Elucidating an unrecognized iron leaching mechanism via sequential reduction-oxidation of passivation layer on stainless-steel cathodes for electro-Fenton process.

Continuous catalytic epoxidation of biodiesel for sustainable production of bio-based plasticizers using molecular oxygen

Although single-atom catalysts (SACs) deliver the merits of homogeneous and heterogeneous catalysts, challenges like metal leaching and poor mass transport limit their practical performance. Herein, we report an atomically dispersed Fe single-atom decorated on hierarchical porous carbon (hierarchical porous C) support, featuring an ultrahigh active site density (1.21 × 10 20 sites g −1 ) and mixed micro/ meso /macro-pores to overcome mass transfer limitations. Moreover, the abundant carbon defects around Fe sites synergistically enhance oxygen reduction reaction (ORR) process. Density functional theory (DFT) calculations reveal that defect-mediated FeN 4 precisely modulates the Fe d-band center via charge redistribution, effectively weakening OH* adsorption and accelerating the ORR kinetics. Thus, Fe-N-CPs@CB exhibits exceptional alkaline ORR performance than Pt/C. Fe-N-CPs@CB enables aqueous Zn-air battery (A-ZAB) with a large open-circuit voltage (OCV) of 1.51 V and remarkable cycling stability for over 800 h with high round-trip efficiency during the whole cycling process. Quasi-solid-state Zn-air battery (QSS-ZAB) enables a large peak power density of 230.5 mW cm −2 and excellent reversibility for over 106 h at 0.5, 1.0, and 2.0 mA cm −2 , significantly outperforming Pt/C. Additionally, oxygen depolarized cathodes (ODCs)-based two-electrode chlor-alkali electrolyzer using Fe-N-CPs@CB achieves a significantly lower cell voltage of 1.60 V at 300 mA cm −2 than Pt/C counterpart (1.69 V). Notably, it also shows excellent durability for over 100 h. This work provides a rational design principle for high-performance ORR catalysts by synergistically engineering atomic sites and hierarchical porosity for enhanced activity, stability, and mass transport. • Hierarchical porous Fe-N-CPs@CB has ultrahigh single atom active site density (1.21 × 10 20 g −1 ). • Vacancy-modulated Fe N 4 active site enhances ORR kinetics. • Fe-N-CPs@CB-ZAB delivers large open-circuit voltage and peak power density. • Fe-N-CPs@CB-ZAB exhibits exceptional reversibility. • Fe-N-CPs@CB||RuO 2 chlor-alkali electrolyzer shows excellent durability over 100 h at 300 mA cm −2 .

Review of the selective oxidation of toluene into benzaldehyde

The increasing global demand for sustainable aviation fuels has driven extensive research on developing efficient heterogeneous catalysts. This study investigates the effect of different surface functionalization methods of mesoporous SBA-15 on its catalytic activity for the production of a C16 precursor of bio-aviation fuel. The SBA-15 surfaces were modified by two acid functionalization routes, namely sulfonation and sulfation, to enhance its surface acidity and catalytic activity. Sulfonation was carried out using 3-mercaptopropyltrimethoxysilane (MPTMS) followed by oxidation to obtain the SO3H–SBA-15 catalyst containing sulfonic acid groups (–SO3H), while sulfation using ammonium sulfate as a precursor produced the SO4–SBA-15 catalyst containing sulfate groups (SO42-). Both catalysts were characterized using NH3-TPD and acid-base titration to quantify the total acidity. The catalytic performance was evaluated through hydroxyalkylation-alkylation (HAA) reaction between 2-methylfuran (2-MF) and methyl isobutyl ketone (MIBK) to synthesize a C16 bio-aviation fuel precursor, 5,5′-(4-methylpentane-2,2-diyl) bis(2-methylfuran) abbreviated as MPM. The results revealed that both modification methods effectively increased the total acid of SBA-15. However, the sulfated SBA-15 catalyst exhibited superior catalytic activity and stronger acid strength than the sulfonated one due to formation of more acid sites on its surface. Therefore, the sulfation route was identified as a more effective strategy for developing highly active solid acid catalysts. This research demonstrates the superior properties of sulfated mesoporous SBA-15 as a promising and sustainable heterogenous catalyst for converting biomass-derived platform chemicals into advanced C16 bio-aviation fuel precursors.

Ion-paired porous reactors for converting diluted CO2 into S-formylated products.

WS2-modified schwertmannite for highly efficient dye wastewater degradation via enhanced Fe cycle in heterogeneous Fenton-like catalysis.

