Converting biolipids into branched alkanes via direct deoxygenation and isomerization is an effective route to produce clean fuels. Here, a bifunctional MoS2/SAPO-11 catalyst was prepared under in situ sulfidation conditions using sulfur powder. The 10% MoO3-loaded catalyst achieved >99% conversion of methyl palmitate (MP) and raw palm oil (8 MPa H-2, and 380 degrees C), affording >70% liquid yield and a product freezing point of -14 degrees C. Comprehensive characterizations revealed that in situ-generated MoS2 is highly dispersed on SAPO-11 (<3 layers, <3 nm slab length). This performance originates from the MoS2-acid synergy: MoS2 deoxygenates MP to n-C-15/n-C-16 via HDO/HDCO2/HDCO pathways; the resulting linear alkanes undergo dehydrogenation over MoS2 and subsequent isomerization at acid sites to form long-chain branched alkanes, with acid-catalyzed cracking yielding short-chain branched hydrocarbons. Recycling tests confirmed stable HDO activity, whereas the reduced branching distribution arose mainly from structural degradation of SAPO-11. This study provides a promising strategy for designing bifunctional catalysts toward the direct upgrading of biolipids into high-quality, low-freezing-point liquid fuels.

Precisely controlling the hydrotreating reaction pathway of fatty acid methyl esters (FAMEs) to achieve value-added chemicals remains a significant challenge. This work reports a ZnO decoration strategy to modify the structure of MoS2/ZrO2 catalyst, and thereby tuning the hydrogenation reaction pathway of FAMEs. It is found that the introduction of ZnO modulates the electron cloud density of edge S vacancies on MoS2. The ZnO-decorated catalyst necessitates a higher temperature for the activation and dissociation of H2 at the edge sites of MoS2, while also weakens the adsorption of FAMEs, thereby enabling the regulation of the hydrogenation depth over MoS2. As a result, the reaction pathway of FAMEs is changed from hydrodeoxygenation (HDO) to selective hydrogenation, with fatty alcohols as the major products. At 260 ℃, 5MPa H2, and 2h, the conversion of methyl myristate (MM) reaches 90.7% with a tetradecanol yield of 73.9% on ZnO-decorated catalyst. Based on the product distributions, the hydrogenation mechanism was analyzed in details, and the corresponding kinetic parameters were obtained.

Gamma-Aluminum oxide (gamma-A2O3) is a promising catalyst for producing linear long-chain alpha-olefins via dehydration of biomass-derived n-alcohols but suffers from hydration-induced phase transformation and deactivation. Herein, the concept of M4+ incorporated octahedral cationic vacancies to boost activity and structure stability was established, particularly for Zr4+. Extended X-ray absorption fine structure and density functional theory (DFT) analyses reveal that Zr preferentially occupies octahedral sites, leading to hydroxyl consumption, formation of Zr-O-Al bonds, and lattice expansion due to the large ionic radius of Zr4+. Zr incorporation increases surface acidity owing to its electron-deficient state. Under optimized conditions, the catalyst achieves 100% conversion and 96.4% selectivity toward C-1(6) alpha-olefins. In-situ FTIR elucidates the dehydration pathway and reaction mechanism. The modified catalyst exhibits excellent stability for over 375 h, attributed to reduced surface hydrophilicity and strengthened Al-O bonds that suppress hydration-induced phase transition and carbon deposition.

In the slurry-phase hydroconversion to produce biofuels, the reaction mechanism for hydrodeoxygenation of long-chain unsaturated olefinic acids is still unclear. Here, MoS2 was in-situ generated during reaction using molybdenum(IV) 2-ethylhexanoate as the oil-soluble precursor. The generated MoS2 was identified with 1 T (or 1 T') phase rather than 2H phase based on Raman and EXAFS analysis. It is found that the hydrogenation of monounsaturated bonds firstly takes place, followed by the hydroconversion of carbonyl groups. Wax esters are then produced as the heavy by-products with up to similar to 69.3 % yield at 290 degrees C, however, it can be quickly consumed above 310 degrees C. Based on the in-situ FTIR and DFT results, the consumption of acids and formation of wax esters was distinctly illustrated. The C-O bond of the monodentate ester-type acid dissociates to form acyl group, which is then hydrogenated to form alkoxide, and they are finally combined to generate wax esters.

