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Abstract MoO 3 /SiO 2 catalysts were prepared by impregnation, co-precipitation and stepwise precipitation, respectively. Their textural structure and physicochemical properties were characterized by low temperature N 2 adsorption, SEM, TEM, and NH 3 -TPD technologies, and their catalytic activity was tested using the hydrodeoxygenation of guaiacol in an autoclave. SP-MoO 3 /SiO 2 catalyst prepared by stepwise precipitation exhibits the highest catalytic activity for conversion of guaiacol to aromatic hydrocarbons. Direct cleavage of the C-O bond by hydrolysis over oxygen vacancy of MoO 3-x is dominant during the HDO of guaiacol, leading to the high selectivity for arenes. In addition, large amount of toluene was found in the product over SP-MoO 3 /SiO 2 catalyst, suggesting that the methyl transfer reaction can be promoted by the strong acidity. [ABSTRACT FROM AUTHOR]

Abstract Direct conversion of lignocellulose to fuels has been widely considered as one of most potential ways to produce renewable transportation fuels. In current study, 70.6% yield of gasoline-range hydrocarbons (C 5 and C 6 alkanes) was directly obtained from cellulose by using Ru/C and boron phosphate in aqueous medium. For conversion of cellulose to hydrocarbon, the main intermediates were sorbitol and its dehydration products, such as 1,4-, 1,5-, 2,5-sorbitans and isosorbide. The formation of isosorbide was undesirable due to its bis-tetrahydrofuranic moieties which are resistant to further hydrogenolysis to hydrocarbon. In current catalysis system, boron phosphate played a positive effect on formation of dehydration products from sorbitol. The hydrolysis process of boron phosphate in solution would probably delay both of the arrival of H+ with substrate and the increase of acidity in solution, which might reduce the formation rate of isosorbide. In addition, the coordination of boric acid with polyhydroxy compounds could also bring a barrier to the cyclodehydration of sorbitol to isosorbide. Therefore, in the presence of boron phosphate, the production of liquid hydrocarbon from cellulose can be significantly improved. Furthermore, the reaction pathway of cellulose transformation to C 5 /C 6 alkanes via dehydration products of sorbitol was also proposed. [ABSTRACT FROM AUTHOR]

A pilot study on transformation of corn stover into bio-aviation fuel with low oxygen content of 0.4%, high heat value of 45.5 MJ/kg, and mass yield of 10.6% was achieved. [Display omitted] • Pilot study on transformation of corn stover into aviation fuel is achieved. • The operational processes include six units. • The aviation fuel has a high heat value of 45.5 MJ/kg, rich in isoparaffins. • The catalyst for hydrodeoxygenation and oil-upgrading lasted for 42 days. Aviation fuel is high energy density and is usually produced from refinery in petroleum industry. Production of renewable aviation fuel from biomass eases pressure of carbon emission regulation. The operational processes in this study include steam stripping, hydrolysis of residues, condensation reaction unit, autoclave hydrogenation, fixed-bed hydrodeoxygenation, and oil-upgrading unit. The biomass-derived aviation fuel has a low oxygen content of 0.4 %, while its high heat value is 45.5 MJ/kg. The aviation fuel ranges from C8 ∼ C15, and rich in isoparaffins (50.4 %) while the n -paraffins have a selectivity of 12.2 % and other components are cycloparaffins (19.0 %), aromatic hydrocarbons (11.3 %), and alkenes (5.6 %). The mass yield for aviation fuel from corn stover reaches 10.6 %. This pilot study achieved production of aviation fuel from raw biomass corn stover. [ABSTRACT FROM AUTHOR]

