Catalytic pyrolysis of fish waste oil using ZSM-5 catalyst for the production of renewable biofuel.

This present study enlightens the eco-friendly green synthesis of ZSM-5 from natural clay montmorillonite, and its proper incorporation with 'Ni'. Nickle (Ni) was wet impregnated onto HZSM-5 and the resulting catalyst was characterized by various techniques including XRD, BET, N2 Sorption Studies, TPD, SEM and TEM techniques. The SEM images revealed the uniform distribution of Ni over HZSM-5 zeolite catalyst and the XRD results indicated the undistorted crystalline structure of HZSM-5 even after impregnation of Ni. The latter part of the work concentrates on the strength of the catalyst in cracking oil derived from discarded fish parts. Discarded fish waste was pyrolyzed to obtain the fish oil, which was then used for cracking studies. The fish oil was efficiently converted (99% conversion) by Ni/ZSM5 (50 wt %) and yielded 70% liquid fractions, which formed gasoline (78.6%), kerosene (12.3%) and diesel (9.1%). The research is a complete parcel to examine the working potential of the produced biofuel in pre-existing engines. The quality of gasoline fraction was tested according to ASTM standards, which showed that the heating value was slightly lower compared to fossil gasoline. The torque and brake fuel consumption were also examined and it indicated that the fish oil derived gasoline fuel may need to be mixed with the commercial gasoline to optimize its performance.

Synergistic Catalysis of Water-Soluble Exogenous Catalysts and Reservoir Minerals during the Aquathermolysis of Heavy Oil.

Oil serves as the essential fuel and economic foundation of contemporary industry. However, the use of traditional light crude oil has exceeded its supply, making it challenging to meet the energy needs of humanity. Consequently, the extraction of heavy oil has become crucial in addressing this demand. This research focuses on the synthesis of several water-soluble catalysts that can work along with reservoir minerals to catalyze the hydrothermal cracking process of heavy oil. The goal is to effectively reduce the viscosity of heavy oil and lower the cost of its extraction. Based on the experimental findings, it was observed that when oil sample 1 underwent hydrothermal cracking at a temperature of 180 °C for a duration of 4 h, the amount of water added and catalyst used were 30% and 0.2% of the oil sample dosage, respectively. It was further discovered that the synthesized Mn(II)C was able to reduce the viscosity of oil sample 1 by 50.38%. The investigation revealed that the combination of Mn(II)C + K exhibited a significant synergistic catalytic impact on reducing viscosity. Initially, the viscosity reduction rate was 50.38%, which climbed to 61.02%. Subsequently, when catalyzed by the hydrogen supply agent isopropanol, the rate of viscosity reduction rose further to 91.22%. Several methods, such as freezing point analysis, thermogravimetric analysis, DSC analysis, component analysis, gas chromatography, wax crystal morphology analysis, and GC-MS analysis, were conducted on aqueous organic matter derived from heavy oil after undergoing different reaction systems. These analyses confirmed that the viscosity of the heavy oil was decreased. By studying the reaction mechanism of the model compound and analyzing the aqueous phase, the reaction largely involves depolymerization between macromolecules, breakdown of heteroatom chains, hydrogenation, ring opening, and other related consequences. These actions diminish the strength of the van der Waals force and hydrogen bond in the recombinant interval, impede the creation of a grid-like structure in heavy oil, and efficiently decrease its viscosity.

Study on the Regeneration of Waste FCC Catalyst by Boron Modification.

Regeneration has been considered as an ideal way for the post-treatment of waste FCC catalyst (ECat). In this work, the degeneration mechanism of ECat was firstly researched and attributed to the increasing of strong acid sites accessibility of ECat in contrast with fresh FCC catalyst by adsorption FTIR. Based on the proposed degeneration mechanism, ECat was successfully regenerated through suitable weakening for strong acid sites by boron modification. Characterization and evaluation results suggested that, the strong acid sites of regenerated ECat (R-ECat) were apparently decreased by boron modification which had significantly improve the heavy oil catalytic cracking performance of R-ECat. Because of the excellent performance, R-ECat in this work could successfully substitute for partial fresh FCC catalyst in FCC unit, which would provide a practicable way for the reutilization of ECat.

The Coking of a Solid Catalyst Rationalized with Combined Raman and Fluorescence Lifetime Microscopy.

