AD
A.I. Dugulan
93 records found
1
Dark etching regions (DERs) are a widely studied phenomenon in the context of sub-surface microstructure decay in rolling bearings. These regions result from dislocation motion (plasticity) and carbon migration due to rolling contact fatigue (RCF). We conducted a systematic study
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The removal of carbon deposits from carburized Fe-based Fischer–Tropsch catalysts is a critical aspect of their performance. In this study, a method is presented to remove carbon deposits from freshly prepared χ-Fe5C2. The method involves successive passivation and reduction step
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In recent years growing interest has been placed on the role of dopant concentrations of tertiary precious and base metals in modifying the performance of supported AuPd nanoalloys towards the direct synthesis of H
2O
2. Within th
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Vivianite presents a significant phosphorus pool in iron-rich, reducing environments, necessitating the development of an affordable and routine quantification method. A novel extraction protocol using 2,2′-bipyridine (Bipy) was proposed as a promising approach. However, the effi
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Tuning stability of titania-supported Fischer-Tropsch catalysts
Impact of surface area and noble metal promotion
Cobalt oxidation is a relevant deactivation pathway of titania-supported cobalt catalysts used in Fischer-Tropsch synthesis (FTS). To work towards more stable catalysts, we studied the effect of the surface area of the titania support and noble metal promotion on cobalt oxidation
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Iron-modified Al-ZSM-5 increases selectivity to propene, a key petrochemical resulting from fluid catalytic cracking (FCC). However, the type and role of active iron species remain unclear, hindering efforts to streamline the design of selective FCC additives. Here, we investigat
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CO2 hydrogenation to chemicals and fuels has the potential to alleviate CO2 emissions and displace fossil resources simultaneously via consecutive RWGS and FTS reactions, also known as CO2-FTS. As Fe-based catalysts are active and selective for bo
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Multifunctional, biocompatible magnetic materials, such as iron oxide nanoparticles (IONPs), hold great potential for biomedical applications including diagnostics (e.g., MRI) and cancer therapy. In particular, they can play a crucial role in advancing cancer thermotherapy by gen
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While Eu2+ → Eu3+ energy transfer is well known, in this study the energy transfer from Eu3+ to Eu2+ is reported for the first time. The predominant condition for Eu3+ → Eu2+ energy transfer is a Eu2+ 4f
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Oil has long been the dominant feedstock for producing fuels and chemicals, but coal, natural gas and biomass are increasingly explored alternatives. Their conversion first generates syngas, a mixture of CO and H2, which is then processed further using Fischer–Tropsch (FT) chemis
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Iron oxide-based adsorbents showed potential to reach ultra-low phosphorus (P) concentrations to prevent eutrophication and recover P. High affinity, high capacity at low P concentrations (<1 mg L−1), good stability, and reusability of the adsorbent are key factors
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Robust magnetic vivianite recovery from digested sewage sludge
Evaluating resilience to sludge dry matter and particle size variations
Phosphorus recovery via vivianite extraction from digested sludge has recently gained considerable interest. The separation of vivianite was demonstrated earlier at the pilot scale, and operational parameters were optimized. In this study, we tested the robustness of this technol
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The influence of chromium and aluminium doping on the over-reduction during activation of iron-oxide-based water-gas shift catalysts was investigated using Mössbauer spectroscopy for the first time. In situ Mössbauer spectra of catalysts exposed to industrially relevant gas compo
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In this contribution, we outline the efficacy of Pd-based bimetallic catalysts toward the oxidative upgrading of benzyl alcohol via the in situ synthesis of H2O2 (and related reaction intermediates) from the elements. In particular, the formation of PdAu and
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Zero thermal expansion (ZTE) materials with the advantage of an invariable length with varying temperatures are in high demand for modern industry but are relatively rare for metals. Fe-based Laves phases attract significant attention due to the rich and intriguing physical prope
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The eutrophic Bouvigne pond (Breda, The Netherlands) regularly suffers from cyanobacterial blooms. To improve the water quality, the external nutrient loading and the nutrient release from the pond sediment have to be reduced. An enclosure experiment was performed in the pond bet
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CO2 hydrogenation is an attractive way to store and utilize carbon dioxide generated by industrial processes, as well as to produce valuable chemicals from renewable and abundant resources. Iron catalysts are commonly used for the hydrogenation of carbon oxides to hydr
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Revisiting the Electrochemical Nitrogen Reduction on Molybdenum and Iron Carbides
Promising Catalysts or False Positives?
The electrochemical dinitrogen reduction reaction (NRR) has recently gained much interest as it can potentially produce ammonia from renewable intermittent electricity and replace the Haber-Bosch process. Previous literature studies report Fe- and Mo-carbides as promising electro
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FeOOH and (Fe,Zn)OOH hybrid anion exchange adsorbents for phosphate recovery
A determination of Fe-phases and adsorption–desorption mechanisms
Hybrid anion exchange adsorbents (HAIX) seem promising to prevent eutrophication and recover phosphate (P). HAIX consist of an anion exchange resin (AIX) backbone, promoting anion physisorption (outer-sphere complex), impregnated with iron (hydr)oxide nanoparticles (NPs), for sel
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Non-oxidative coupling of methane is a promising route to obtain ethylene directly from natural gas. We synthesized siliceous [Fe]zeolites with MFI and CHA topologies and found that they display high selectivity (>90 % for MFI and >99 % for CHA) to ethylene and ethane among
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