Search Results (504)

The Dry Reforming of Methane (DRM) is an efficient route to produce syngas (which is the feedstock for the production of synthetic fuels via the Fischer–Tropsch process) or hydrogen from methane and carbon dioxide. This work evaluates several nickel-based perovskite-type mixed oxides (La_xNiO₃, La_0.8Ni_0.9M_0.1O₃ (M = Co, Fe and Mn) and La_0.8Ni_1−yCo_yO₃) as precursors of the active phase (Ni) for the DRM reaction. Although La_0.8NiO₃ yields slightly smaller Ni particles after reduction, it promotes the accumulation of a significant amount of carbonaceous material during DRM. Partial Ni substitution with Co, Fe and Mn improves redox stability, with the La_0.8Ni_0.75Co_0.25O₃ formulation being the most effective for removing the carbonaceous deposits under a 25% CH₄, 25% CO₂ (50% He) reactant atmosphere. However, when this formulation is used as a catalyst precursor for DRM under more realistic conditions (i.e., employing a feed that simulates real biogas), CH₄ conversion and H₂ yield decrease, and the carbon accumulated increases due to the greater influence of the parallel reactions. As a positive sign for future applications or research, under these conditions, the addition of 0.5% O₂ to the feed and the use of a CO₂ regeneration step decreased the amount of carbonaceous material deposited. Full article

Background: Pathological activation of oxidative metabolism is a universal catalyst for liver parenchyma destruction. While physiological pools of reactive oxygen and nitrogen species (ROS/RNS) regulate hepatic regeneration and cellular respiration, decompensation of endogenous antioxidant systems induces cascading damage across hepatocytes, sinusoidal endothelial cells, Kupffer macrophages, and hepatic stellate cells. Current therapies against liver fibrosis, cirrhosis, and hepatocellular carcinoma remain suboptimal, necessitating the identification of novel, druggable molecular targets. Focus: This review synthesizes current evidence on ROS-driven necroinflammatory and degenerative cascades and evaluates the multi-level protective potential of the selenoprotein family. Evidence: Selenoproteins function as a highly heterogeneous network where specific members are vital for cell survival (e.g., GPX4 in preventing ferroptosis), while others exhibit stage-dependent expression throughout progression from inflammation to malignancy. Conclusions: In addition to directly scavenging free radicals, selenoproteins modulate endoplasmic reticulum stress, metabolic remodeling, and immune responses. A more complete understanding of the important role of selenoproteins in regulating liver pathological processes, particularly their antioxidant function, allows them to be considered as promising potential targets for the further development of pharmacotherapeutic strategies for the treatment of chronic liver diseases. Full article

Hierarchical porous catalysts now benefit from intentional co-design of transport pathways and catalytic functionality. This review critically examines intelligent micro–mesoporous nanoarchitectures, emphasizing pore connectivity and active-site cooperativity as inseparable design principles. We first outline limitations of purely microporous systems (diffusion constraints, site inaccessibility, deactivation) and then show how multi-scale networks overcome these issues. Engineering strategies for pore connectivity involving bottom-up templating, post-synthetic reconstruction, top-down desilication/dealumination are systematically reviewed alongside metrics (tortuosity, connectivity, accessibility). Active-site cooperativity is examined via acid-based bifunctionality, metal-acid coupling, single-atom catalysis and compartmentalized architectures for cascade reactions. The central thesis is that optimal performance emerges when transport and catalytic site engineering are coupled, supported by evidence from zeolites, metal–organic frameworks, silica nanoreactors, heteroatom-doped carbons and advanced electrocatalysts. Applications include biomass upgrading, selective oxidation, and energy conversion. The review also covers stability, deactivation, and regeneration, suggests standardized reporting criteria, and highlights future challenges such as using AI for catalyst design, operando transport mapping, scalable catalyst synthesis, and programmable catalytic nanoarchitectures. This review offers a predictive design strategy for next-generation multifunctional catalytic materials by focusing on the integrated transport-reaction system instead of only focusing on the structure. Full article