• A C20 oxygenate was synthesized from biomass-derived furfural and levulinic acid. • The yield of C20 oxygenate was up to 95%. • The C20 oxygenate was further hydrodeoxygenated to aviation turbine fuel using Pd/C + H 3 PO 4. • The oxygen content was decreased to 4.09 %, while the high heat value was increased to 47.04 MJ/kg. Catalytic conversion of biomass to liquid fuel is one of critical part to ease dependence on fossil fuel. Herein, a route of transformation of biomass-derived furfural and levulinic acid into long-chain hydrocarbon fuels was developed. A C20 oxygenate with 95 % mol yield was firstly synthesized through condensation-polymerization reactions catalyzed by NaOH. Various techniques were employed to verify the chemical structure of the C20 oxygenate. The condensation mixture was then directly subjected to hydrodeoxygenation reaction to prepare long-chain hydrocarbons with a catalytic system of Pd/C and H 3 PO 4 in aqueous phase. A 57.1 % weight yield of liquid fuel was obtained with main products of C12, C14, and C18 hydrocarbons. The mass percent of carbon and hydrogen in fuel was significant improved to 95.91 %, as well as the high heat value was increased to 47.04 MJ/kg. [ABSTRACT FROM AUTHOR]

The integrated 1000 tonne/a-scale bio-jet fuel-range hydrocarbon (C 8 -C 15 ) synthesis system via aqueous phase deconstruction and catalytic conversion process was analyzed for its techno-economics of biomass residue utilization. The operation characterization, mass flow and cost in the system were discussed. A two-step deconstruction of corncob, steam stripping and acidic hydrolysis, was designed for the production of the platform chemicals, furfural and levulinic acid from hemicellulose and cellulose respectively. The oxygenate intermediates with the increased carbon chain length was produced by alkali catalyzed aldol condensation from furfural and levulinic acid. The oxygenate intermediates were catalytically converted to jet fuel-range hydrocarbon (C 8 -C 15 ) by the tandem steps of low-temperature hydrogenation, high-temperature hydrodeoxygenation and upgrading over noble metal catalysts. The results indicated that bio-jet fuel yield is 139 kg/h or 8 tonne of dried corncob for 1 tonne fuel production. The operation cost of bio-jet fuel is about $1540/tonne and the cost on corncob, catalytic catalyst and H 2 contributed 23%, 19% and 16% respectively. The cost sensitivity analysis showed that the catalytic lifetime was one of the main factors that affected the economics of bio-jet fuel production, which could increase bio-jet fuel price to $1820/tonne when its lifetime was reduced to 0.5 year. [ABSTRACT FROM AUTHOR]

The demonstration operation of an pilot-scale bio-dimethyl ether(DME) synthesis system was carried out for with 300-350 kg/h of wood chips as feedstock. The tar content was 4.4-5.7 g/Nm 3 and carbon percent in the residual char was low due to the combined advantages of the specific gasifier combining with upstream and downstream gasification with O 2 -rich air(46.3vol%), fed through the top and bottom inlets of the gasifier. Steam, as the secondary gasifying agent, also increased H 2 content in the raw bio-syngas. The reforming of tar and light hydrocarbons further decreased tar content to 0.42-0.67 g/Nm 3 over Ni-MgO/γ-Al 2 O 3 cordierite monolithic catalysts with less than 5.0vol% of CH 4 content in the raw bio-syngas. CO 2 removal efficiency was about 70% by pressure-swing unit(PSA), using propylene carbonate as adsorbent. CO conversion and space-time yield of DME over Cu/Zn/Al/HZSM-5-packed fixed-bed tubular reactor were 61.4-71% and 90.4-155.8 kg/m cat 3 /h respectively when the gas hourly space velocity(GHSV) was 650-1500 h -1 at 220 o C and 4.3 MPa. The selectivity of methanol and hydrocarbons were than less 3% under the typical operation condition. About 15.7% carbon of dried wood chip was converted to DME with the production cost of ca. ¥4810/ton DME. [ABSTRACT FROM AUTHOR]

Gasoline production by one-pot catalytic conversion of biomass derived sugar/polyol was investigated over bifunctional heterogeneous catalyst. Ni@HZSM-5/SG catalyst showed excellent performance of converting sugar/polyol to gasoline. The gasoline yield of 46.94% was obtained. Its composition and properties are similar to petroleum based gasoline. It provides a novel approach for the production of gasoline by one-pot aqueous phase catalytic conversion of sugar/polyol derived from biomass. [ABSTRACT FROM AUTHOR]