The formation of carbon deposits is a major deactivation pathway for solid catalysts. Studying coking on industrially relevant catalysts is, however, often challenging due to the sample heterogeneity. That is especially true for zeolite-containing catalysts where fluorescence often hampers their characterization with Raman spectroscopy. We turned this disadvantage into an advantage and combined Raman and fluorescence (lifetime) microscopy to study the coking behavior of an equilibrium catalyst material used for fluid catalytic cracking of hydrocarbons. The results presented illustrate that this approach can yield new insights in the physicochemical processes occurring within zeolite-containing catalyst particles during their coking process. Ex situ analyses of single catalyst particles revealed considerable intra-sample heterogeneities. The sample-averaged Raman spectra showed a higher degree of graphitization when the sample was exposed to more hexane, while the sample-averaged fluorescence lifetime showed no significant trend. Simultaneous in situ Raman and fluorescence (lifetime) microscopy, used to follow the coking and the regeneration of single particles, gave more insights in the changing fluorescence dynamics. During the coking, the rise and decline of the average fluorescence lifetime suggested the prolonged presence of smaller coke species that are quenched more and more by adjacent larger polyaromatics acting as Förster-resonance-energy-transfer acceptors.

Enhanced degradation of VOCs from biomass gasification catalyzed by Ni/HZSM-5 series catalyst.

Volatile organic compounds (VOCs) evolved from biomass gasification plays a positive role in the formation of PM2.5 and odor pollution. In order to improve the removal rate of various VOCs produced by biomass gasification, a nickel-based supported HZSM-5 cataly st (Ni/HZSM-5 and Ni-Ca-Co/HZSM-5) was prepared by different auxiliary methods, Ni loadings, and pyrolysis temperatures. The catalytic cracking performance of Ni/HZSM-5 catalysts for different VOCs model compounds such as toluene, phenol, furan, acetic acid and cyclohexane were studied in a fixed-bed reactor. The catalysts were further characterized and analyzed by XRD, SEM, XPS and BET. The results showed that the Ni/HZSM--C-Co5 catalyst prepared by ultrasonic-assisted excess impregnation method with Ni loading of 8 wt%, Ca loading of 4 wt%, Co loading of 0.1 wt% had strong catalytic activity for VOCs degradation. With the increase of the cracking temperature, the conversion rate and gas yield of from model compound cracking improved significantly. At 800 °C, the conversion of each model compound was more than 90%, accompanied by the generation of cracking gases such as H2 and CH4. The selectivity of H2 and CH4 from toluene cracking reached 93%, and cyclohexane reached 98%. The models with higher oxygen content and lower bond energy were more likely to undergo reforming reaction to form small molecular gas. Model compounds with large molecular weight and high carbon content provided more carbon sources. Under the conversion degree towards the gas direction was high. This study provides a new idea on the removal of VOCs for the efficient utilization of biomass resources.

Pyrolysis of COVID-19 disposable masks and catalytic cracking of the volatiles.

The disposable masks generated in the battle against COVID-19 has attracted wide attention in the world. Pyrolysis can convert the masks into useful chemicals and fuels. In this work, the masks are pyrolyzed at temperatures of 400-580 °C and the volatiles generated are cracked without or with catalysts at 440-580 °C. The catalysts used include metal oxides (Al2O3, kaolin, Fe2O3, CeO2, TiO2) and molecular sieves (HZSM5, HY, ß(25H), ß(60H)). The yields and composition of gas and liquid products are studied in detail where the tetrahydrofuran (THF) soluble compounds are defined as the liquid product and the n-hexane soluble compounds are defined as the oil. The liquid product and the oil were identified by GC-MS and quantified by GC. Results indicate that 440 °C is sufficient for the masks' pyrolysis and the yields of gas, liquid product and oil are 23.4, 74.7 and 42.1 wt%, respectively. About 30% of the liquid product are C6-C35 hydrocarbons while about 70% are C36-C70 hydrocarbons trapped in the GC column (termed as column residue). The gas products are mainly C5, propylene and butene, accounting for 54.8%, 22.8% and 14.5% of the total gas product, respectively. Cracking of volatiles over various catalysts converts the liquid product mainly to propylene, butene and smaller organic gases. TiO2, HY and ß(60H) are good catalysts, especially ß(60H), which increases the yield of gas product to 86.5 wt% with 73.0% being ethylene, propylene and butene at 580 °C.

Realizing Fast Synthesis of High-Silica Zeolite Y with Remarkable Catalytic Performance.