This study demonstrates a simple and scalable synthesis of α-FeOOH (goethite) intercalated Ti 3 C 2 T x MXene through TMAOH treatment, targeting efficient degradation of emerging micropollutants in wastewater via an advanced oxidation process (AOP). Such a α-FeOOH-intercalated MXene stabilizes heterogeneous Fenton-based reactions which usually suffer from decreased efficiency over time due to Fe leaching, thus highlighting the novelty of the work. The successful integration of goethite particles in the MXene interlayer space was evidenced by X-ray diffraction (XRD), Fourier-transform infrared spectrometer (FTIR) and Transmission Electron Microscopy (TEM) analysis. X-ray photoelectron analysis (XPS) revealed notable surface oxidation along with minor TiF x and TiO 2-x F x impurities formed via TMAOH treatment. Increased concentration of surface functional groups along with enhanced BET area (71.2 m 2 g -1 ) and porosity after TMAOH treatment enabled complete degradation of caffeine in ⁓ 90 minutes, by activation of peroxymonosulfate (PMS) under UVA light. Scavenging experiments, electron paramagnetic resonance (EPR) and XPS analysis indicated the degradation mechanism driven by Fenton-based reactions, electron transfer and interfacial surface charge transfers, with hydroxyl ( • OH) and sulfate ( SO 4 • − ) radicals identified as predominant reactive oxygen species (ROS). The assessment of the α-FeOOH-intercalated MXene as stable Fenton catalyst was confirmed with minimal iron leaching (3.07 wt. %) during catalytic reactions and robust reusability over ten cycles, thus being more efficient and sustainable than conventional Fenton-based catalysts. Post-reaction XRD,FTIR and TEM analyses further confirmed excellent structural stability of the new catalyst. These findings establish α-FeOOH-intercalated Ti 3 C 2 T x MXene as a promising and durable catalyst for heterogeneous Fenton-based reactions applied to wastewaters treatment. Visible-light PMS activation by α-FeOOH/Ti 3 C 2 T x MXene for efficient caffeine elimination.

Valorization of Vicia faba L. peel ash as a novel heterogeneous green catalyst for biodiesel production from waste cooking oil

• Novel 1,2,4-triazole sulfonic acid porphyrin photocatalyst synthesized. • TBSAFPc displayed a 97% degradation efficiency of Rhodamine B. • Optimized parameters revealed: 10 ppm, 0.2 g/L TBSAFPc, pH 5 in 180 min. • TOC of the degraded RhB sample was 82.92% attained. • The optimized parameter effectively degraded 250mL RhB with 84.26% efficiency. The increasing discharge of synthetic dyes into aquatic systems poses serious environmental concern due to their toxicity and resistance to conventional treatment methods. In this context, the development of efficient, metal-free, and sustainable photocatalysts is highly desirable. Herein, a novel 1,2,4-triazole-based sulfonic acid functionalized porphyrin (TBSAFPc) was successfully synthesized via the reaction of triazole ionic liquid and pyrrole under reflux conditions in the presence of glacial acetic acid. The prepared TBSAFPc was confirmed by 1 H NMR, 13 C NMR, PXRD, FT-IR, SEM techniques. The Hammett acidity, and energy band gap (DRS) were determined by UV-Visible Spectrophotometer while surface area was studied by BET method. The photocatalytic performance of TBSAFPc was investigated for the degradation of Rhodamine B (RhB) under irradiation with a low-power 5 W LED light source in a homemade photo-chamber under ambient conditions. The catalyst exhibited excellent photodegradation efficiency of 97 % for a 10 ppm RhB solution without the use of any additive under optimized conditions. Scavenger experiments confirmed the formation of active species responsible for degradation. The degradation process was further supported by UV–Visible analysis, FT-IR identification of intermediates, and a significant reduction in total organic carbon (TOC) up to 82.92%. A plausible photocatalytic mechanism was proposed based on experimental findings. Importantly, the heterogeneous TBSAFPc catalyst demonstrated good stability and recyclability for five successive runs, as confirmed by 1 H NMR and FT-IR analysis. Furthermore, under optimized conditions, mass-scale degradation (250 mL) achieved 84.26% degradation efficiency, highlighting its potential for practical wastewater treatment applications. Visible-Light Photocatalytic RhB Degradation

Thiol synthesis from alkenes using elemental sulfur and hydrogen with cobalt-based heterogeneous catalysts

Hybrid waste-derived heterogeneous catalyst from waste banana peel and animal bone for efficient biodiesel synthesis from Jatropha curcas seed oil

The persistent accumulation of plastic waste poses severe environmental and economic challenges, and current management routes remain unsustainable. In recent years, catalytic hydroconversion has emerged as an attractive route to upcycle polyolefin plastics into fuels, lubricants, and value-added chemicals under comparatively mild conditions. Progress is, however, constrained by an incomplete mechanistic understanding of structure–performance relationships for these hydroconversion catalysts. This review summarizes recent advances in polyolefin hydrogenolysis and hydrocracking within a unified descriptor framework. We systematically examine key parameters, including metal particle size and electronic environment; the nature and architecture of the support material; metal–acid balance, proximity, and synergistic interactions; and polymer-specific effects such as adsorption entropy penalties, diffusion limitations, and processive conversion behaviour. Consolidating these insights, we propose practical design principles to guide the development of efficient, selective and stable catalysts for sustainable plastic upcycling. • Recent advances in heterogeneous catalytic hydroconversion of polyolefin plastics are critically reviewed. • Structure–performance relationships are elucidated using key mechanistic and materials-based descriptors. • Emerging perspectives and future research directions for sustainable plastic upcycling are identified.