Efficient capture of residual NH3 from Haber-Bosch recycling gas is essential to improve process efficiency and reduce environmental impact. In this study, a series of sulfonated porous organic polymers (PTO-1S, PTT-1S, PTF-1S) were fabricated by a post-sulfonation strategy using phenolic hydroxyl-containing precursors to capture NH3. Comprehensive characterizations of the sulfonated derivatives demonstrated not only the successful grafting of -SO3H groups, but more importantly, a cooperative effect with the native phenolic -OH groups. The optimized PTO-1S achieves an outstanding NH3 capacity of 11.52 mmol/g (at 298.2 K and 1 bar), with particularly impressive performance at low pressures (5.56 mmol/g at 313.2 K and 0.03 bar), surpassing most reported adsorbents. Mechanistic studies revealed that this cooperation creates an optimal balance of strong chemisorption (-SO3H) and reversible hydrogen bonding (-OH), which is identified as the origin of the high capacity and exceptional cycling stability (< 1% capacity loss/cycle). Besides, the sulfonated samples maintain excellent selectivity under simulated industrial conditions (NH3/N-2/H-2 mixtures) and a rapid adsorption rate (90% saturation within 2 min), demonstrating their potential for practical NH3 recovery applications.

The development of efficient and stable solid acid catalysts for methyl esterification of long-chain fatty acids is of significant importance. Herein, a series of hydrophobic mesoporous sulfonated polymers (PDVB-SO3H-x) were synthesized via the solvothermal polymerization of divinylbenzene (DVB), followed by post-synthetic sulfonation with ClSO3H. The optimized catalyst, PDVB-SO3H-0.4, possesses rich mesoporosity (average pore size: 10.2 nm), and maintains surface hydrophobicity (water contact angle: 115.8 degrees). These properties are crucial for achieving high conversion (>93%) of various long-chain fatty acids under mild conditions (338.2 K and 240 min). Notably, PDVB-SO3H-0.4 exhibits superior intrinsic activity with a turnover frequency (TOF) of 172.6 h(-1) for palmitic acid conversion, significantly outperforming many reported solid acids. The catalyst demonstrates good recyclability, retaining 82.6% of conversion after 15 cycles with minimal structural degradation. A kinetic and thermodynamic study, corroborated by DFT calculations, provides deep insights into the methyl esterification of long-chain fatty acids with PDVB-SO3H-x catalysts. This work presents a class of highly active and stable mesoporous solid acid catalysts, highlighting the synergistic role of mesoporosity and hydrophobicity in enhancing esterification performance.

Polyaromatic hydrogenation is a key process for effectively utilizing the ∼1.5 billion tons of liquid fuels. However, this process faces a trade-off between catalyst activity and stability. Herein, we address this challenges through edge engineering of ultrasmall MoSx nanosheets from well-designed ionic liquid (IL) precursors. The unique cation-anion pairs endow ILs with high oil solubility and thermal stability, enabling the in situ synthesis of MoSx nanosheets with one to three layers, lateral sizes of 3–6 nm, and readily cleavable edges with abundant Co sites and S vacancies. These features regulate the electronic structure of MoSx and enhance the catalytic hydrogenation of polyaromatics, affording 99.9 mol % of phenanthrene (PHE) conversion and 82.0 mol % of perhydrophenanthrene (PHP) selectivity. The turnover frequency (TOF) for PHE conversion reaches 59.1 h−1 at 380°C, ranking this catalyst among the best reported for non-precious metals. Co-doped MoSx catalysts also show high stability and can be recycled without obvious deactivation.

Efficient capture of residual NH₃ from Haber-Bosch recycling gas is essential to improve process efficiency and reduce environmental impact. In this study, a series of sulfonated porous organic polymers (PTO1S, PTT1S, PTF1S) were fabricated by a post-sulfonation strategy using phenolic hydroxyl-containing precursors to capture NH3. Comprehensive characterizations of the sulfonated derivatives demonstrated not only the successful grafting of –SO₃H groups, but more importantly, a cooperative effect with the native phenolic –OH groups. The optimized PTO-1S achieves an outstanding NH₃ capacity of 11.52 mmol/g (at 298.2 K and 1 bar), with particularly impressive performance at low pressures (5.56 mmol/g at 313.2 K and 0.03 bar), surpassing most reported adsorbents. Mechanistic studies revealed that this cooperation creates an optimal balance of strong chemisorption (–SO₃H) and reversible hydrogen bonding (–OH), which is identified as the origin of the high capacity and exceptional cycling stability (< 1% capacity loss/cycle). Besides, the sulfonated samples maintain excellent selectivity under simulated industrial conditions (NH₃/N₂/H₂ mixtures) and a rapid adsorption rate (90% saturation within 2 min), demonstrating their potential for practical NH₃ recovery applications.

