoxides presents a sustainable approach for CO2 utilization. However, the production of cyclic carbonates from bio-sources such as epoxidized vegetable oils (EVOs) have significant challenges due to the low reactivity of CO2 and the steric hindrance of internal epoxides in these bulky substrates. Consequently, the majority of systems for CO2 fixation to bio-based epoxides rely on homogeneous catalysis. This study investigated the conversion of epoxidized methyl oleate, a model compound for EVOs, into its corresponding cyclic carbonate using heterogeneous 4-pyrrolidinopyridine-based catalysts. The influence of various catalytic parameters, such as the halide counter anions (Cl, Br, I) and incorporated metal Lewis acid centra, was explored within the catalyst. Among the halide counter anions, bromide exhibited a superior performance, achieving 65 % conversion and 59 % cyclic carbonate yield by the end of the experiment, while the effect of various metal centra was less pronounced, with an overall improvement in the cyclic carbonate yield of less than 10 % compared to the metal-free catalyst. A comprehensive study of reaction parameters, including the temperature (100-170 degrees C), the CO2 pressure (20-40 bar), and the catalyst loading (2.9-10.7 wt%), was conducted in a laboratory-scale autoclave reactor to elucidate the behavior of the reaction system.

Packed beds are among the most used reactors in many sectors of chemical industries. In this work, the aim was to develop a general dynamic heterogeneous multiscale model for continuous packed bed reactors, by using experimental data to improve the accuracy of mass transfer modelling. Arabinose oxidation to arabinoic acid with molecular oxygen was used as a case study. Experiments were performed in a continuous reactor system composed of a packed bed connected with a buffer tank for allowing recycling of the liquid phase and precise pH control. The packed bed was filled with laboratory prepared gold on alumina (3 %) catalyst extrudates. Various liquid flowrates were screened (150 mL/ min, 200 mL/min and 250 mL/min). The obtained experimental results were used to estimate more accurately the gas-liquid mass transfer coefficient, which was implemented in the model by using the gPROMS Model Builder. The effect of different liquid flowrates on the reactor performance was evaluated. The results showed that complete arabinose conversion can be obtained in all the cases. However, a high conversion was achieved faster in case of higher liquid flowrates (9.9 h for the 250 mL/min, 10.4 h for the 200 mL/min and 10.95 h for 150 mL/min), which agreed with our experimental discoveries: the reason is that the high flow rate suppresses the external mass transfer resistances at the gas-liquid interface and around the catalyst extrudates.

Since the discovery of titanium silicate-1 (TS-1) by Enichem several decades ago, the addition in small amounts of ammonia to the feed has been frequently mentioned in the patent literature as being key to improving the catalytic performance in epoxidations. The present study aims to investigate the molecular effect of this pro- motor. To achieve this, we addressed the mass transfer limitations of the reaction using shaped extrudates. Under the investigated conditions, the addition of 33 ppm of ammonia to the reactor feed increases the epoxide selectivity from 60 % to 100 %. However, the improvement in selectivity is accompanied by a decrease in activity as the concentration of the additive increases. The effect of ammonia was further explored through time-resolved IR experiments and DFT calculations, which reveals an interaction between ammonia and the titanium active sites, leading to the formation of more accessible pentacoordinate titanium active sites. This work highlights the importance of additives in industrial system studies, providing valuable insights for both industrial applications and academic research.

Design, fabrication, and evaluation of the performance of 3D-printed Pd/Al2O3catalysts for the low-temperature catalytic decomposition of hydrogen peroxide was investigated. Catalyst supports were manufactured using a digital light processing (DLP) 3D printing technique, followed by post-printing infiltration with colloidal boehmite to enhance the mechanical strength of the supports. Wet impregnation methods using PdCl2 and Pd (Ac)2as the palladium precursors were employed to deposit metal nanoparticles onto the structured alumina supports. For the most effective deposition route, various strategies, using either molecular hydrogen or sodium borohydride as the reducing agent, were applied to assess their influence on the catalytic activity. The decomposition experiments were carried out in a closed-loop batch reactor system. Apparent rate constants and deactivation coefficients were estimated using simplified batch and tank-in-series reactor models. Catalyst durability was further investigated with X-ray photoelectron spectroscopy (XPS) to assess the oxidation states of the palladium nanoparticle surface, and temperature-programmed reduction (TPR) to evaluate the reducibility of the palladium oxides. Structure-activity relationships were established by correlating kinetic parameters with hydrogen uptake data and average nanoparticle size obtained from transmission electron microscopy (TEM). The results demonstrated the critical impact of the precursor and the reduction methods on both the initial activity and the resistance against deactivation. This work provides a robust foundation for the further development of 3D-printed Pd/Al2O3 catalysts, offering a promising pathway to improve the efficiency of green propulsion systems for small satellites utilizing hydrogen peroxide as a propellant.