Hydrogen sulfide (H₂S) removal with simultaneous sulfur recovery is essential for natural gas, refinery, and biogas processing because of the toxicity and corrosivity of H₂S. However, conventional Claus sulfur recovery is energy-intensive, operates at high temperatures, and requires multiple processing units, creating a need for efficient low-temperature alternatives. In this study, the redox-active ionic liquid 1-butyl-3-methylimidazolium tetrachloroferrate ([BMIM][FeCl₄]) was investigated as both an absorbent and catalyst for the direct oxidation of H₂S to elemental sulfur. Experiments were conducted in a laboratory-scale semi-batch single-bubble reactor at 25–100 °C and 500–3000 ppm H₂S. Under the optimum operating conditions, H₂S conversion exceeded 99%, with removal efficiency increasing from 95.0% at 25 °C to 99.1% at 100 °C within 60 min. Kinetic analysis revealed first-order reaction kinetics with respect to H₂S and Fe(III), with apparent rate constants increasing from 0.0506 to 0.0636 min⁻¹ over the investigated temperature range and an apparent activation energy of 2.78 kJ mol⁻¹. Hatta number analysis confirmed that the process operated predominantly in the reaction-controlled regime. Raman spectroscopy showed the attenuation of [FeCl₄]⁻ vibrational bands together with the appearance of characteristic S₈ bands, while X-ray diffraction (XRD) verified the formation of crystalline elemental sulfur. CHNS analysis provided complementary elemental evidence for sulfur formation. The ionic liquid exhibited excellent thermal stability (>320 °C) and retained 92–95% of its initial activity after repeated regeneration cycles. These findings demonstrate that [BMIM][FeCl₄] effectively integrates H₂S absorption and catalytic oxidation within a single liquid phase, providing a promising low-temperature and energy-efficient alternative to conventional sulfur recovery technologies. Full article

This study explores the role of arts-based educational interventions in fostering social mending and urban regeneration in disadvantaged urban contexts. The intervention consisted of participatory mosaic workshops designed to foster cooperation, inclusion, and civic engagement, culminating in the co-creation of public artworks installed in a degraded urban underpass and included 193 children aged 5–15 living in Tor Bella Monaca, a highly marginalized suburb of Rome (Italy). The analysis of the intervention used a mixed-methods approach, based on systematic observation, questionnaires, interviews, and document analysis. The findings indicate that the artistic process acted as a catalyst for both individual and collective transformation: at the individual level, participation enhanced relational skills, emotional expression, and sense of agency; at the community level, the intervention contributed to the reactivation of public space, increased social cohesion, and improved care for the urban environment. We interpret these outcomes through the capability approach, identifying art as a “conversion factor” linking individual capabilities to collective regeneration. The intervention aligns with SDGs 4, 10, 11, and 17 of the 2030 Agenda and supports the relevance of scalable, community-based models for inclusive and sustainable urban policies in deprived areas. Full article

The electrochemical regeneration of sodium borohydride (NaBH₄) from spent metaborate is a central bottleneck for circular hydrogen storage. (1) Background: The eight-electron reduction of the aqueous borate species B(OH)₄⁻ to BH₄⁻ is thermodynamically out-competed by the hydrogen-evolution reaction (HER) by about 0.41 V at every pH, so selectivity can only be won kinetically. (2) Methods: We advance an ambiphilic-site hypothesis, screen 30 candidate metal centres using entirely experimental, tabulated descriptors (bulk HER exchange current density; gas-phase M-O bond energy) with no new electronic-structure computation, and then audit the transferability of both descriptor axes against published, corrected DFT datasets for nitrogen-coordinated single-atom sites. (3) Results: At the parent-metal level, the two axes are orthogonal (Spearman ρ = 0.02) and the score passes a family-level experimental validation over seven bulk-electrode metals (ρ = 0.69; exact permutation p = 0.050), separating the HER-dominated noble-metal family from the single-atom Mn benchmark. The site-level audit shows that the oxophilicity axis transfers to M-N₄ sites almost quantitatively (ρ = −0.84 pyridine-4N, −0.95 pyrrole-4N, n = 23) while the bulk HER axis does not, and that site-level scaling between oxygen and hydrogen binding narrows the productive window to oxophilic centres that over-bind hydrogen. (4) Conclusions: The site-anchored screen redirects the search from the parent-metal leaders (La, Ce, Y, Ti, Sc) to refractory single-atom centres, with W, Nb and Mo as priority synthesis targets (Re excluded on scarcity; Zr, Hf, Ta as data-supported extensions; Ti as the sustainability-anchored borderline case) and the lanthanides retained only as explicitly extrapolative candidates. All data and analysis code are openly deposited. Full article