High-silica zeolite Y (FAU) plays a vital role in (petro)chemical industries. However, the slow nucleation and growth kinetics of the high-silica FAU framework limit its direct synthesis and the improvement of framework SiO2 /Al2 O3 ratio (SAR). Here, a facile strategy is developed to realize the fast crystallization of high-silica zeolite Y, which involves the combination of high crystallization temperature, ultra-stable Y (USY) seeds and efficient organic-structure directing agent (OSDA). The synthesis can be finished in 5-16 h at 160 °C and with tunable SAR up to 18.2, and the key factors affecting crystallization kinetics and phase purity are elucidated. Moreover, the crystallization process was monitored to reveal the fast crystal growth mechanism. The high-silica products possess high (hydro)thermal stability and abundant strong acid sites, which endow them excellent catalytic cracking performance, obviously superior to commercial USY.

Controlling liquid hydrocarbon composition in valorization of plastic waste via tuning zeolite framework and SiO2/Al2O3 ratio.

Abundance of plastic waste has become threat to the mankind and aquatic life and thus needs to be recycled or converted into value added products. Liquefaction of waste plastics via catalytic cracking is one the efficient routes towards plastic waste management. Concerning this, in present study, conversion of polymer mixture containing polypropylene, low-density polyethylene and high-density polyethylene (PP, LDPE and HDPE) was done for the production of gasoline and diesel range hydrocarbons using two-step cracking approach. MWW and MFI (12 and 10 member ring structures respectively) type zeolites having different pore structure and acidity were used for catalytic cracking of polymer feed at 350 °C. Investigations revealed that MWW type zeolite having two independent pore channels selectively provides gasoline range of hydrocarbons (C7-C12, 99.12%) in polymer cracking reaction as compared to MFI type which results in C13-C20 range of hydrocarbons (73.19%). Hydrocarbon compositions were confirmed from GC-MS, 1H, 13C NMR and FT-IR techniques. In activity results it was observed that acidity of zeolites affects the liquid yield and hydrocarbon distribution as analysed by using zeolites of two different SiO2/Al2O3 (SAR) ratio (30 and 55) which directs that zeolite (MFI/MWW) with lower SAR (30) having higher acidity results in higher yield of fuel range liquid hydrocarbons as compared to higher SAR (55) zeolite. Characterization studies such as XRD, N2-physisorption, NH3-TPD, FE-SEM and EDX were performed to check the physiochemical properties of zeolite and correlated with the activity. Overall, the present investigation provides detailed comparative study on plastic degradation using MFI and MWW type zeolites resulting into different range of liquid hydrocarbons.

Research on Hazardous Waste Removal Management: Identification of the Hazardous Characteristics of Fluid Catalytic Cracking Spent Catalysts.

Fluid catalytic cracking (FCC) spent catalysts are the most common catalysts produced by the petroleum refining industry in China. The National Hazardous Waste List (2016 edition) lists FCC spent catalysts as hazardous waste, but this listing is very controversial in the petroleum refining industry. This study collects samples of waste catalysts from seven domestic catalytic cracking units without antimony-based passivation agents and identifies their hazardous characteristics. FCC spent catalysts do not have the characteristics of flammability, corrosiveness, reactivity, or infectivity. Based on our analysis of the components and production process of the FCC spent catalysts, we focused on the hazardous characteristic of toxicity. Our results show that the leaching toxicity of the heavy metal pollutants nickel, copper, lead, and zinc in the FCC spent catalyst samples did not exceed the hazardous waste identification standards. Assuming that the standards for antimony and vanadium leachate are 100 times higher than that of the surface water and groundwater environmental quality standards, the leaching concentration of antimony and vanadium in the FCC spent catalyst of the G set of installations exceeds the standard, which may affect the environmental quality of surface water or groundwater. The quantities of toxic substances in all spent FCC catalysts, except those from G2, does not exceed the standard. The acute toxicity of FCC spent catalysts in all installations does not exceed the standard. Therefore, we exclude "waste catalysts from catalytic cracking units without antimony-based passivating agent passivation nickel agent" from the "National Hazardous Waste List."

Preparation of Sorbents Containing Straetlingite Phase from Zeolitic By-Product and Their Performance for Ammonium Ion Removal.