Methane obtained through the Sabatier reaction offers a promising pathway toward achieving carbon neutrality by facilitating efficient energy and hydrogen storage and balancing. The high purity required for methane in the gas grid and combustion engines presents a significant challenge, as the gas purification process is both energyintensive and costly. Ideally, a pure methane stream should be produced directly during the reaction between carbon dioxide and hydrogen, eliminating the need for separation steps. Hydrogen gas produced from renewable sources or from the surplus of energy production and carbon dioxide collected from the flue gases of industries can be reacted together to obtain a carbon neutral fuel. Due to the thermodynamic limitations of carbon dioxide methanation, producing a pure stream of methane in a single process step with conventional technology employing commercial nickel catalysts is unfeasible. However, the removal of one of the products, water from the reactive catalyst sites, can shift the equilibrium towards methane. A bifunctional material that combines water adsorption sites and catalytic synthesis sites in close proximity presents a promising solution compared to traditional mechanical mixtures of catalyst and sorbent. While the research on this approach is still limited, it has been demonstrated to effectively yield high-purity methane. This article provides a focused and comprehensive review of the existing literature, evaluating both the potential and challenges associated with the sorption-enhanced methodology. The findings suggest that sorptionenhanced methanation holds significant promise for large-scale production, with further research needed to address the remaining challenges.

Design, fabrication, and evaluation of the performance of 3D-printed Pd/Al₂O₃ catalysts for the low-temperature catalytic decomposition of hydrogen peroxide was investigated. Catalyst supports were manufactured using a digital light processing (DLP) 3D printing technique, followed by post-printing infiltration with colloidal boehmite to enhance the mechanical strength of the supports. Wet impregnation methods using PdCl₂ and Pd(Ac)₂ as the palladium precursors were employed to deposit metal nanoparticles onto the structured alumina supports. For the most effective deposition route, various strategies, using either molecular hydrogen or sodium borohydride as the reducing agent, were applied to assess their influence on the catalytic activity. The decomposition experiments were carried out in a closed-loop batch reactor system. Apparent rate constants and deactivation coefficients were estimated using simplified batch and tank-in-series reactor models. Catalyst durability was further investigated with X-ray photoelectron spectroscopy (XPS) to assess the oxidation states of the palladium nanoparticle surface, and temperature-programmed reduction (TPR) to evaluate the reducibility of the palladium oxides. Structure–activity relationships were established by correlating kinetic parameters with hydrogen uptake data and average nanoparticle size obtained from transmission electron microscopy (TEM). The results demonstrated the critical impact of the precursor and the reduction methods on both the initial activity and the resistance against deactivation. This work provides a robust foundation for the further development of 3D-printed Pd/Al₂O₃ catalysts, offering a promising pathway to improve the efficiency of green propulsion systems for small satellites utilizing hydrogen peroxide as a propellant.

Solid activated metal foam catalysts represent a promising alternative for the continuous production of valuable sugar alcohols. Traditionally, sugar alcohols are produced industrially in batch mode using finely dispersed Raney-type nickel catalysts. In this study, novel solid foam Raney-type Ni catalysts (activated metal foam catalysts) were used for the hydrogenation of xylose to xylitol in both batch and continuous operation. Two types of catalysts were investigated: Raney-type Ni foam (Metalyst (R) MC 911 by Evonik Operations GmbH, Ev-F-Ni) and Raney-type Ni foam promoted with molybdenum (Metalyst (R) MC 981 by Evonik Operations GmbH, Ev-F-NiMo). Catalyst deactivation was primarily attributed to the accumulation of strongly adsorbed organic species on the active sites and to Ni and Al leaching, which reduced the availability of catalytically active sites. Ev-F-NiMo demonstrated a superior stability and activity compared to Ev-F-Ni, attributed to electronic interactions between Mo and Ni, which stabilize Ni in a lower oxidation state and reduce metal leaching under reaction conditions. In continuous operation, the catalysts exhibited reduced deactivation, likely due to enhanced desorption of poisons under the continuous flow of fresh feed. Although the exposure to xylonic acid, a potential poison forming on the catalyst surface, temporarily reduced the xylitol yield in continuous mode, the Ev-F-NiMo catalyst demonstrated good resilience, recovering its activity after the removal of the poisoning species. These results highlight the very attractive technical solution for the continuous production of sugar alcohols from sugar monomers, utilizing promoted Raney-type Ni catalyst that is highly active, selective and cost-effective.

This review includes the key steps in the synthesis of NIPUs. The key aspects in the synthesis, characterization, and functionalization of NIPUs are analyzed in detail, along with giving insights into the recently published LCA analyses.

Ferric sulfate is an efficient coagulant in water treatment. Ferric sulfate is produced via oxidation of ferrous sulfate. The reaction proceeds spontaneously in the absence of an added catalyst, but the rate can be enhanced by solid catalysts, such as active carbon and metal-doped active carbon. The reaction environment is a complex gas-liquid (GL) or a gas-liquid-solid (GLS) system, with a strong interaction of gas solubility, interfacial mass transfer and kinetic effects. Because of the large volumes in the water treatment, selection of continuous reactor technology is an evident option. The aim of this work was to perform model simulations for continuous stirred tank reactors and tubular reactors by using a multiscale approach, from the kinetics of catalytic surface reactions to transport phenomena and flow pattern. The kinetic equations for non-catalytic and catalytic reactions were extracted from previous studies, as well as the Henry's constant for oxygen solubility. Mass balance equations permitted to obtain the reactor models which were solved numerically. The results showed that the non-catalytic reaction is non-negligible but not sufficient for effective oxidation. Oxygen can be introduced in excess to compensate for the oxygen remaining in gas phase during the process. The tubular reactor concept and the series of two continuous stirred tank reactors (both catalytic or one non-catalytic and one catalytic) showed very satisfactory results, enabling a high conversion of ferrous sulfate to ferric sulfate.