A key challenge facing modern society, fueled by the relentless growth in energy and food requirements, is meeting rising energy needs without exacerbating greenhouse gas emissions. Nevertheless, fossil fuel combustion remains the primary contributor to human-induced pollution. As environmental concerns intensify and fossil resources become increasingly scarce, there is a growing push within the research community to identify alternative energy carriers and to advance more sustainable, low-impact technologies. Thus, this review focuses on catalytic CH₄ decomposition (CDM) for hydrogen production over Ni-, Fe, and Co-metal-based catalysts. Fe-based catalysts have received considerable attention for CDM due to their low cost and environmental sustainability. Furthermore, a discussion of deactivation and regeneration, along with the identified reaction mechanisms of CH₄ decomposition over these catalysts, is presented. Full article

A major limitation hindering the practical application of heterogeneous Fenton-like systems is their inherently slow reaction kinetics, particularly near neutral pH. To address this issue, a hydroxylamine (HA)-enhanced NiFe₂O₄/H₂O₂ system was developed for phenol degradation. At an initial pH of 7, with 5 mmol/L HA and 10 mmol/L H₂O₂, the system achieved 97.8% phenol degradation within 60 min, compared with 17.4% in the HA-free system. XPS analysis showed that the Fe²⁺ proportion increased from 49.1% to 53.6% and the Ni²⁺ proportion increased from 52.1% to 63.4% after reaction. These changes are consistent with HA facilitating the formation or regeneration of reduced metal species, suggesting that HA may be related to accelerated Fe³⁺/Fe²⁺ or Ni³⁺/Ni²⁺ cycling. Radical scavenging experiments and electron paramagnetic resonance (EPR) results indicated that identified hydroxyl (•OH) and superoxide (O₂•⁻) radicals were the predominant reactive species. Metal-leaching and catalyst-removal experiments indicated that both heterogeneous and homogeneous processes contributed to phenol degradation. The results provide mechanistic insights into HA-enhanced H₂O₂ activation while also highlighting the need to consider metal leaching, HA-derived nitrogen products, and catalyst reusability. Full article

This study reports an ionic-liquid (IL)-enabled strategy for engineering chitin nanofiber supports that allows for the formation of monometallic Pd, Ag, and Au catalysts, as well as Pd–Au co-loaded catalyst. High-molecular-weight chitin, extracted from shrimp shells using 1-ethyl-3-methylimidazolium acetate ([C₂C₁im][OAc]), is regenerated and electrospun into free-standing nanofiber mats, followed by partial deacetylation of the accessible nanofiber interface to introduce primary amine functionalities while largely preserving the chitin crystalline framework. Metal precursors were first immobilized at the modified chitin nanomat interface at pH ≈ 2, followed by nanoparticle formation upon exposure to alkaline borate buffer (pH ≈ 9.2–10). STEM analysis shows particle sizes of Pd 3.2 ± 1.0 nm, Au 6.4 ± 2.6 nm, and Ag 2.6 ± 1.2 nm. The co-loaded Pd–Au sample likewise exhibited nanoscale, well-dispersed particles with no large aggregates observed within the examined STEM regions. Catalytic performance is evaluated using the Suzuki–Miyaura coupling of bromobenzene with phenylboronic acid as a benchmark reaction. The Pd–chitin nanomats achieve >99% conversion and ≥99% selectivity at gravimetrically estimated Pd loadings as low as 0.012–0.017 mol% under the conditions examined. Full article