Bimodal support modified Cu-Fe based catalysts with different pore structures were prepared and tested for higher alcohols synthesis (HAS). It was found that the bimodal derived catalyst showed both higher catalytic activity and selectivity of C 2 + OH compared to the traditional Cu-Fe based catalysts. In particular, both the activity and C 2 + OH selectivity presented an increasing trend with the gradual decrease in bimodal support pore sizes. The characterization results indicated that decreasing support pore sizes resulted in the increase of BET surface area and dispersion of active Cu and Fe species inside the pore structures, which increased the bimetallic active sites and strengthened probably the synergistic effect of Cu-Fe via “confine effect” of bimodal pore structures, improving the HAS catalytic activity and shifting product distribution towards higher alcohols. [ABSTRACT FROM AUTHOR]

Bio-oil can't be directly used as fuel due to its deteriorate properties. Here, an efficient catalytic upgrading process for the bio-oil, including esterification, hydrogenation, hydrodeoxygenation and depolymerization, is proposed with multifunctional catalyst Ni/SiO 2 –ZrO 2 and biomass-derived solvent ethanol. Results showed that esters, alcohols, phenolics, and cyclo-ketones were the main components in the upgraded bio-oil while aldehydes were removed completely via catalytic hydrogenation and acids were removed by catalytic esterification with supercritical ethanol. The pH value of upgraded bio-oil rose drastically from 2.38 to 5.24, and the high heating value increased to 24.4 MJ kg −1 . Comparison characterization on the upgraded and crude bio-oil using FT-IR, GPC (Gel permeation chromatography) and 13 C NMR (Nuclear Magnetic Resonance) demonstrated that lignin-derived oligomers contained in crude bio-oil were further depolymerized over Ni/SiO 2 –ZrO 2 catalyst. The improved properties suggest that the upgraded bio-oil is more suitable to be used as boiler fuel. Furthermore, the loss of carbon is negligible because formation of coke is suppressed during the upgrading process. [ABSTRACT FROM AUTHOR]

The high-quality bio-jet fuel derived from biomass resources can directly replace commercial fossil fuels for aviation due to the similar composition and properties. However, conventional technologies on hydrodeoxygenation of plant oil can’t produce renewable aromatics, which is the key component in the jet fuel. In this paper, the bio-jet fuels were produced by aqueous-phase processing of plant sugar/polyol. Liquid fuel yield of 31.8% with sorbitol conversion of 98% was obtained under the conditions of 280 °C, WHSV of 1.25 h −1 , GHSV of 2500 h −1 and 4.0 MPa hydrogen pressure. The content of aromatics and napthenes was above 72 wt.% in the produced liquid fuels. This process uses a wide variety of both cellulosic and conventional plant sugars, providing an economic route to sustainable bio-based jet fuel production, which includes normal and iso-paraffins, naphthenes, and aromatics required for aviation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Achieved 99.6% guaiacol conversion to hydrocarbon with a cost-effective Cu-ZnO-Al 2 O 3 catalyst. • Oxygen vacancies on ZnO/Cu surface boost guaiacol hydrodeoxygenation. • Density Functional Theory calculations reveal key catalytic pathways, providing crucial design insights. • Proven stability over seven cycles, emphasizing potential for industrial-scale biofuel production. This study explores the efficacy of a cost-effective Cu-ZnO-Al 2 O 3 catalyst for one-pot hydrodeoxygenation of guaiacol into hydrocarbons. Notably, complete conversion of guaiacol was achieved, yielding a 99.6% hydrocarbon over the robust Cu(6)Zn(3)Al(1) catalyst under the conditions of 4 MPa H 2 , 300 °C, and 8 h with a catalyst/guaiacol ratio of 0.5 g/1.0 g. In-depth catalyst characterizations unveiled the presence of oxygen vacancies within the ZnO surface layer, acting as pivotal active sites that facilitated the hydrodeoxygenation of guaiacol. Furthermore, Density Functional Theory (DFT) calculations were employed to evaluate several potential active sites, revealing that the oxygen vacancy of ZnO on the Cu surface played a crucial role. This vacancy enhanced the adsorption of intermediate cyclohexanol and markedly reduced the energy barrier for the rate-limiting step. This comprehensive investigation sheds light on the catalytic pathway and offers insights into designing efficient and sustainable biofuel production processes. [ABSTRACT FROM AUTHOR]

