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[Display omitted] • Charcoal is produced from Lead tree wood in Iwasaki kiln (IW) and tube furnace (TF). • Activated carbon (AC) from both charcoals are used as supports for nickel phosphides. • AC_IW has higher C/O ratio than AC_TF. • Nickel phosphides disperse on external surface and macropores of AC_IW. • NiP/AC_IW gave green diesel yield more than three times higher than NiP/AC_TF. Carbon-oxygen ratios (C/O) in activated carbon (AC) derived from wood are usually dependent upon carbonization conditions. Such a ratio directly correlates with the hydrophobicity and hydrophilicity of AC. In this work, we use two different types of AC, which are prepared by carbonization of Lead tree wood charcoal in a tube furnace (AC_TF) and Iwasaki kiln (AC_IW), as a support for nickel phosphide (NiP) for catalytic hydrodeoxygenation (HDO) of palm oil to produce green diesel. Basically, AC_IW has a higher C/O ratio than that of AC_TF. This makes the surface of AC_IW more hydrophobic. Both AC_IW and AC_TF have a great influence on the dispersion and the acid property of Ni 2 P. The Ni 2 P nanoparticles disperse mainly outside the micropores of AC_IW, whereas those on AC_TF mainly appear inside the micropores. Interestingly, NiP/AC_IW outperforms NiP/AC_TF in HDO, with an impressive green diesel yield of 98.3 %, more than three times higher than that from NiP/AC_TF. The superior HDO performance of NiP/AC_IW could be attributed to the eased accessibility of reactants to the active sites. This obtained catalyst could have high potential application in an industrial scale due to the facile preparation method, low-cost materials, large-scale production, super catalytic activity. [ABSTRACT FROM AUTHOR]

• Synthesis of grafted and co-condensated ordered mesoporous materials. • Quantification of the amount of active base sites by liquid phase NMR. • Variation of the properties of the basic centre by changing the substitution on the nitrogen atom. • Determination of the turn-over number in the aldol condensation of butyraldehyde. • Proposed reaction mechanism for heterogeneously catalysed aldol condensation. Representative ordered mesoporous silica materials MCM-41 and SBA-15 were synthesized and modified with nitrogen-containing groups by grafting and co-condensation. The created catalytic centers strongly differ in basicity depending on the degree of substitution of the nitrogen atom. Furthermore, the introduced amount also depends on the structure of the modifier as shown by quantitative liquid phase 1H NMR. This allowed to calculate the turnover number in the aldol condensation of n -butanal which changed in the sequence: secondary > primary >> tertiary >> pyridinic basic centers. Corresponding reaction mechanisms considering the special structural features of the modifier are proposed. ig. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Unsupported Ni, Co, and Cu phosphides catalysts were prepared by precipitation method. • Ni 2 P + Ni 12 P 5 (Ni x P y), Co 2 P, and Cu 3 P phases were obtained after reduction in H 2. • Green diesel (GD) yield was in the order of Ni x P y > Co 2 P > Cu 3 P. • The major products were straight-chain alkanes with C 15 -C 18 from all catalysts. • The Ni x P y gave better the hydrodeoxygenation products than the commercial Ni 2 P. This work aims to investigate the catalytic hydrodeoxygenation (HDO) of palm oil to produce green diesel (GD) on phosphides of nickel (Ni), cobalt (Co), and copper (Cu) without support materials. The metal phosphides were obtained by co-precipitation of metal precursors and phosphoric acid followed by calcination and reduction with hydrogen. The as-synthesized, calcined and reduced samples were characterized by various modes of X-ray absorption spectroscopy (XAS) including time-resolved X-ray absorption (TR-XAS), X-ray absorption near edge structure (XANES), extended X-ray absorption fine structure (EXAFS), and X-ray diffraction (XRD). The phosphide phases of Ni, Co and Cu after reduction were mixed-phase Ni 2 P and Ni 12 P 5 (denoted as Ni x P y), Co 2 P and Cu 3 P, respectively. Their catalytic performance was determined in a continuous fixed-bed flow reactor under H 2 atmosphere at 300, 350 and 400 °C for 6 h. The best catalyst was Ni x P y providing the highest GD yields. The main catalytic route was decarbonylation (DCO) yielding C 15 + C 17. The minor routes were decarboxylation (DCO 2) and HDO. Moreover, Ni x P y provided better yields of all products than the commercial single-phase Ni 2 P. [ABSTRACT FROM AUTHOR]