Developing electrocatalysts with high stability under industrial current densities is crucial for practical water electrolysis toward green hydrogen production yet remains a formidable challenge. Here, Fe₄₀Ni₃₈Mo₄B₁₈ amorphous alloy ribbons are fabricated via a scalable single-roller melt-spinning method and used as self-supported oxygen evolution electrodes. The as-prepared amorphous alloy sustains continuous operation at 500 mA cm^–2 for 730 h before noticeable deactivation. Mechanistic investigations reveal that under high-current anodic conditions, surface reconstruction accompanied by Fe dissolution leads to the formation and accumulation of a Fe-depleted, Ni-rich (oxy)hydroxide passivation layer, resulting in reduced Ni–Fe synergistic sites and limited charge transfer. Based on this understanding, a rapid regeneration strategy is developed to remove the inactive surface layer and induce structural reconfiguration. The regenerated electrode exhibits reduced overpotential at 10 mA cm^–2 (from 304 to 243 mV) and sustains an additional 710 h of operation at 500 mA cm^–2 at a lower applied potential. These results indicate that catalyst deactivation and regeneration are governed by surface chemical evolution and provide insight into extending catalyst lifetime under practical operating conditions. Full article

To reduce dependence on fossil fuels and limit their environmental impact, the development of biofuels represents an effective strategy. Green diesel is a biofuel synthesized from vegetable oil that is fully compatible with conventional diesel engines and therefore represents a promising alternative to mineral diesel. In addition, the use of waste-derived catalysts can further improve the sustainability of the process. In this study, fly ash cenospheres (FAC), an abundant industrial waste, were used as a support to synthesize several transition-metal-based catalysts. The catalysts were tested for the catalytic deoxygenation of vegetable oils in a batch reactor at 320 °C and 40 bar H₂ using 10 wt% catalyst and n-hexane as the solvent. Among the tested catalysts, NiMo(5/15)/FAC exhibited the best performance, achieving complete conversion and producing a biofuel containing 91.7% C₁₅–C₁₈ hydrocarbons. The physicochemical properties of the catalyst were investigated using ICP-MS, FT-IR, XRD, and BET-BJH analyses. The effects of the solvent, feedstock, and catalyst reuse were also evaluated. In the recycling tests, the catalyst activity rapidly decreased; however, the regeneration step fully restored its catalytic performance. These results show that FAC can be effectively valorized as a catalyst support for green diesel synthesis. Full article

Thermochemical conversion of nitrogen- and sulfur-rich biomass-derived wastes, such as sewage sludge, algae, and agricultural residues, is a promising route for renewable fuel production and waste valorization. However, fuel-bound nitrogen can be released as NH₃, HCN, and HNCO, while sulfur species such as H₂S, SO₂, and COS accelerate catalyst deactivation and generate NO_x/SO_x precursors. Metal-loaded ZSM-5 catalysts are attractive for clean catalytic pyrolysis because they combine the MFI pore confinement and tunable Brønsted/Lewis acidity of ZSM-5 with the hydrogen transfer, dehydrogenation, cracking, redox, and sulfur-tolerance functions of metal species. This review critically summarizes recent advances in metal-loaded ZSM-5 catalysts for catalytic denitrogenation of biomass-derived solid wastes. The formation and migration of NH₃, HCN, HNCO, tar-N, and char-N are first discussed to clarify the chemical basis of fuel-N conversion. The effects of ZSM-5 pore structure, acid-site distribution, Si/Al ratio, hierarchical porosity, and synergy on adsorption, diffusion, C-N bond cleavage, heterocyclic-N ring-opening, aromatization, and nitrogen redistribution are then analyzed. Catalyst deactivation under realistic pyrolysis atmospheres is also highlighted, including coke deposition, metal sintering, framework dealumination, mineral poisoning, and H₂S/SO₂/COS-induced sulfur poisoning. Finally, future directions are proposed for designing multifunctional ZSM-5-based catalysts integrating denitrogenation activity, sulfur resistance, coke resistance, regenerability, and quantitative nitrogen/sulfur mass balance. Full article