Abstract In this work, hierarchical ZSM-5 zeolites featured by different Si/Al ratio and mesoporosity were prepared via soft template. The hierarchical zeolites supported iron catalysts were prepared by incipient impregnation and their properties were studied by XRD, XRF, BET, SEM, TEM and NH 3 -TPD. The resultant catalysts were used to convert syngas into aromatics. The results indicated that zeolite with high acidity could increase the selectivity to aromatics in the oil product. By using low Si/Al ratio catalyst Fe-Z-50-5, 70.7% of selectivity to aromatics can be obtained in oil product. With the increase of mesoporosity, selectivity of C 5+ oil product also increased. By adjusting silane addition, 23.2% selectivity of aromatics was obtained in hydrocarbon over Fe-Z-80-15 catalyst, which is the highest among all the same catalyst system under low H 2 /CO syngas (H 2 /CO = 1). However, hierarchical zeolite support with different Si/Al ratio and mesoporosity have little effect on the distribution of aromatic product. [ABSTRACT FROM AUTHOR]

Highlights • Process design and techno-economics of pilot bio-jet fuel facility were studied. • Yields of furfural, LA, intermediate, bio-jet fuel were 59.5%, 34.4%, 75% and 51%. • 47.6% energy and 31% carbon of carbohydrate in corncob is recovered in bio-jet fuel. • TCP, OPEX and MSFB (no tax) was $3.96 MM, $1.18/L and $1.45/L for a 1.3 ML/a facility. • Economies of scale on MSFB is obvious when the discount rate increases and taxes impose. Abstract Process design and techno-economic analysis of a pilot bio-jet fuel production facility were investigated using Aspen plus software and net present value method (NPV). This process include two-step hydrothermal decomposition of corncob to furfural (steam stripping of hemicellulose) and Levulinic acid (LA, acidic hydrolysis of cellulose), oxygenated precursor production via aldol condensation reaction of furfural and LA, and the subsequent hydro-processing for oxygen removal. Lab experiments on the major area of the process were carried out. The yields of furfural, LA, oxygenated precursor and bio-jet fuel-range hydrocarbons (C 8 –C 15 ) were 59.5% (based on hemicellulose), 34.4% (based on cellulose), 75% (based on furfural and LA input) and 51 wt% (based on precursor) respectively. These values were used as the input information for the process simulation of a first-of-a-kind pilot facility for 1.3 ML/a bio-jet fuel production using this pioneering technology. The mass and energy analysis from Aspen plus model shows that the bio-jet fuel yield was 0.125 tonne/tonne dried corncob. 31.0% of carbon atoms and 47.6% of potential energy from carbohydrate compounds of corncob leave as bio-jet fuel. The estimated consumption of water, steam and electricity is relatively high of 12.3 kg, 63.7 kg and 1.22 KW h respectively due to small simulation scale and lack of process optimization. The total capital cost was ca. $3.96 MM for the 1.3 ML/a facility, of which 28% of equipment investment is spent for oxygenated precursor production. The total operation expense (OPEX) is $1.18/L bio-jet fuel, including variable and fixed costs. Expenses on corncob, catalytic catalyst and H 2 contribute 23%, 19% and 16% respectively. Single point sensitivity analysis of the major breakdown of OPEX shows that catalyst lifetime is the priority factor. Economy of scale of minimum selling price of bio-jet fuel (MSPB) for different capacity facilities (1.3 ML/a, 6.5 ML/a and 13 ML/a) was investigated using different discount and tax rates, of which the lowest MSPB was $0.74/L with a subsidy of $0.31/L at 10% discount rate. [ABSTRACT FROM AUTHOR]

