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The catalytic conversion of CO2 into methane (CH4) offers a sustainable solution to the worsening global warming scenario, especially for controlling CO2 levels. This study reports silicalite-1 supported Ni catalysts with different loadings for CO2 conversion to CH4, prepared via wet impregnation. The X-ray diffraction pattern revealed an increase in crystallite size at higher Ni loadings, which was further supported by N2 sorption, where the specific surface area and microporosity of the catalysts were decreased. There was a slight shift in the reducibility of the catalysts, potentially indicating the impact of loading on dispersion and spatial distribution. The catalyst performance was evaluated over a range of temperatures at 5 bar and a GHSV of 20,000 mL gcat−1 h−1. Surprisingly, the Ni(5)@Silicalite-1 exhibited higher CO2 conversion efficiency across the range of temperatures compared to Ni(10)@Silicalite-1. The NiO(5)@Silicalite-1 demonstrated a maximum CO2 conversion of 88% at 450 °C, which was approximately 14% higher than that of the catalyst with a 10 wt.% loading. Notably, the CH4 selectivity pattern was quite identical across the catalysts, underscoring that the reaction pathways were unaffected by the loadings. The higher performance of NiO(5)@Silicalite-1 could be ascribed to smaller NiO crystallites and improved textural properties.

In this work the activity of ruthenium decorated carbon foam (Ru/CF) catalyst was studied in three phase hydrogenation reaction of d-xylose to d-xylitol. The developed catalyst was characterized by using scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, inductively coupled plasma optical emission spectrometry and nitrogen adsorption–desorption measurement. Kinetic measurements were carried out in a laboratory scale pressurized reactor (Parr®) assisted by SpinChem® rotating bed reactor (SRBR), at pre-defined conditions (40–60 bar H2 and 100–120 °C). The study on the influence of reaction conditions showed that the conversion rate and selectivity of hydrogenation reaction of d-xylose was significantly affected by temperature. These results have been proved by a competitive kinetics model which was found to describe the behavior of the novel system (Ru/CF catalyst used together with the SRBR) very well. Besides, it was revealed that the catalytic activity as well as the stability of our Ru/CF-SRBR is comparable with the commercial ruthenium decorated carbon catalyst (Ru/AC) under identical reaction conditions. Moreover, all steps from catalyst preparation and catalyst recycling as well as catalytic testing can be performed in an easy, fast and elegant manner without any loss of materials. Briefly, the developed Ru/CF catalyst used together with the SRBR could be used an excellent alternative for the conventional Raney nickel catalyst in a slurry batch reactor and offers an attractive concept with obvious industrial applicability.

An efficient photocatalyst consisting of CdS nanoparticle dispersed mesoporous silica-titania was prepared using amphiphilic triblock copolymer P123 as template and silica-titania sol-gel precursors. The CdS nanoparticle was incorporated into silica-titania mesoporous nanosturctures by post impregnation method. The synthesized catalyst has been characterized by FTIR, TEM, SEM, and EDAX analysis. The CdS nanoparticles incorporated silica-titania mesoporous particles exhibited an enhanced light harvesting, large surface area and excellent photocatalytic activity. Photocatalytic degradation experiments on methyleneblue solution at different pH of the medium revealed that, the catalyst ST0.5CdS0.2 is more effective in basic medium with a degradation efficiency of 98%. In addition, the catalyst is also tested for dye degradation against a raw textile dye effluent containing multiple dye molecules, and their results indicated that the raw effluent can be decolorized within 90min using ST0.5CdS0.2 catalyst.

