We synthesized zeolite-templated carbons (ZTCs) using BEA@silicalite-1 core–shell zeolite scaffolds and investigated how the surface chemistry and framework architecture affects CO₂-adsorption performance. The silicalite-1 coating, which was applied using a steam-assisted crystallization process, effectively lowered aluminum exposure on the external surface of the beta-type zeolite (BEA) while preserving its microporous network. The resulting ZTCs displayed exceptionally high surface areas (>2200m²/g), narrow pore-size distributions centered at around 0.9nm, and superior structural order, as evidenced by Raman spectroscopy and XPS. CO₂-adsorption experiments performed in the 279–315K range revealed high capacities of up to 19.5mmol/g (86wt%) at 14bar, and complete process reversibility over multiple cycles. The isosteric heats of adsorption (≈17–22kJ/mol) confirmed that a physisorption mechanism operates, thereby ensuring a low regeneration energies and stable performance. Overall, the introduction of a silicalite-1 shell enables fine-tuning of the carbon structure and surface functionalities without sacrificing porosity, and provides an effective strategy for engineering next-generation ZTCs for use in efficient and sustainable CO₂-capture applications.

This study explores the hydrogen and methane adsorption properties of beta-zeolite-templated carbons (beta-ZTCs). It evaluates the effects of chemical and thermal post-synthesis treatments on their structural, textural, and surface functionalities. Modifications to surface oxygen functionalities led to slight changes in carbonyl, lactone, and phenol species, alongside a minor reduction in long-range pore order. Despite these alterations, the microporous nature of beta-ZTCs remained dominant, with minimal impact on H(2 )adsorption at 77 K. The materials demonstrated high storage capacities, achieving 6.4 wt% for H(2 )and 18.7 wt% for CH4, with volumetric uptakes of 40 g/L (H-2, 77 K, 40 bar) and 110 g/L (CH4, 298 K, 50 bar), comparable to compressed gas systems. The results highlight that the treatments had a limited effect on pore surface structure and microporosity (similar to 90 % of total pore volume), significantly contributing to enhanced gas uptake. At room temperature, beta-ZTCs exhibited a strong affinity for CH(4 )over H-2, with adsorption ratios nearing 10 across the pressure range, underscoring their potential for gas separation. These results highlight the suitability of beta-ZTCs for sustainable energy storage and separation technologies, with the post-synthesis treatments providing insights into performance tunability.

Zeolite-Template-Carbon is a new class of porous ordered carbon-based materials synthetized using 3-D zeolites as a template, then for these features have been investigated CO2 capture. This work presents the synthesis and characterization of ZTC on beta-type zeolite with a tuning-surface properties procedure resulting from different post-synthesis strategies aimed to tune the surface O-containing functional groups. It shows how a suitable micropore size distribution, a high specific surface area and a pore wall functionalization could maximize the reversible CO2 adsorption. Structural, chemical and morphological characterization has been obtained by X-ray diffraction, Thermo-gravimetric analysis, Raman/FT-IR spectroscopy, Branauer-Emmett-Teller analysis and scanning electron microscopy, while adsorption properties were investigated with Sievert's-type apparatus. XRD patters showed good replica of 3-D zeolite frameworks without presence of graphene and FT-IR spectroscopy indicated the presence of different carbon-oxygen functional groups. Adsorption measurements, at room tem-perature and pressure range 0-15 bar, showed a reversible CO2 uptake of 76.5 wt%. Furthermore, using deconvolution approach, a deep Raman spectroscopy analysis allowed us to assess the change in the structural order and in oxygen atomic coordination induced by post-synthesis treatment in correlation with the adsorption capacity. Post-synthesis treatments induced structure modification elucidated by evidence of an increased order of the porous structure and variation of the amorphous carbon fraction.

Zeolite Templated Carbons (ZTCs) are a class of materials that feature the textural properties of the template zeolites and the high conductivity of graphene-like structures. These characteristics make ZTCs a valuable candidate for CO2 catalytic reduction. We report here for the first time that metal-free ZTCs obtained from Beta zeolite are a novel valuable energy material for the reduction of CO2 to formic acid, about 10 times better than a reference reduced graphene oxide catalyst. In addition, it is evidenced that the pristine ZTC contains a large amount of oxygen, an aspect largely underestimated in literature. A specific method to reduce this oxygen content was developed, that coupled to an in-depth characterization by multiple techniques of these materials, allows to understand the nature of the oxygen functionalities on ZTCs surface. Moreover, it was evidenced that the change of oxygenated species by combined thermal and NaBH4 treatment of ZTCs affects the catalytic behavior, leading to a remarkable increase in the performances compared to the pristine one. The comparison of the performances and characteristics of two ZTCs, obtained by different BEA nanostructures, allow to correlate better the modification of the type of oxygen species present in ZTCs to the catalytic behavior. The results open new perspectives for the catalytic application of deoxygenated ZTCs. (C) 2022 Elsevier Ltd. All rights reserved.