[Display omitted] • A highly dispersed Fe/C catalyst was prepared using pomelo peel as carbon source. • Fe/C catalyst achieved an excellent STY in CO 2 hydrogenation to light olefins. • Metal-support interaction can be regulated by pyrolysis temperature. • Excellent performance is due to the rich functional groups, Fe 3 O 4 and Fe 5 C 2. Although considerable progress has been made in the hydrogenation of CO 2 to light olefins through the modified Fischer-Tropsch synthesis route (CO 2 -FTS), the design of catalysts with high selectivity and stability is still a challenge. Herein, a simple, highly dispersed and scalable Fe/C-400 catalyst was prepared by in-situ pyrolysis using pomelo peel (PP) as carbon source, and was first used in CO 2 hydrogenation to light olefins. This catalyst exhibited a high space time yield of light olefins (48.3 μmol CO2 ·g Fe −1·s−1), and the light olefins selectivity and O/P were 63.0% and 9.0, respectively. More surprisingly, no obvious deactivation was observed within 200 h. A series of characterization techniques such as TEM, TG-MS, FTIR, XPS, H 2 -TPR and 57Fe Mössbauer spectrum showed that the naturally abundant oxygen-containing functional groups in PP support could impart metal-support interactions that enhance the dispersion of iron species. The modulation of the catalyst phase composition was achieved by simply varying the residual amount of oxygen-containing functional groups to impart different metal-support interactions. The catalysts prepared at lower pyrolysis temperatures retained more oxygen-containing functional groups and therefore had stronger metal-support interactions, which facilitated the formation of more active phases. Overall, this newly developed catalyst realized the high activity and high stability production of CO 2 hydrogenation to light olefins, providing a cost-effective and sustainable way for its industrial application. [ABSTRACT FROM AUTHOR]

Direct production of 2,5-dimethylfuran (DMF) from fructose is crucial for developing biomass-derived fuels, yet it presents significant challenges due to the need for multifunctional active sites for dehydration and hydrodeoxygenation. Meanwhile, the disposal of wine lees, a major winemaking by-product, incurs substantial costs. Herein, a hybrid catalyst system of sulfonated wine lees carbon (WLC-SO 3 H) and PtFe/C was introduced, achieving a DMF yield of 66.4 % directly from fructose. WLC-SO 3 H, with enhanced Brønsted acidity, demonstrated high activity in dehydrating fructose to 5-hydroxymethylfurfural (HMF) with a 98.2 % yield. PtFe/C effectively catalyzed the hydrodeoxygenation of HMF to DMF, driven by the strong interaction between Pt and Fe species. This interaction was confirmed through in situ DRIFTS and theoretical calculations, highlighting the system's superior catalytic performance. [Display omitted] • A hybrid catalyst of sulfonated wine lees carbon and PtFe/C was developed. • The hybrid catalyst catalyzed fructose to a yield of 66.4 % 2,5-dimethylfuran. • Sulfonated wine lees carbon dehydrated fructose to 98.2 % 5-hydroxymethylfurfural. • Strong interaction in PtFe/C promoted hydrodeoxygenation of 5-hydroxymethylfurfural. • Utilized wine lees waste for sustainable waste valorization and biofuel production. [ABSTRACT FROM AUTHOR]

Acidic promoters are significant in the hydrodeoxygenation (HDO) of bioderived furans into alkanes over metal-acid bifunctional catalysts. Here, a supported Pd/HPW-SiO 2 catalyst was prepared to investigate the promotion effect of phosphotungstic acid (HPW) on the HDO of HMF-acetone adduct (H-Ac). Characterizations suggested that an intimate contact between Pd and HPW was established in Pd/HPW-SiO 2. HPW promoters significantly reduced the reduction temperature of Pd oxides with enhanced hydrogenation and HDO capability. Particularly, in-situ DRIFTS confirmed that Pd-HPW sites significantly weakened the π CO η 2 adsorption mode (ν 3 (C=O)) of C=O group on Pd surfaces. Thereby, the HDO efficiency was synergistically improved through releasing more Pd metal sites to activate hydrogen for hydrogenation and HDO with HPW promoters. Eventually, >90% yield of nonane was efficiently achieved at 160 °C. This work is applicable to explore the structure-activity relationship of bifunctional catalysts in the efficient HDO of complicated oxygenated bioderived furans. • More than 90 % yield of nonane was efficiently obtained from H-Ac at 160 °C. • HPW promoters facilitated Pd oxides to be reduced at 14–40 °C with enhanced hydrogenation and HDO capability. • Pd-HPW sites synergistically improved the HDO efficiency of C-O through weakening the π CO η 2 adsorption mode on Pd sites. [ABSTRACT FROM AUTHOR]