Pd and PdAu catalysts supported on SBA15 and SiO2 were prepared and investigated for H2O2 direct synthesis in a batch autoclave (10 °C and 17.5 bar) and in the absence of halides and acids. The SiO2 supported catalysts exhibited inferior performances compared to the mesoporous ordered SBA15. A good control of both the catalysts dispersion and nanoparticle stability was achieved using SBA15. Catalysts were doped with bromine, a promoter in the H2O2 direct synthesis. Productivity and selectivity decreased when bromine was incorporated in the catalysts, thus indicating a possible poisoning due to the grafting process. A synergetic effect between Pd and Au was observed both in presence and absence of bromopropylsilane grafting on the catalyst surface. Three modifiers of the SBA15 support (Al, CeO2 and Ti) were chosen to elucidate the influence of the surface properties on metal dispersion and catalytic performance. Higher productivity and selectivity were achieved incorporating Al into the SBA15 framework, whereas neither Ti nor CeO2 improved H2O2 yields. The enhanced performance observed for the Prau/Al–SBA15 catalysts was attributed to the increased number of Brønsted acid sites. A modification of this catalyst with bromine was confirmed to impair both productivity and selectivity, possibly due to the broader particle size distribution and the poor stability of the metal nanoparticles, as demonstrate by transmission electron microscopy (TEM) images. H2O2 disproportionation was also investigated. A much slower reaction rate was observed compared to the H2O2 production, suggesting that the major contributor in the process of H2O2 destruction must be connected to the hydrogenation reaction.

The catalytic conversion of CO[sub.2] into methane (CH[sub.4]) offers a sustainable solution to the worsening global warming scenario, especially for controlling CO[sub.2] levels. This study reports silicalite-1 supported Ni catalysts with different loadings for CO[sub.2] conversion to CH[sub.4], prepared via wet impregnation. The X-ray diffraction pattern revealed an increase in crystallite size at higher Ni loadings, which was further supported by N[sub.2] sorption, where the specific surface area and microporosity of the catalysts were decreased. There was a slight shift in the reducibility of the catalysts, potentially indicating the impact of loading on dispersion and spatial distribution. The catalyst performance was evaluated over a range of temperatures at 5 bar and a GHSV of 20,000 mL g[sub.cat] [sup.−1] h[sup.−1]. Surprisingly, the Ni(5)@Silicalite-1 exhibited higher CO[sub.2] conversion efficiency across the range of temperatures compared to Ni(10)@Silicalite-1. The NiO(5)@Silicalite-1 demonstrated a maximum CO[sub.2] conversion of 88% at 450 °C, which was approximately 14% higher than that of the catalyst with a 10 wt.% loading. Notably, the CH[sub.4] selectivity pattern was quite identical across the catalysts, underscoring that the reaction pathways were unaffected by the loadings. The higher performance of NiO(5)@Silicalite-1 could be ascribed to smaller NiO crystallites and improved textural properties.

The present study introduces kinetic modeling of liquid phase α-pinene acetoxylation with acetic acid over an ion-exchange resin catalyst. The reaction was carried out in a laboratory scale high-pressure autoclave. α-terpinyl (35 wt%) and bornyl (40 wt%) acetates were the primary products. The predominant reaction pathways were identified and evaluated.

The catalytic conversion of CO into methane (CH ) offers a sustainable solution to the worsening global warming scenario, especially for controlling CO levels. This study reports silicalite-1 supported Ni catalysts with different loadings for CO conversion to CH , prepared via wet impregnation. The X-ray diffraction pattern revealed an increase in crystallite size at higher Ni loadings, which was further supported by N sorption, where the specific surface area and microporosity of the catalysts were decreased. There was a slight shift in the reducibility of the catalysts, potentially indicating the impact of loading on dispersion and spatial distribution. The catalyst performance was evaluated over a range of temperatures at 5 bar and a GHSV of 20,000 mL g h . Surprisingly, the Ni(5)@Silicalite-1 exhibited higher CO conversion efficiency across the range of temperatures compared to Ni(10)@Silicalite-1. The NiO(5)@Silicalite-1 demonstrated a maximum CO conversion of 88% at 450 °C, which was approximately 14% higher than that of the catalyst with a 10 wt.% loading. Notably, the CH selectivity pattern was quite identical across the catalysts, underscoring that the reaction pathways were unaffected by the loadings. The higher performance of NiO(5)@Silicalite-1 could be ascribed to smaller NiO crystallites and improved textural properties.