In this study, straetlingite-based sorbents were used for NH4+ ion removal from a synthetic aqueous solution and from the wastewater of an open recirculation African catfish farming system. This study was performed using column experiments with four different filtration rates (2, 5, 10, and 15 mL/min). It was determined that breakthrough points and sorption capacity could be affected by several parameters such as flow rate and mineral composition of sorption materials. In the synthetic aqueous solution, NH4+ removal reached the highest sorption capacity, i.e., 0.341 mg/g with the S30 sorbent at a filtration rate of 10 mL/min and an initial concentration of 10 mg/L of NH4+ ions. It is important to emphasize that, in this case, the Ce/C0 ratio of 0.9 was not reached after 420 min of sorption. It was also determined that the NH4+ sorption capacity was influenced by phosphorus. In the wastewater, the NH4+ sorption capacity was almost seven times lower than that in the synthetic aqueous solution. However, it should be highlighted that the P sorption capacity reached 0.512 mg/g. According to these results, it can be concluded that straetlingite-based sorbents can be used for NH4+ ion removal from a synthetic aqueous solution, as well as for both NH4+ and P removal from industrial wastewater. In the wastewater, a significantly higher sorption capacity of the investigated sorbents was detected for P than for NH4+.

Plastic Waste Conversion over a Refinery Waste Catalyst.

Polypropylene (PP) makes up a large share of our plastic waste. We investigated the conversion of PP over the industrial Fluid Catalytic Cracking catalyst (FCC-cat) used to produce gasoline from crude oil fractions. We studied transport limitations arising from the larger size of polymers compared to the crude oil-based feedstock by testing the components of this catalyst separately. Infrared spectroscopy and confocal fluorescence microscopy revealed the role of the FCC matrix in aromatization, and the zeolite Y domains in coking. An equilibrium catalyst (ECAT), discarded during FCC operation as waste, produced the same aromatics content as a fresh FCC-cat, while coking decreased significantly, likely due to the reduced accessibility and activity of the zeolite domains and an enhanced cracking activity of the matrix due to metal deposits present in ECAT. This mechanistic understanding provides handles for further improving the catalyst composition towards higher aromatics selectivity.

Matrix Effects in a Fluid Catalytic Cracking Catalyst Particle: Influence on Structure, Acidity, and Accessibility.

Matrix effects in a fluid catalytic cracking (FCC) catalyst have been studied in terms of structure, accessibility, and acidity. An extensive characterization study into the structural and acidic properties of a FCC catalyst, its individual components (i.e., zeolite H-Y, binder (boehmite/silica) and kaolin clay), and two model FCC catalyst samples containing only two components (i.e., zeolite-binder and binder-clay) was performed at relevant conditions. This allowed the drawing of conclusions about the role of each individual component, describing their mutual physicochemical interactions, establishing structure-acidity relationships, and determining matrix effects in FCC catalyst materials. This has been made possible by using a wide variety of characterization techniques, including temperature-programmed desorption of ammonia, infrared spectroscopy in combination with CO as probe molecule, transmission electron microscopy, X-ray diffraction, Ar physisorption, and advanced nuclear magnetic resonance. By doing so it was, for example, revealed that a freshly prepared spray-dried FCC catalyst appears as a physical mixture of its individual components, but under typical riser reactor conditions, the interaction between zeolite H-Y and binder material is significant and mobile aluminum migrates and inserts from the binder into the defects of the zeolite framework, thereby creating additional Brønsted acid sites and restoring the framework structure.

Single Particle Assays to Determine Heterogeneities within Fluid Catalytic Cracking Catalysts.

Fluid catalytic cracking (FCC) is an important process in oil refinery industry to produce gasoline and propylene. Due to harsh reaction conditions, FCC catalysts are subject to deactivation through for example, metal accumulation and zeolite framework collapse. Here, we perform a screening of the influence of metal poisons on the acidity and accessibility of an industrial FCC catalyst material using laboratory-based single particle characterization that is, µ-XRF and fluorescence microscopy in combination with probe molecules. These methods have been performed on density-separated FCC catalyst fractions, allowing to determine interparticle heterogeneities in the catalyst under study. It was found that with increasing catalyst density and metal content, the acidity and accessibility of the catalyst particles decreased, while their distribution narrowed with catalyst age. For example, particles containing high Ni level possessed very low acidity and were hardly accessible by a Nile Blue dye. Single catalyst particle mapping identifies minority species like the presence of a phosphated zeolite ZSM-5-containing FCC additive for selective propylene formation, catalyst particles without any zeolite phase and catalyst particles, which act as a trap for SOx .

Octane isomer dynamics in H-ZSM-5 as a function of Si/Al ratio: a quasi-elastic neutron scattering study.