The development of thermally stable Pt-based catalysts with superior performance for propane dehydrogenation reactions remains a daunting challenge. In this study, a series of PtSn-Mg(Zn)AlO catalysts with different Zn and Pt contents were synthesized by the anion-exchange method for the propane dehydrogenation reaction. To investigate the influence of Zn on the reaction performance and the catalyst structure, the prepared catalysts were characterized with several analytical techniques, including XRD, TEM, HRTEM, H 2 -TPD and CO pulse chemisorption. A good propane conversion (initially higher than 55% and averaging 45.2% over a period of 2 h) and propene selectivity (higher than 99%) were obtained experimentally with PtSn-Mg(3Zn)AlO at 550 °C. The results demonstrated that Pt provided the active sites and that Zn was a promoter. The HRTEM and CO pulse chemisorption results indicated that the addition of Zn to the PtSn-MgAlO catalyst can stabilize the dispersion of metal particles and thus inhibit the sintering of Pt particles. Furthermore, the activities of the used catalysts were almost recovered through reaction-regeneration cycles with the burning-off of coke during five cycles. • Zn influences the structure and properties of PtSn-MgAlO. • An average propane conversion of 45.2% for a period of 2 h was obtained. • Propene was obtained with a superior selectivity of above 99%. • Propane conversions still attain 38.5% after 5 reaction–regeneration cycles. [ABSTRACT FROM AUTHOR]

Selective hydrogenation of unsaturated-organic compounds derived from biomass sources is a key step for producing chemicals and fuels, but it faces challenges in enhancing product selectivity and energy efficiency. Metal nanoparticles (NPs) encapsulated in zeolite crystals (metal@zeolite) are desirable and robust materials that can control catalytic activity and selectivity by tuning their structure. However, the solvent effect on selective hydrogenation over metal@zeolite has been unexplored, which plays a significant role in the reaction process. Here, the solvent effect on the selective hydrogenation of cinnamaldehyde (CAL), a representative substrate, over Pd–Ni bimetallic clusters encapsulated inside S-1 zeolite (Pd0.6Ni@S-1) was first reported. The results showed that Pd0.6Ni@S-1 effectively converted CAL into hydrocinnamaldehyde (HCAL) under mild conditions and that the product distribution was solvent-dependent by correlating the selectivity with solvent properties. The polarity of polar solvents affected the solvent-CAL interaction and thus the hydrogenation pathway. Our study reveals the importance of solvent engineering for selective hydrogenation over metal@zeolite catalysts and provides insights for designing efficient and robust materials for biomass conversion. [Display omitted] • Pd0.6Ni@S-1 showed high activity and selectivity for the selective hydrogenation of CAL to HCAL under mild conditions. • The hydrogenation of the C O bond of HCAL was difficult, and the main by-product HCOL was derived from COL. • Conversion and selectivity were controlled by steric effect and polarity of solvent. • Solvent engineering was a key factor in optimizing the performance of metal@zeolite catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • ZSM-5 zeolites with similar acidity but different mesoporosity and mesoporous sizes can be synthesized. • Increased zeolitic mesoporosity can improve stability of iron-based/ZSM-5 catalyst by inhibiting coke. • Decreased zeolitic mesoporous size can increase the aromatics selectivity and light aromatics fraction. The utilization of iron-based/ZSM-5 bifunctional catalysts for converting syngas to aromatics (STA) has garnered significant interest because of its cost-effectiveness. This study aims to elucidate the regulatory mechanism of zeolitic pore structure on the performance of the bifunctional catalyst in STA reaction. The relationship among the mesoporosity and mesoporous diameter of hierarchical ZSM-5 zeolite component, product distribution, and catalyst stability is investigated through a range of analyses techniques, including XRD, SEM, TG, Raman, N 2 -adsorption and desorption. The results demonstrate that as the mesoporosity of zeolite increased to 78.9%, the lifetime of the iron-based/ZSM-5 bifunctional catalyst extended beyond 96 h and maintained the aromatics selectivity over 40% at 2 MPa, 320 °C, and 3000 h−1. This outcome can be attributed to the role of high mesoporosity in restraining coke formation in zeolites. Moreover, the reduction in mesopore size from 11.1 to 5.8 nm results in an increased aromatics selectivity from 39.6% to 43.4%, and the fraction of light aromatics rose from 48.8% to 54.5%, indicating that small mesopore size can also expedite the production of aromatics, particularly light aromatics. It is thus concluded that the improvement of aromatics selectivity and stability of iron-based/ZSM-5 bifunctional catalysts in STA reaction can be achieved by increasing the mesoporosity and decreasing the mesopore size of the zeolite component. [ABSTRACT FROM AUTHOR]