This work elucidates the structure-property relationships of alkylamine hydrochloride-based deep eutectic solvents (DESs) for efficient NH3 capture from industrial gas streams. Through systematic variation of hydrogen bond acceptors (HBAs) including amine type (primary/secondary/tertiary) and alkyl chain length (C-1-C-3). Three key structural parameters governing absorption performance: (1) amine substitution state (primary > secondary > tertiary), (2) alkyl chain length (C-1 > C-2 > C-3), and (3) HBA: HBD molar ratio (1:7 > 1:5 > 1:3 > 1:2). Primary amine-based DESs achieve optimal performance, exhibiting exceptional NH3 capacities (8.32 mol/kg at 313.2 K, 101.4 kPa) coupled with low viscosities (9.6-13.9 mPa & centerdot;s). Spectroscopic and computational studies reveal a cooperative dual-site absorption mechanism involving both phenolic -OH and ammonium protons of alkylamine hydrochlorides. The optimized solvents display outstanding NH3/CO2 selectivity (>170) and cycling stability (>88% retention after 5 cycles) compared to many reported absorbents, while comprehensive physicochemical characterization provides critical data for industrial implementation, such as viscosity, density, and thermal stability. These findings establish molecular design principles for NH3 capture solvents that simultaneously address capacity, selectivity, and transport property requirements.

AbstractEfficient recognition and selective capture of NH3 is not only beneficial for increasing the productivity of the synthetic NH3 industry but also for reducing air pollution. For this purpose, a group of deep eutectic solvents (DESs) consisting of glycolic acid (GA) and phenol (PhOH) with low viscosities and multiple active sites was rationally designed in this work. Experimental results show that the GA + PhOH DESs display extremely fast NH3 absorption rates (within 51 s for equilibrium) and high NH3 solubility. At 313.2 K, the NH3 absorption capacities of GA + PhOH (1:1) reach 6.75 mol/kg (at 10.7 kPa) and 14.72 mol/kg (at 201.0 kPa). The NH3 solubility of GA + PhOH DESs at low pressures were minimally changed after more than 100 days of air exposure. In addition, the NH3 solubility of GA + PhOH DESs remain highly stable in 10 consecutive absorption‐desorption cycles. More importantly, NH3 can be selectively captured by GA + PhOH DESs from NH3/CO2/N2 and NH3/N2/H2 mixtures. 1H‐NMR, Fourier transform infrared and theoretical calculations were performed to reveal the intrinsic mechanism for the efficient recognition of NH3 by GA + PhOH DESs.

Developing catalysts enabling reactive separation is a promising strategy to enhance reaction and separation efficiency of esterification processes. Herein, we designed a class of hybrid catalysts with p-toluenesulfonic acid (PTSA) as main catalyst, and hydrogensulfate ILs as support catalyst and extractant. Using the designed catalysts for methyl esterification of long-chain fatty acids, phase splitting can occur, resulting in ester-rich and catalyst-rich phases. Under optimal conditions, the conversion of palmitic acid (PA) gives methyl palmitate (MP) yield of 98.2 % in 3 hat 348.2 K. The catalysts are also applicable for effective conversion of other long-chain fatty acids and can be facilely recycled through liquid-liquid separation without loss of activity. COSMOtherm and Gaussian calculations were performed to rationalize the reactive separation behavior of the designed catalysts. The kinetic and thermodynamic properties of the esterification reaction were also examined using pseudo-homogeneous (PH) model with non-ideality corrections.

In the present work, the selective hydrodeoxygenation (HDO) performance of stearic acid over in situ MoS 2 catalysts produced from various Mo precursors was evaluated. Notably, the in situ MoS 2 catalyst generated from [N 8881 ] 2 MoO 4 —a Mo‐based ionic liquid (IL) with oil‐soluble property—achieves up to 99.9% of stearic acid conversion with the HDO product octadecane yield of 97.5% at 300°C, 8 MPa, and 6 h. The activity of [N 8881 ] 2 MoO 4 for catalyzing the selective HDO reaction is much better than commercial precursors like Mo(CO) 6 and (NH 4 ) 6 Mo 7 O 24 . The in situ MoS 2 catalysts were thoroughly characterized and analyzed to elucidate the experimental results. Moreover, the reaction pathway of stearic acid was proposed according to the product distribution, and the relative kinetic parameters were also calculated and discussed. The results indicate that applying Mo‐based IL as the precursor to generate in situ MoS 2 catalyst for the selective HDO of biolipids is highly interesting and desired.