Catalytic pyrolysis of plastic wastes is a promising way for their conversion into valuable products. By modu-lating the catalyst properties and operating conditions, it is possible to direct the product distribution to obtain oils that may be suitable both as fuels and as chemicals. However, the efficient and safe removal of the halogens, often contained in plastic wastes, remains as a great challenge. In this work, the catalytic behaviour of ZSM-5 zeolites in the pyrolysis of a real chlorinated plastic waste of the electric and electronic equipment sector (WEEE), consisting of PE with about 3.4% of PVC, was investigated. To that end, three zeolite samples with different acidity and accessibility were synthesized and assayed. A thermal pre-treatment was applied to the plastic waste at 350 degrees C, which allowed a chlorine removal of 87% from the WEEE feedstock. The pyrolysis tests were carried out in a downdraft fixed-bed stainless steel reactor, with a catalyst/feedstock ratio of 0.2, at temperatures of 600 degrees C and 450 degrees C in the thermal and catalytic zones, respectively, of the reaction system. In comparison with thermal pyrolysis, that mainly produced waxes, the product distribution changed considerably by contacting the pyrolysis vapours with ZSM-5 zeolites, leading to a strong enhancement in the yield of oil and gases. The largest yield of oil (about 60 wt%), having a concentration of monoaromatics (mainly BTX) above 50 wt%, was attained over the desilicated ZSM-5 sample. Regarding chlorine distribution, about 90% was accu-mulated in the char fraction, probably captured by the inorganic components present in the raw WEEE waste. Coke was the second fraction in terms of Cl concentration, followed by wax and oil, whereas this halogen was almost not detected in the gases. The lowest concentration of Cl in the oil was attained with the desilicated zeolite, with a value below 90 ppm, which could facilitate the subsequent processing of this stream in refinery units.

Methanol (MeOH) dehydration for Dimethyl ether (DME) production is one of the possible pathways to produce a green, synthetic fuel that can substitute fossil/conventional ones in automotive/transportation applications. DME synthesis in gas phase usually occurs in presence of an acid catalyst at moderate temperature (up to 250 °C). This work deals with the use of MFI-type zeolitic catalysts. H form and desilicated zeolite samples were synthesized, characterized, and tested to investigate their catalytic activity in MeOH dehydration reaction. Ammonia temperature-programmed desorption (NH3-TPD) and Fourier-transform Infrared spectroscopy (FT-IR) analyses were carried out to elucidate the amount and the nature of acid sites. Zeolite sample desilicated for 60 minutes presented a higher amount of Bronsted acid sites (that can be correlated to the superior catalytic activity), while the Turnover frequency (TOF) referred to the amount of Bronsted acid sites is very similar for the investigated samples. Finally, preliminary kinetic investigation via linear fitting of experimental data on the Arrhenius plot was carried out for simple first and second order kinetic models.

The direct synthesis of H2O2 on Pd-based catalysts, although recognized as a potential route for the sustainable production of H2O2, is still limited by the low catalytic selectivity and safety concerns. Here, the calcination treatment effect, with the dispersion of Pd NPs and its interaction with Al2O3, is investigated. Catalysts have been prepared by the sol-immobilization procedure (SI) on Al2O3 as asymmetric alumina membranes (AAS) and tested in both reduced and calcined form (450°C, 1°C/min, 8 h) for the direct synthesis of H2O2. Finally, the catalytic performance was compared with other catalysts, prepared by hydrazine-reduction (NRC) and impregnation-decomposition (IDC) already reported in a previous paper and calcined for a shorter time (450°C, 1°C/min, 6 h).TEM micrographs showed the formation of Pd NPs with average diameters of 12 (NR), 3.8 (IDC), and 3.3 nm (SI), respectively. The reduced SI catalyst has shown a 2-4% selectivity. However, after calcination (SIC), a 69 % selectivity to H2O2 was reached. Compared with NRC and IDC catalysts, the selectivity increased within the series NRC IDC > SIC. The SIC catalyst's improved performance was related to the increased interaction with the support, stabilizing Pd in its oxidized form.

Phenol is a major component in the scrubber wastewater used for syngas purification in biomass-based gasification plants. Adsorption is a common strategy for wastewater purification, and carbon materials, such as activated carbons and biochar, may be used for its remediation. In this work, we compare the adsorption behavior towards phenol of two biochar samples, produced by pyrolysis and gasification of lignocellulose biomass, with two commercial activated carbons. Obtained data were also used to assess the effect of textural properties (i.e., surface area) on phenol removal. Continuous tests in lab-scale columns were also carried out and the obtained data were processed with literature models in order to obtain design parameters for scale-up. Results clearly indicate the superiority of activated carbons due to the higher pore volume, although biomass-derived char may be more suitable from an economic and environmental point of view. The phenol adsorption capacity increases from about 65 m/g for gasification biochar to about 270 mg/g for the commercial activated carbon. Correspondingly, service time of commercial activated carbons was found to be about six times higher than that of gasification biochar. Finally, results indicate that phenol may be used as a model for characterizing the adsorption capacity of the investigated carbon materials, but in the case of real waste water the carbon usage rate should be considered at least 1.5 times higher than that calculated for phenol.

Furfural is a platform bio-molecule for which is valuable to develop new green upgrading processes in biorefinery. We report here for the first time the high performance of Au/ZTC catalyst for the selective oxidation of furfural to 2-furoic acid, as first step to develop electrodes. The ordered nanostructure and high surface area of BEA structure replica ZTC allows to develop 3D-type electrodes. Au/ZTC catalyst shows higher performance than commercial Vulcan, used as reference conductive carbon in fuel cells. The weak acidity on ZTC avoids decarboxylation and esterification reactions, leading to about 90% of furfural conversion fully selectivity to 2-furoic acid.

Furfural is a platform bio-molecule for which is valuable to develop new green upgrading processes in biorefinery. We report here for the first time the high performance of Au/ZTC catalyst for the selective oxidation of furfural to 2-furoic acid, as first step to develop electrodes. The ordered nanostructure and high surface area of BEA structure replica ZTC allows to develop 3D-type electrodes. Au/ZTC catalyst shows higher performance than commercial Vulcan, used as reference conductive carbon in fuel cells. The weak acidity on ZTC avoids decarboxylation and esterification reactions, leading to about 90% of furfural conversion fully selectivity to 2-furoic acid.