Ultrahigh stable Bi-functional Zn(II)-CP as efficient heterogeneous catalyst for CO2 transformation and Cyanosilylation reaction

Waste of printed circuit boards as wet peroxide oxidation catalysts for venlafaxine degradation

L-proline-based organic-inorganic hybrid nickel phosphate as Noble-metal-free, recyclable heterogeneous catalyst for the multicomponent synthesis of tetrahydropyridines

ABSTRACT The development of cost‐effective and eco‐compatible nonnoble metal oxide catalysts for large‐scale propene production via nonoxidative propane dehydrogenation (PDH) is a key topic of current research in heterogeneous catalysis. Cobalt‐based catalysts show remarkable catalytic performance and are promising alternatives to industrially established platinum‐ or chromium oxide‐based catalyst systems. The formation of coke deposits under the reaction conditions has a significant influence on their performance. Time‐resolved operando Raman spectroscopic experiments have been performed during the PDH reaction using a catalyst system containing 3‐wt.% Co on silicalite‐1 as a support (3Co/S‐1) to elucidate the role of carbon‐containing species. Three stages during the PDH process were identified. During the initial 5 min on propane stream, propane is preferentially oxidized to carbon oxides and water. This indicates the removal of lattice oxygen from Co 3 O 4 , whereby this species is reduced to metallic cobalt (Co 0 ). With increasing time on propane stream, the formation of C 1 –C 2 hydrocarbons was observed, pointing to the occurrence of cracking and deep dehydrogenation reactions of propane. Subsequently, intense G and D bands appeared in the Raman spectrum due to the formation of carbon deposits. Simultaneously, there was a substantial enhancement in propene formation, which indicates that carbon‐containing species are necessary for the selective dehydrogenation of propane to propene. The catalyst showed high activity and durable operation in a series of seven dehydrogenation/reoxidation cycles under relevant conditions. The induction period observed for the fresh catalyst was shortened for the catalyst system in course of the PDH/reoxidation cycles.

Dual-atom catalysts (DACs) have triggered the burgeoning interest in the field of catalysis. The identification of coordination structures and the understanding of the catalytic role of dual-atom centers are of great significance to designing highly efficient DACs. This review summarizes the current synthesis methods for the construction of DACs. Then, we highlight the differences in geometric and electronic structures of DACs in terms of modulation strategies and engineering dual-metal interaction. In particular, the combination of various advanced characterizations and density functional theory (DFT) insights disclose the state of the dual-atom active center microenvironment. Moreover, the catalytic role of DACs in heterogeneous catalysis is discussed, involving the electronic effect of one metal as the main active center and the synergistic effect between dual metals. The structure-activity relationship and reaction mechanism based on experimental studies and theoretical exploration are discussed. Finally, the challenges and opportunities of DACs for the efficient valorization of energy-related small molecules are proposed. This review can offer new inspiration on developing DACs for energy conversion.

Supported catalysis is considered as an ideal catalytic mode as it combines the advantages of homogeneous catalysis (activity and selectivity) and heterogeneous catalysis (separation and recyclability). However, its application is greatly limited by the loss of catalytic performance after immobilization of molecular catalyst on supports. Inspired by the upright feeding posture of stalked crinoids-characterized by outstretched arms with ordered pinnules extending away from the substrate-we addressed this issue by immobilizing of a linear polymer catalyst decorated with aluminum porphyrin on silica. Our catalyst demonstrates remarkable productivity (62.4 kg polyols/g Al porphyrin), polymer selectivity (99%) and proton tolerance (320,000 equiv. to [Al]) under highly dilute conditions (0.000125 mol [Al]%, 17.8 ppm) for telomerization of CO2 and epoxides, which is greatly improved compared to traditional systems. Furthermore, our catalyst exhibits stability and maintains catalytic performance after three cycles. Our strategy provides a rational approach to designing highly efficient supported catalysts.

Engineering plastics such as polyoxymethylene (POM) are highly resistant to depolymerization due to their robust C─O backbones, posing a major challenge for sustainable recycling. Herein, we report a solid acid catalyst based on proton-exchanged montmorillonite (H-Mont) that efficiently upcycles POM into cyclic acetals under mild conditions. H-Mont exhibits high catalytic performance, converting both pristine and post-consumer POM, outperforming conventional solid and liquid acid catalysts in both catalytic efficiency and reusability. Mechanistic studies reveal that interlayer accessibility generated by solvent-induced swelling, together with strong Brønsted acidity of H-Mont, synergistically overcomes interfacial limitations between the catalyst and semi-crystalline POM, enabling efficient depolymerization. This represents the first demonstration of a streamlined, reusable heterogeneous catalysis for POM upcycling toward cyclic acetals and establishes a strategy for transforming chemically resilient engineering plastics into valuable chemicals.