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Wood of the Lead tree (Leucaena Leucocephala) is pyrolyzed in an Iwasaki kiln to produce charcoal with a graphitic-like structure with a surface area of 329 m2/g. The charcoal is ground into 3 different particle sizes (large, medium, and small) and activated with carbon dioxide to produce activated carbon. The structure, morphology, elemental composition, porosity, and functional groups of the activated carbon samples are compared with the charcoal precursor. The larger particle size of the charcoal gives activated carbon with a larger surface area, up to 609 m2/g. In addition, wood vinegar is collected during the pyrolysis at 3 temperature ranges and extracted by n-hexane, diethyl ether, and ethyl acetate. The compositions depend on the collecting temperature. The main components are ketones, organic acids, furan and pyran derivatives, esters, phenols and derivatives, alcohols, and alkanes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Phase formation of Cu 3 P during the reduction process was studied by in situ XRD and in situ XAS. • Deoxygenation of guaiacol using Cu 3 P supported on SiO 2 was demonstrated for the first time. • Guaiacol adsorption on the Cu 3 P surface was proposed by a combined DFT and experimental approach. In situ characterization has become indispensable technique in the heterogeneous catalyst development because it provides insights into the composition and fundamental nature of materials in a dynamic process. In this work, in situ analysis including X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD) could disclose phase transition via several intermediates during the reduction of copper phosphate precursor (CuHPO 4 ·H 2 O) to copper phosphide on high surface silica support (Cu 3 P/SiO 2). The synthesized Cu 3 P/SiO 2 was further used as a catalyst for hydrodeoxygenation (HDO) reaction of guaiacol, a well-known representative model compound in lignin-derivatives upgrading. Many major products, such as cyclic hydrocarbons, demethylated, deoxygenated, and methylated compounds, were detected in the reaction mixture. The highest selectivity of catechol (72 mol%) was obtained at reaction condition of 300 °C and 50 bar H 2 after 150 min. The density-functional theory (DFT) calculations revealed the local electronic charge nature and the different roles of Cu and P active sites towards the interaction between reactants/intermediates and the Cu 3 P surfaces. The findings of the phase transition during the Cu 3 P synthesis and its catalytic activity to the guaiacol HDO reaction, the first to be reported, is beneficial for improving the efficiency metal phosphide-based catalyst for lignin-derived bio-oil into biofuels in the future. [ABSTRACT FROM AUTHOR]

• Aminopropyl-grafted Silica gel was simply prepared with ultrasound assistance. • Textural properties of the grafted silica gel were better than that from conventional preparation. • The grafted silica gel samples are active in aldol condensation of furfural and acetone. • Selectivity to furfurylbutenone as a major product was comparable to previous studies. This work focuses on the development of a simple method to prepare heterogeneous catalysts with tunable basicity and stability for aldol condensation of furfural and acetone. Silica gel was grafted by aminopropyltriethoxysilane (APTES) with 20, 30, 40 and 50 wt. % of APTES using probe-type ultrasonicator with a power of 130 W and a frequency of 20 kHz. The grafted samples were studied by XRD, SEM, N 2 sorption, FTIR, XPS, CHN and TG analysis, and CO 2 -TPD. The sonication facilitated the bond formation between APTES and the silica gel with less pore blocking than the conventional grafting method. The basicity of the samples was tunable with the quantity of APTES loading. The grafted samples were active catalysts for aldol condensation between furfural and acetone at 60 °C. The catalyst with 30 wt. % APTES grafting (30APS-U) provided a nearly complete furfural conversion and high furfurylbutenone selectivity. The conversion and selectivity increased with time and reached the highest values at 24 h. Thus, the catalysts with tunable basicity prepared by ultrasound-assisted grafting of silica with various APTES amounts were effective in furfural valorization. [ABSTRACT FROM AUTHOR]