Catalytic conversion of carbon dioxide (CO 2 ) into useful chemicals such as methane (CH 4 ) is a promising carbon utilization method that effectively mitigates CO 2 and partially meets energy needs. The characteristics of commonly used nickel (Ni) supported meso/microporous catalysts for CO 2 methanation can be tailored by tuning the structural properties of the support and adding promoters. This work investigated the Ni supported over hierarchical zeolite 13X (h13X) and incorporated with different promoters (Mg, Ca, Ce, and La) developed using the wet‐impregnation method. The catalysts were thoroughly characterized using SEM, EDS, XRD, H 2 ‐TPR, CO 2 ‐TPD, thermogravimetric analysis (TGA), X‐ray photoelectron spectroscopy (XPS), and N 2 sorption and desorption techniques and evaluated for CO 2 methanation. The impact of promoters on the characteristics of the catalysts was observed with improved surface basicity in CO 2 ‐TPD and metal‐support interaction in H 2 ‐TPR analysis. Among the promoted catalysts, the NiLa/h13X catalyst exhibited the highest catalytic activity with a maximum conversion of 76% and CH 4 selectivity of 98.5% at 400°C and 20 bar at GHSV of 60,000 mL g cat −1 h −1 , respectively. Regarding stability, the Mg‐promoted catalyst exhibited better stability during 24 h of reaction than other catalysts, demonstrating better resilience against deactivation. The enhanced performance of the NiLa/h13X catalyst could be credited to the increased surface basicity, high surface area, and dispersion. This study highlights the potential of hierarchical porous zeolites for CO 2 methanation and other heterogeneous reactions.

In this study, we report a 3D structured carbon foam electrode assembled from a bi-functional NiCo catalyst, carbon nanotubes (CNT), and a monolith 3D structured carbon foam (CF) as a highly active and stable electrode for oxygen evolution reaction (OER) and methanol oxidation reaction (MOR). When the NiCo@CNTs/CF electrode was used as an anode in OER, after the anodization step, the electrode required a small overpotential of 320 mV to reach the current density of 10 mA cm−2 and demonstrated excellent stability over a long testing time (total 30 h) in 1 M KOH. The as-prepared NiCo@CNTs/CF electrode also exhibited a good performance towards methanol oxidation reaction (MOR) with high current density, 100 mA cm−2 at 0.6 V vs. Ag/AgCl, and good stability in 1 M KOH plus 0.5 M CH3OH electrolyte. The NiCo@CNTs/CF catalyst/electrode provides a potential for application as an anode in water electrolysis and direct methanol fuel cells.

In the present work electrically conductive, flexible, lightweight carbon sponge materials derived from open-pore structure melamine foams are studied and explored. Hydrophobic and hydrophilic surface properties - depending on the chosen treatment conditions - allow the separation and storage of liquid chemical compounds. Activation of the carbonaceous structures substantially increases the specific surface area from ~4 m 2 g −1 to ~345 m 2 g −1 , while retaining the original three-dimensional, open-pore structure suitable for hosting, for example, Ni catalyst nanoparticles. In turn the structure is rendered suitable for hydrogenating acetone to 2-propanol and methyl isobutyl ketone as well for growing hierarchical carbon nanotube structures used as electric double-layer capacitor electrodes with specific capacitance of ~40 F/g. Mechanical stress-strain analysis indicates the materials are super-compressible (>70% volume reduction) and viscoelastic with excellent damping behavior (loss of 0.69 ± 0.07), while piezoresistive measurements show very high gauge factors (from ~20 to 50) over a large range of deformations. The cost-effective, robust and scalable synthesis - in conjunction with their fascinating multifunctional utility - makes the demonstrated carbon foams remarkable competitors with other three-dimensional carbon materials typically based on pyrolyzed biopolymers or on covalently bonded graphene and carbon nanotube frameworks.