Identification of the catalyst characteristics correlating with the key performance parameters including selectivity and stability is key to the rational catalyst design. Herein we focused on the identification of property-performance relationships in the methanol-to-olefin (MTO) process by studying in detail the catalytic behaviour of MFI, MEL and their respective intergrowth zeolites. The detailed material characterization reveals that both the high production of propylene and butylenes and the large MeOH conversion capacity correlate with the enrichment of lattice Al sites in the channels of the pentasil structure as identified by ²⁷Al MAS NMR and 3-methylpentane cracking results. The lack of correlation between MTO performance and other catalyst characteristics, such as crystal size, presence of external Brønsted acid sites and Al pairing suggests their less pronounced role in defining the propylene selectivity. Our analysis reveals that catalyst deactivation is rather complex and is strongly affected by the enrichment of lattice Al in the intersections, the overall Al-content, and crystal size. The intergrowth of MFI and MEL phases accelerates the catalyst deactivation rate.

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In Fe-based Fischer-Tropsch Synthesis (FTS), the Fe carbides form under the carburizing H₂ : CO reaction atmosphere providing the active phases for hydrocarbon synthesis. H₂ reduced Fe(−Na−S)/α-Al₂O₃ catalyst materials, with and without Na−S promotion, were carburized under CO at 240–440 °C to form Fe carbides. X-ray Powder Diffractometry (XRPD) with Rietveld Quantitative Phase Analysis (R-QPA) and Mössbauer Absorption Spectroscopy (MAS) were used to identity and quantify the formed Fe carbide phases. The Fe carbides formed in order of increasing temperature are ϵ-Fe₃C, η-Fe₂C, χ-Fe₅C₂ and θ-Fe₃C. θ-Fe₇C₃ and a distorted χ-Fe₅C₂ phase are formed at 25 bar CO (340 °C) from a Fe oxide precursor. Fe carbide formation was unaffected by Na−S addition, but it did increase Fe oxidation (≤290 °C) and preferred formation of χ-Fe₅C₂ over θ-Fe₃C phase (≥390 °C). The results unify the often ambiguous Fe carbide identification and nomenclature and specify the role of Na−S in the carburization process.

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In an era of globalized trade relations where food and pharmaceutical products cross borders effortlessly, consumers face counterfeit and deteriorated products at elevated rates. This paper presents multifunctional, biodegradable hydrogel microparticles that can provide information on the authenticity and the potential deterioration of the tagged food or pharmaceutical formulations. These microparticles integrate spatially patterned authenticity code with two sensors—the first one detects possible presence of pathogenic microbes through monitoring pH while the second one identifies products stored above optimal temperatures via optical monitoring of the microparticle degradation. Particles are synthesized from a biocompatible polymer and a photoinitiator, dextran modified with 2-hydroxyethylmethacrylate and riboflavin, respectively, using a continuous, high throughput method stop-flow lithography. The proposed synthesis approach also enables crosslinking with visible light bringing about additional flexibility to flow lithography. Model liquid and solid food and pharmaceutical products are successfully labeled with microparticles and the functionality of the sensors in aqueous solutions is demonstrated.@en