Dynamical behaviour of n-octane and 2,5-dimethylhexane in H-ZSM-5 zeolite catalysts of differing Si/Al ratios (15 and 140) was probed using quasi-elastic neutron scattering, to understand molecular shape and Brønsted acid site density effects on the behaviour of common species in the fluid catalytic cracking (FCC) process, where H-ZSM-5 is an additive catalyst. Between 300 and 400 K, n-octane displayed uniaxial rotation around its long axis. However, the population of mobile molecules was larger in H-ZSM-5(140), suggesting that the lower acid site concentration allows for more molecules to undergo rotation. The rotational diffusion coefficients were higher in H-ZSM-5(140), reflecting this increase in freedom. 2,5-dimethylhexane showed qualitative differences in behaviour to n-octane, with no full molecule rotation, probably due to steric hindrance in the constrictive channels. However, methyl group rotation in the static 2,5-dimethylhexane molecules was observed, with lower mobile fractions in H-ZSM-5(15), suggesting that this rotation is less hindered when fewer Brønsted sites are present. This was further illustrated by the lower activation barrier calculated for methyl rotation in H-ZSM-5(140). We highlight the significant immobilizing effect of isomeric branching in this important industrial catalyst and show how compositional changes of the zeolite can affect a range of dynamical behaviours of common FCC species upon adsorption. This article is part of a discussion meeting issue 'Science to enable the circular economy'.

Biogasoline production from linoleic acid via catalytic cracking over nickel and copper-doped ZSM-5 catalysts.

Catalytic cracking of vegetable oil mainly processed over zeolites, and among all the zeolites particularly HZMS-5 has been investigated on wide range for renewable and clean gasoline production from various plant oils. Despite the fact that HZSM-5 offers a higher conversion degree and boost aromatics yield, the isomerate yield reduces due to high cracking activity and shape selectivity of HZSM-5. Hence, to overcome these problems, in this study the transition metals, such as nickel and copper doped over HZSM-5 were tested for its efficiencies to improve the isoparaffin compounds. The catalysts were screened with linoleic acid in a catalytic cracking reaction conducted at 450 ᵒC for 90 min in an atmospheric condition in batch reactor. Then, the gasoline composition of the organic liquid product (OLP) was analysed in terms of paraffin, isoparaffin, olefin, naphthenes and aromatics (PIONA). The results showed that Cu/ZSM-5 produced the highest liquid yield of 79.1%, at the same time reduced the production of gas and coke to 18.8% and 0.7%. Furthermore, the desired isoparaffin composition in biogasoline increased from 1.6% to 6.8% and at the same time reduced the oxygenated and aromatic compounds to 15.4% and 59.7%, respectively. The linoleic acid as model compound of rubber seed oil, in the catalytic cracking reaction provides a clearer understanding of the process. Besides, the water gas shift (WGS) reaction in catalytic cracking reaction provides insitu hydrogen production to saturate the branched olefin into the desired isoparaffin and the aromatics into naphthenes.

Highly efficient catalytic pyrolysis of polyethylene waste to derive fuel products by novel polyoxometalate/kaolin composites.

We report here alumina-substituted Keggin tungstoborate/kaolin clay composite materials (KAB/kaolin) as polyethylene cracking catalysts. KAB/kaolin composites with varying concentrations of KAB (10-50 wt.%) were synthesized by the wet impregnation method and successfully characterized by Fourier-transform infrared spectroscopy, powder X-ray diffraction, thermo-gravimetric analysis and scanning electron microscopy with energy dispersive X-ray spectroscopy analytical techniques. Use of KAB loaded kaolin composites as the catalyst for low-density polyethylene (LDPE) cracking exhibited a higher percentage of polymer conversion (99%), producing 84 wt.% of fuel oil and negligible amount (˂ 1 wt.%) of solid residue while thermal cracking produced ~22 wt.% residue. Furthermore, gas chromatography-mass spectrometry analysis of oil obtained by non-catalytic cracking exhibited a high selectivity to high molecular weight hydrocarbons (C13-C23) compared to the catalytic cracking where 70 mol.% of gasoline range hydrocarbons (C5-C12) were produced. We propose that higher cracking ability of our prepared catalysts might ensue from both Brønsted and Lewis acid sites (from KAB and kaolin respectively), which enhanced the yield of liquid fuel products and reduced the cracking temperature of LDPE. These findings suggest that the prepared composites were cost-effective and excellent cracking catalysts that could be recommended for highly efficient conversion of waste plastic materials to petrochemicals at an industrial scale.