Zeolites in powder form have the potential to agglomerate, lowering access to active sites. Furthermore, a suspension of fine zeolite powder in liquid media is difficult to separate. Such drawbacks could be improved by dispersing zeolite crystals on support materials. This work demonstrates the dispersion of zeolite NaY crystals on bamboo wood by mixing the wood with zeolite gel before hydrothermal treatment. The syntheses were performed with acid-refluxed and non–refluxed wood. The phase of zeolites, particle distribution and morphology, zeolite content in the wood, and zeolite–wood interaction were investigated using X-ray diffraction, X-ray tomography, scanning electron microscopy, thermogravimetric analysis, nitrogen sorption analysis, and X-ray photoelectron spectroscopy. Higher zeolite content and better particle dispersion were obtained in the synthesis with the acid–refluxed wood. The composite of NaY on the acid-refluxed wood was demonstrated to be an effective adsorbent for Ni(II) ions in aqueous solutions, providing a higher adsorbed amount of Ni(II) per weight of NaY. [ABSTRACT FROM AUTHOR]

NaY was synthesized from fumed silica and further modified to form a composite with SBA-15. Textural properties and basicity of the composite NaY-SBA-15 were between those of the parent materials. Paraquat adsorption on NaY was 204.1 mg/g, higher than that on NaY synthesized with rice husk silica from the previous work. SBA-15 was a poor adsorbent for paraquat. Based on the weight of NaY, the adsorption capacity of analytical-grade paraquat on the NaY-SBA-15 composite was 241.5 mg/g-NaY. Moreover, the composite adsorbed blue dye from a commercial grade paraquat. Interaction between the NaY-SBA-15 and paraquat could be from C and N atoms in paraquat with oxygen atom on NaY-SBA-15. [ABSTRACT FROM AUTHOR]

[Display omitted] • The ratio of ethanol to water affected the morphology and particle size of SiO 2 @C. • Surface species of SiO 2 @C core–shell effected the adsorption mechanism. • The thymol adsorption on the carbon shell was physisorption confirmed by DFT. • Thymol-grafted SiO 2 @C had prolonged antibacterial activity against S. aureus. Porous silica (SiO 2) nanoparticles have been widely used as drug-delivery materials; however, it is difficult to control drug release at desirable rates when using only SiO 2. Thus, a facile synthesis of SiO 2 -carbon core–shell (SiO 2 @C) nanoparticles with tunable sizes and shapes for efficient controlled release was developed to prolong the antibacterial activity of thymol (T). The physicochemical properties, and surface bonding between thymol and the carbon shell were determined with XPS, NEXAFS, and DFT studies. An in vitro thymol release study was also applied, and the prolonged antibacterial performance was evaluated with gram-positive Staphylococcus aureus. The optimal conditions for producing spherical SiO 2 @C core–shell nanostructures with a uniform size distribution included an ethanol-to-water ratio of 20:80 (E20W80). This produced a SiO 2 @C core–shell material with a high porous carbon content and a large pore volume. Moreover, SiO 2 @C-T exhibited the highest thymol release profile. DFT studies demonstrated that the thymol was physically adsorbed on the carbon surface. This adsorption mode was advantageous for prolonged release. Consequently, the bacteriostatic agent SiO 2 @C-T E20W80 showed sustained thymol release levels of up to 40% over 48 h. The developed SiO 2 @C material shows potential for use as a nanocarrier of drug/active ingredients. [ABSTRACT FROM AUTHOR]

NaY samples in the crystalline form with Si/Al ratios from 2.15 to 2.40 were synthesized as adsorbents for paraquat. Their surface areas, particle size, concentration of basic sites decreased with an increase of Al content in the synthesis gel. The interaction between paraquat molecule and NaY zeolite was investigated by periodic DFT calculations to understand the adsorption behavior. Paraquat adsorption by all samples fit with Langmuir model. The capacity of the adsorbents was in the range of 210–240 mg/g-adsorbent, higher than NaY in the previous reports. After paraquat adsorption, the surface areas of the samples decreased from around 800 to 30 m2/g indicating that paraquat adsorbed inside the zeolite pores. FAU samples with the highest Si/Al ratio (2.40) had the highest adsorption capacity in line with the results from the DFT calculations. The paraquat molecules located close to the negatively charged fragments of the zeolite framework, due to the electrostatic interaction with the positively charged ammonia groups of the organic molecule. Image 1 • NaY zeolites with Si/Al ratios from 2.15 to 2.40 were synthesized. • The zeolites had paraquat adsorption capacity from 210 to 240 mg/g-adsorbent. • NaY zeolite with the highest crystallinity had the highest adsorption capacity. • Interaction between paraquat and the zeolite is investigated by DFT calculations. • Paraquat located close to the negatively charged of the zeolite framework. [ABSTRACT FROM AUTHOR]