Efficient component separation is a prerequisite for high-value recycling of blended textile waste. Herein, a two-stage metal-free recycling process for wool/polyamide 6 (PA6) carpet waste is developed, combining mild acid-assisted selective separation with monomer-level PA6 regeneration. Acetic acid pretreatment at 80 °C removes surface dyes, followed by formic acid treatment for selective PA6 dissolution. Both acids are efficiently recyclable via low-temperature rotary evaporation, with an average PA6 recovery yield over 75% across five consecutive cycles. Recovered wool preserves its original scale structure and tensile strength comparable to virgin fibers, and reclaimed PA6 maintains its macromolecular and crystalline structure, verifying the mildness of the separation protocol. The recovered PA6 is further depolymerized via a microwave-assisted acetic anhydride/organobase system, where the phosphazene base ^tBuP₄ achieves a maximum N-acetyl-ε-caprolactam yield of 74.6%. Depolymerization efficiency is governed by catalyst basicity, nucleophilicity, and acetic anhydride-mediated polyamide backbone activation. After deacetylation, the resulting ε-caprolactam is repolymerized with the same ^tBuP₄ catalyst, producing regenerated PA6 with chemical structure and thermal properties nearly identical to virgin PA6. Full article

The article addresses the challenges associated with processing heavy petroleum feedstock with high metal content in the Resid Fluid Catalytic Cracking (RFCC) unit of the Atyrau Oil Refinery. Elevated concentrations of iron, nickel, and vanadium were shown to cause rapid catalyst deactivation, deterioration of fluidization properties, and instability of the reactor–regenerator system. Analysis of industrial data revealed that the iron content in the feed significantly exceeded the design value, reaching 150 mg/kg, which resulted in increased catalyst consumption and reduced process efficiency. The industrial application of metal-passivating chemical reagents reduced the iron content by 48–62%, thereby improving catalyst performance and increasing the yield of target products. However, the use of these reagents is associated with high operating costs. Therefore, additional demetallization methods were investigated, particularly solvent deasphalting. Experimental studies on a pilot unit demonstrated that deasphalting reduced the concentrations of Fe, Ni, and V by 7–9 times and produced a deasphalted oil yield of 81.1 wt.%. The obtained product exhibited low Conradson carbon residue and improved quality, making it suitable as a feed component for catalytic cracking. An integrated approach combining chemical treatment and solvent deasphalting is proposed to improve refining efficiency and catalyst stability. Full article

The sustainable regeneration of industrial heritage in cold regions is constrained by severe winter climates, pronounced seasonal shifts in behavior, and declining spatial vitality. However, existing studies have not sufficiently explained how cold-climate conditions reshape catalyst effects and regeneration performance in industrial heritage districts. This study proposes a digital shadow-enhanced and digital twin-enabled analytical framework for the sustainable regeneration of cold-region industrial heritage. Using the Youfang Street industrial heritage district in Harbin, China, as an exploratory case, the framework integrates multi-source data to construct a dynamic assessment system linking climatic constraints, spatial structure, and human activity patterns. The climate correction coefficient is further operationalized through normalized climatic variables, including air temperature, wind speed, snow-cover condition, and thermal-comfort indicators. The results indicate that winter conditions substantially weaken traditional catalyst mechanisms by reducing outdoor interaction, disrupting movement continuity, and increasing dependence on indoor transitional spaces. Simulation results further demonstrate that climate-responsive interventions, including enhanced indoor connectivity, mixed-use functional integration, and seasonal activity optimization, can improve regeneration performance and spatial resilience. The framework is presented as an exploratory single-case analytical model that requires further multi-city and multi-year validation. By combining digital shadow-supported simulation with sustainable urban regeneration theory, this study provides a transferable analytical framework and practical decision-support tool for industrial heritage revitalization in cold-region cities. Full article