Nickel Poisoning of a Cracking Catalyst Unravelled by Single-Particle X-ray Fluorescence-Diffraction-Absorption Tomography.

Ni contamination from crude oil in the fluid catalytic cracking (FCC) process is one of the primary sources of catalyst deactivation, thereby promoting dehydrogenation-hydrogenation and speeding up coke growth. Herein, single-particle X-ray fluorescence, diffraction and absorption (µXRF-µXRD-µXAS) tomography is used in combination with confocal fluorescence microscopy (CFM) after thiophene staining to spatially resolve Ni interaction with catalyst components and study zeolite degradation, including the processes of dealumination and Brønsted acid sites distribution changes. The comparison between a Ni-lean particle, exposed to hydrotreated feedstock, and a Ni-rich one, exposed to non-hydrotreated feedstock, reveals a preferential interaction of Ni, found in co-localization with Fe, with the γ-Al2 O3 matrix, leading to the formation of spinel-type hotspots. Although both particles show similar surface zeolite degradation, the Ni-rich particle displays higher dealumination and a clear Brønsted acidity drop.

Synthesis of EU-1/ZSM-48 Co-Crystalline Zeolites from High-Silica EU-1 Seeds: Tailoring Phase Proportions and Promoting Long Crystalline-Phase Stability.

A facile, specific, seed-assisted strategy for the synthesis of EU-1/ZSM-48 co-crystalline zeolites in the presence of hexamethonium ions (HM2+ ) has been developed. EU-1/ZSM-48 co-crystalline zeolites with various phase proportions, with EU-1 in the range of 25 wt %-86 wt %, were obtained by adding high-silica EU-1 seeds (SiO2 /Al2 O3 ratio of 300) and adjusting the synthesis parameters. Not only can the phase proportions of EU-1/ZSM-48 co-crystalline zeolites be controlled, but also the stability period for co-crystallization of the two phases can be extended through varying the amount of EU-1 seeds and the HM2+ template. Moreover, with the increase of the EU-1 proportion in the EU-1/ZSM-48 co-crystalline, the framework SiO2 /Al2 O3 ratios of EU-1 phase promotes steadily. Major differences in acidity and textural properties of the EU-1/ZSM-48 co-crystalline zeolites (Coz) were found with varying phase proportions, due to their distinct topological structures, crystal morphology and asymmetry between the EU-1 and ZSM-48 phases. For instance, the EU-1/ZSM-48 zeolite containing 75 wt % of EU-1 (Coz-75) possesses specific acidity and mesoporous characteristics, showing an excellent catalytic activity and stability in n-hexane cracking reaction. Compared to EU-1, ZSM-48, and a mechanical mix of the two zeolites (Mix-75), Coz-75 resulted in the highest hexane conversion and yields of light olefins, with a propylene yield, in particular, up to 38.3 wt %, which is 6.3 % more than that of the Mix-75 sample.

Magnetophoretic Sorting of Single Catalyst Particles.

A better understanding of the deactivation processes taking place within solid catalysts is vital to design better ones. However, since inter-particle heterogeneities are more a rule than an exception, particle sorting is crucial to analyse single catalyst particles in detail. Microfluidics offers new possibilities to sort catalysts at the single particle level. Herein, we report a first-of-its-kind 3D printed magnetophoretic chip able to sort catalyst particles by their magnetic moment. Fluid catalytic cracking (FCC) particles were separated based on their Fe content. Magnetophoretic sorting shows that large Fe aggregates exist within 20 % of the FCC particles with the highest Fe content. The availability of Brønsted acid sites decreases with increasing Fe content. This work paves the way towards a high-throughput catalyst diagnostics platform to determine why specific catalyst particles perform better than others.

Densification of Silica Spheres: A New Pathway to Nano-Dimensioned Zeolite-Based Catalysts.

Nanosized materials are expected to play a unique role in the development of future catalytic processes. Herein, pre-prepared and geometrically well-defined amorphous silica spheres are densified into silica-rich zeolites with nanosized dimensions. After the densification, the obtained nanosized zeolites exhibit the same spherical morphology like the starting precursor but characterized by a drastically reduced size, higher density, and high crystallinity. The phase transformation into crystalline zeolite material and the densification effect are achieved through a well-controlled steam-assisted treatment of the larger precursor particles so that the transformation process proceeds always towards the center of the spheres, just like a shrinking process. Furthermore, this procedure is applicable also to commercially available silica particles, as well as aluminum-containing systems (precursors) leading to acidic nano-catalysts with improved catalytic performance.