Selective hydrogenation of alkynes is a challenging reaction that requires selective and efficient catalysts to achieve the desired alkenes. The development of general and robust catalysts that can operate under mild conditions and tolerate a wide range of functional groups is still an active area of research. Here, Pd-M bimetallic clusters (M = Ni, Cu, Mn, Fe) encapsulated inside S-1 zeolite were prepared and applied in the selective hydrogenation of substituted terminal alkynes. Among them, the Pd0.6Ni@S-1 catalyst displayed 91 % selectivity to styrene at the full conversion of phenylacetylene. Derivatives of phenylacetylene containing either electron withdrawing/donating or sensitive functional groups were effectively converted into the corresponding alkenes. The confinement effect of zeolite effectively inhibited the over-hydrogenation reaction and enhanced the stability of the catalysts. Furthermore, the product distribution was solvent-dependent by correlating the reaction selectivity with solvent properties. Apolar solvent showed the highest selectivity to styrene in the selective hydrogenation of phenylacetylene due to the competitive adsorption of apolar solvent and styrene on catalysts. [Display omitted] • Pd0.6Ni@S-1: Selective and stable for the selective hydrogenation of terminal alkynes. • The zeolite confinement effect inhibited over-hydrogenation and stabilized metal species. • Solvent affected product distribution, apolar solvents favor styrene formation. • The study reveals solvent effect and metal-zeolite interactions in alkyne hydrogenation. [ABSTRACT FROM AUTHOR]

Renewable lipids can be converted into jet fuel-range alkanes via catalytic hydrotreatment, and many researches have been conducted over the past few decades. Relevant specification for Hydroprocessed Esters and Fatty Acids Synthetic Paraffinic Kerosene (HEFA-SPK) has been approved by American Society of Testing Materials (ASTM), and lipids-derived aviation fuel has been used in the commercial flights because of its obvious advantages in the reduction of carbon dioxide emissions. This paper introduces production processes for sustainable aviation fuels by hydroprocessing of lipids. First, the properties of lipids and their pretreatment methods are introduced. Hydrotreating catalysts, including supported single/bimetallic catalysts, metal sulfide catalysts, metal oxide catalysts, metal carbide and nitride catalysts, are introduced by category, and their catalytic mechanism in the hydroprocessing of lipids is discussed. In addition, several major commercial production technologies and techno-economic evaluations for the production of bio-aviation fuel from lipids are introduced. Finally, major challenges and promising prospects are also pointed out for the future development of conversion of lipids to aviation fuels. HEFA-SPK (Hydroprocessed Esters and Fatty Acids Synthetic Paraffinic Kerosene) is an important type of sustainable aviation fuel (SAF) produced from lipids. This work carefully reviewed and summarized the properties of lipid feedstocks and pretreatment, hydrotreating catalysts, production processes and techno-economic evaluation. [Display omitted] • The properties of lipids and its pretreatment methods were introduced. • Hydrotreating catalysts of lipids were summarized by category. • Deoxygenation routes (HDO, DCN or DCX) of triglyceride depend on catalyst and reaction conditions. • Major commercial production technologies of jet fuel from lipids were introduced. [ABSTRACT FROM AUTHOR]