• Combined experimental and DFT studies can elucidate the role of Pt catalyst. • Adding Pt atom into HY zeolite facilitates C‒C cleavage and formation processes. • The isomerization on Pt-HY catalyst required a remarkably low barrier of 0.97 eV. • The Pt-HY catalyst is more selective towards 2MP than 3MP. In this study, we used several in situ, and spectroscopy analyses to investigate the roles of platinum (Pt) in zeolite-supported Pt catalysts for selective n -alkane isomerization. HY zeolites were synthesized using the rice husk silica and impregnated with Pt precursor by incipient wetness impregnation. Typically, HY zeolites have proved to be active hydrocarbon cracking catalysts. The particular challenge is to find an effective catalyst, which favors the isomerization of n -alkanes without too much cracking. In this work, adding Pt atoms to HY zeolite provides an enhanced multifunctional catalyst for converting n -alkanes to branched hydrocarbons. To understand the effect of Pt, we further investigated the reaction mechanism of n -hexane isomerization to 2–methylpentane (2MP) and 3-methylpentane (3MP) by DFT simulations, using a cluster of 30T HY zeolite modeled through B3LYP + 3D calculations. We found that, at 450 °C, the isomerization on Pt-HY gives higher cracking products. Decreasing temperature to 300 °C yielded greater selectivity of branched hydrocarbons. In addition, DFT calculations demonstrate that the 2MP production via route A1 (C3-C4 bond activation) and a rate-determining step of 0.97 eV proved more thermodynamically and kinetically favorable than the 3MP product. This agrees well with our experimental observations. Consequently, the presence of Pt on the HY zeolite plays an essential role in both C C forming and breaking. Finally, the Pt–HY zeolite is an efficient catalyst for petroleum production, improving the octane number for catalytic performance and product selectivity by isomerizing straight-chain alkanes to their branched chain isomers. [ABSTRACT FROM AUTHOR]

SBA-15 is a stable mesoporous silica with a uniform pore structure but without active catalytic sites. The incorporation of aluminium (Al) into its structure could generate acid sites for catalysis. Here, we report a comparative study of Al-incorporated SBA-15 (Al-SBA-15) by one-pot hydrothermal method from sodium aluminate (SA), aluminium sulfate (AS), and aluminium isopropoxide (AI). All Al-SBA-15 samples have mesoporous characteristics with incorporated Al in the structure, generating acid sites. Despite the similar Si/Al ratios, their total acidities are different, ranging as follows: Al-SBA-15 (SA) < Al-SBA-15 (AS) < Al-SBA-15 (AI). In contrast, the ratio of Al in tetrahedral coordination within the SBA-15 framework (Al tet) increases in the opposite trend: Al-SBA-15 (SA) > Al-SBA-15 (AS) > Al-SBA-15 (AI). From catalytic testing, all samples provide better xylose conversions and furfural yields than the pristine SBA-15. The xylose conversions increase with the total acidity, however, the furfural yield depends on the relative ratios of Lewis to Brønsted acid sites. Moreover, lactic acid by-product increases with Al in octahedral coordination (Al oct). The best catalyst is Al-SBA-15 (SA), giving high furfural yield and the fewest by-products. Further investigations on Al-SBA-15 (SA) confirm that the optimum conditions are at 170 °C; for 5 h; and the catalyst loading of 0.10 g. [Display omitted] • Three Al sources are employed: NaAlO 2 (SA), Al 2 (SO 4) 3 (AS), and Al(O- i -Pr) 3 (AI). • Total acidity from NH 3 -TPD: Al-SBA-15 (SA) < Al-SBA-15 (AS) < Al-SBA-15 (AI). • Ratio of tetrahedral Al (Al tet): Al-SBA-15 (SA) > Al-SBA-15 (AS) > Al-SBA-15 (AI). • Xylose conversion increases with total acidity; furfural selectivity depends on Al tet. [ABSTRACT FROM AUTHOR]