The heterogeneous base catalysts were developed from zeolite-geopolymer hybrid material (Zeo-Geo) as a new support for potassium in transesterification of soybean oil. Zeo-Geo was prepared by mixing Al metal, metakaolin, and fumed silica in NaOH solution and curing at 60 °C, 24 h and 110 °C, 12 h. The Zeo-Geo contained a mixed phase of geopolymer and X-type zeolite. The xK/Zeo-Geo with x = 5, 10 or 15 wt% potassium were prepared by impregnation of Zeo-Geo with potassium acetate followed by calcination at 400 °C for 3 h. The phases of potassium were mainly K 2 O and K 2 CO 3 and the basicity increased with potassium loading. The 15K/Zeo-Geo was the most active catalyst in transesterification of soybean oil with methanol, at 70 °C providing 97.64% biodiesel yield under the optimum condition: reaction time = 3 h, methanol to oil molar ratio = 16:1 and catalyst amount = 2 wt%. The catalyst was reused in 5 cycles without a significant activity loss and leaching of active species. From this study, 15K/Zeo-Geo has a potential for further development in large-scale production. [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]

• Hierarchical NaY is synthesized from cogon grass silica with treated in NaOH. • Coexisted meso and micro-structure in hierarchical NaY is confirmed by N 2 sorption. • Removal efficiency of acid blue 185 is improved by hierarchical structure. • Interactions between acid blue 185 and hierarchical NaY are confirmed by XPS. • Hierarchical NaY preserves original removal efficiency, up to five cycles. Facile preparation of hierarchical structure NaY zeolite from cogon grass silica is synthesized by microwave-assisted hydrothermal method and subsequently desilicated in ultrasonic-assisted alkaline treatment. This work aims to improve the removal efficiency of acid blue-185 (AB-185) by using hierarchical NaY zeolite. When treated the parent NaY in NaOH solution with various concentrations (0.1, 0.5 and 1.0 M), the Si/Al ratios and micropore surface area decrease but increase a maximum pore size distribution of mesopore with the NaOH concentration due to the desilication effect. Moreover, the mesopore surface area and volume significantly increase and reach to the maximum value with a concentration of 0.5 M (132 m2 g−1 and 0.12 cm3 g−1). Consequently, the NaY (0.5 M) gives the highest percentage of AB-185 removal (80 ± 1.2 %) at a pH of 5 owing to the abundant adsorption sites and the eased accessibility of dye molecules. The adsorption data fit well with the Langmuir isotherm rather than Freundlich isotherm models with a correlation coefficient of 0.99. Maximum adsorption capacity of AB-185 on NaY (0.5 M) is larger than that on the parent NaY (84.5 mg/g vs 19.4 mg/g). In addition, the adsorption process of AB-185 on NaY (0.5 M) is more favorable by the pseudo-second-order kinetic model indicating the main rate-control is chemisorption. The existence of interactions between AB-185 and the NaY (0.5 M) is confirmed by FTIR and XPS. The reusability of the NaY (0.5 M) preserves original adsorption capacity, up to five cycles indicating a promising adsorbent for water treatment. [ABSTRACT FROM AUTHOR]