[Display omitted] • The metal was successfully loaded on Ti-MOF using the static method. • Noble metals could fine-tune the valence band of photo-catalysts. • Ti-MOF/Pt is an excellent photocatalyst for co-production of H 2 and DFF. • Production ratio reach as high as 727 and 558 μmolh−1g−1, respectively. • This reaction system is universal. Photocatalytic H 2 evolution and selective oxidation of Hydroxymethylfurfura (HMF) occur in synergy, which improves the utilization of photogenerated carriers. In this paper, Ti-MOFs with noble metal (NM) co-doping was used in the H 2 evolution and HMF oxidation to prepare a highly efficient photocatalyst. Under visible light irradiation, the formation rate of H 2 and 2,5-dicarbonylfuran (DFF) was significantly increased by 4.03 times and 4.65 times compared with the original Ti-MOF. In this process, the separation of photoexcited electrons (e−) and holes (h+) is promoted and both e− and h+ are effectively utilized. From the density functional theory (DFT) calculations and XPS spectra results, it can be seen that the e− generated by the photoexcitation of Ti-MOF will transfer spontaneously to Pt, promoting the utilization of e−. The catalysts are effect for different biomass substrates as well. This work improves separation of the photo-induced carriers and enhances the oxidation ability by adjusting the valence band of metal loading, providing a new research direction for the evolution H 2 in the conversion of HMF to DFF. [ABSTRACT FROM AUTHOR]

Heavy fraction of bio-oil, the bottom-layer of biomass fast pyrolysis oil, is hard to be directly used due to its high molecular weight, complex components and deteriorate thermal stability. Here, a novel catalytic hydrotreating process for the heavy fraction of bio-oil, including depolymerization, decarboxylation, decarbonylation, hydrogenation and hydrodeoxygenation (HDO), is proposed with Ru/α-Al 2 O 3 catalyst and super/subcritical ethanol. Results demonstrated that heavy fraction of bio-oil was depolymerized into monomeric phenolic compounds, and then was converted to hydrocarbons by hydrodeoxygenation in one-pot. The average molecular weight (M w ) of upgraded oil decreased drastically from 8941 g/mol to 937 g/mol during the catalytic hydrotreating process, and the formation of coke is suppressed. Under the optimal conditions, the total yield of hydrocarbons, which were comprised of alkyl-substituted cyclohexane and alkyl-substituted benzene, could be up to 23.15%. These hydrocarbons have a high octane number, would be the desirable components for fungible liquid transportation fuel. Furthermore, Ru/α-Al 2 O 3 catalyst can be regenerated by calcination in the presence of O 2 . These results indicated high quality fuels could be obtained from heavy fraction of bio-oil over suitable catalytic system. [ABSTRACT FROM AUTHOR]

• The Pd-Ni oxide nanoclusters within S-1 exhibited excellent activity for nitrile base-free hydrogenation. • The yield of benzylamine achieved 92% with a TON of 1667. • Upscaling reaction of 500 mg benzonitrile also gave a benzylamine yield of 92%. • The key success factor was the cooperative interaction of bimetallic Pd-Ni species. The selective hydrogenation of nitrile represents an atom-economical and reliable method to synthesize primary amine, a privileged compound in chemistry, biology, and medicine. However, this approach often displays severe selectivity issues, and additives or reducing agents are generally required to solve this problem. In this work, we aim to synthesize primary amine on a green catalytic system and probe into the catalytic mechanism of Pd-Ni interaction using benzonitrile (BN) as a model compound. The nitrile hydrogenation reaction was catalyzed by bimetallic Pd-Ni oxide nanospecies confined in Silicalite‑1 (S-1) zeolite using H 2 as hydrogen donor without any additive which was environmentally friendly and economic. A 92% yield of benzylamine (BA) was achieved on the Pd0.6Ni@S-1 catalyst with a turnover number (TON) of 1667, and such BA yield was still maintained in upscaling experiment. Detailed characterizations shed light on the mechanism of the extraordinary performance of Pd-Ni oxide nanospecies on base-free nitrile hydrogenation. [ABSTRACT FROM AUTHOR]