Palm oil is largely produced in Thailand and sufficient to utilize as a biofuel feedstock through hydrodeoxygenation (HDO). In this work a new bifunctional catalyst consisting of nickel phosphide supported on zeolite mordenite in sodium form (Ni-P/NaMOR) was prepared by sequential impregnation and characterized extensively by several techniques to understand the reduction behavior, phases and distribution of nickel phosphides on the support. Nickel and phosphate precursors were transformed to Ni 2 P 2 O 7 species by calcination and to a mixed phase between Ni 12 P 5 and Ni 2 P by reduction. The phosphide species distributed in the zeolite cavities and external surface. The HDO of palm oil was tested in a down-flow stainless steel trickle bed reactor and the atmosphere was hydrogen. The mixed phase of nickel phosphides enhanced the HDO reaction. When tested by various temperatures and pressures, the optimum condition in this work was at 425 °C and 50 bar in which a complete of palm oil conversion, the largest HDO yield and selectivity toward C 15 -C 18 alkanes were obtained. The green diesel and HDO yields from reduced Ni-P/NaMOR were larger than those from pure Ni 2 P and mixed Ni 2 P-Ni 12 P 5. Interestingly, a small amount of isoparaffins was also observed likely due to the contribution of NaMOR support. Unlabelled Image • Nickel phosphide on NaMOR was tested in hydrodeoxygenation (HDO) of palm oil. • The catalyst contained a mixed phase between Ni 12 P 5 and Ni 2 P with bifunctionality. • The mixed phosphide phase gave high yield and selectivity toward C 15 -C 18 alkanes. • The NaMOR support contributed a formation of isoparaffins. • The optimum condition to yield the largest HDO was at 425 °C and 50 bar. [ABSTRACT FROM AUTHOR]

Zeolite NaX was synthesized by using rice husk silica and used as a catalyst support. It was impregnated with potassium acetate buffer solution to produce xK/NaX where x was potassium loading of 4, 8, 12 and 16 wt.%. After calcination the zeolite characteristic in all catalysts were still observed. The surface area and micropore volume decreased with potassium loading indicating that the cavities were occupied. The potassium precursor was mainly converted to carbonate which had strong basicity. As the basicity increased with the potassium loading, the bettter catalytic performance in transesterification of Jatropha seed oil to biodiesel was observed. The best catalyst was 16K/NaX which gave 95.2 ± 0.96% biodiesel yield. [ABSTRACT FROM AUTHOR]

The goal of this work was to characterize active species in potassium catalysts supported on zeolite NaY prepared by ultrasound-assisted impregnation with acetate buffer (K/NaY-U). A catalyst from conventional impregnation (K/NaY) was also prepared for comparison. The potassium precursor from acetate buffer solution decomposed at 370–480 °C and converted to potassium carbonate as realized by several techniques. Both K/NaY-U and K/NaY contained moderate and strong basic sites. The K/NaY-U had a better dispersion of potassium species. Compared to K/NaY in a catalytic transesterification of palm oil, the reaction over K/NaY-U was faster and the biodiesel yield 72% was obtained in 2 h. The longer reaction time increased the yield slightly but not preferred in terms of energy consumption. The amount of potassium before and after catalytic testing was similar. [ABSTRACT FROM AUTHOR]

An ethanol steam reforming (ESR) reaction is a H 2 -production process that the fuel reacts with water in the presence of catalysts. The catalyst structures and active phase compositions have a role in ethanol conversion and hydrogen-production selectivity. The Fe 3 O 4 catalysts with Ni and Cr dopants were prepared and used for the ESR. The morphology and structural property of prepared catalysts were determined by FESEM-EDS, XRD, and XAS techniques. The spinel structures were observed in Fe 3 O 4 , Ni/Cr@Fe 3 O 4, and NiFe 2 O 4 while the CrFe 2 O 4 exhibited a mixture between Fe 2 O 3 and Cr 2 O 3 phases. The combined X-ray absorption spectroscopy, mass spectrometry, and gas chromatography was applied to investigate the performance of prepared catalysts during temperature-programmed reduction and ESR processes. The NiFe 2 O 4 exhibited the highest catalytic activity and stability for hydrogen production. The Ni-incorporation in spinel ferrite structure enhanced reduction efficiency of iron compounds at low temperatures and improves its catalytic activity and stability to the ESR process. Furthermore, the NiFe 2 O 4 catalyst also exhibited the ability to regenerate during ESR process as evidenced by X-ray absorption spectrum. • Improving of reduction behaviour of spinel Fe 3 O 4 by Ni addition was investigated by in situ XAS. • Operando XAS-GC-MS method was applied to investigate the performance of catalyst during ESR process. • The spinel NiFe 2 O 4 exhibited high stable, selective to H 2 -production and able to regenerate during ESR process. • The structural stability of Fe-species on the spinel catalysts played an important role to the ESR selectivity. [ABSTRACT FROM AUTHOR]