Second-generation biodiesel is the dominant biomass-derived liquid fuel produced from nonedible natural or waste oils and fatty acids through selective oxygen removal. Here, we developed a highly selective sulfur-free NiMo/TiO2 catalyst by disentangling electronic and geometric effects to produce second-generation biodiesel via the hydrodeoxygenation of palmitic acid-one of the most common fatty acids in these feedstocks. An unprecedented hexadecane yield of 96.0% (on a mole basis) was achieved over the Ni1Mo1/TiO2 catalyst (with a Ni:Mo ratio of similar to 1:1) at 300 degrees C and 3 MPa H2. Kinetic studies reveal that the competition between hydrodeoxygenation (C-O scission) and decarbonylation (C-C scission) of the intermediate hexadecanol is key to optimizing selectivity. Furthermore, Mo incorporation markedly lowers the apparent activation energy of hydrodeoxygenation-especially in the Ni1Mo1/TiO2 catalyst, which has the lowest Ni-Ni coordination number. Combined with catalyst characterization, these findings elucidate a Mo-induced "Ni coordination environment"-directed reaction pathway: the superb hydrodeoxygenation activity and selectivity of Ni1Mo1/TiO2 stem from its abundant NiMo interfacial sites, where Mo-induced oxygen vacancies synergize with adjacent Ni sites to facilitate the adsorption of O-containing groups and subsequent C-O bond cleavage.

Due to escalating carbon emissions, increasing attention is being focused on the synthesis of biomass-derived liquid fuels with a low CO2 footprint. Currently, the dominant biobased liquid fuel in the diesel range is green diesel, which is produced via deoxygenation of non-edible natural/waste oils and their free fatty acid components into engine-compatible diesel-range alkanes. Industrially, sulfided NiMo or CoMo catalysts are typically used, leading to total hydrocarbon yields of 70–80 wt%. However, their inevitable sulfur leaching often contaminates the products and requires the addition of sulfur-containing agents. Here, we developed a highly selective sulfur-free Ni–Cu alloy catalyst by disentangling the electronic and size effects, to enable green diesel synthesis through the decarbonylation of palmitic acid—the most common fatty acid in these feedstocks. An unprecedented decarbonylation product (pentadecane) yield of 98% (on a molar basis) was achieved using a Ni–Cu alloy catalyst with a Ni/Cu ratio of 1:1 under mild reaction conditions (2 MPa H2, 250 °C). Minimal metal sintering or leaching was observed after multiple reuses. Kinetic studies showed that incorporating Cu into Ni markedly reduced both the apparent activation energy and the reaction order for the conversion of palmitic acid. These results, combined with catalyst characterization, reveal that introducing Cu into Ni not only facilitates the adsorption and activation of the carboxylic hydroxyl group to promote the reductive deoxygenation of palmitic acid into aldehyde/alcohol intermediates—the slow step in decarbonylation—but also weakens the adsorption of C–C bonds on Ni by enhancing its electron density.

A series of mesoporous polymers functionalized with different kinds and contents of Br & oslash; nsted acidic sites were designed and synthesized for NH 3 capture. The textural properties, morphologies and chemical structures of synthesized mesoporous polymers were characterized in details, and the NH 3 capture performance was evaluated systematically. It is found that the mesoporous polymers functionalized with phosphoric sites exhibit much better NH 3 capture performance at low pressures than those with carboxylic and sulfonic sites. Specifically, the NH 3 adsorption capacities of P(DVB-VPA)-4.0 can reach 4.82 mmol/g at 298.2 K and 0.033 bar. The excellent ability of P(DVB-VPA)-4.0 for selectively adsorbing low -content NH 3 from NH 3 /N 2 /H 2 and NH 3 /N 2 /CO 2 mixed gases was demonstrated by breakthrough experiments, and the adsorption of NH 3 by P(DVB-VPA)-4.0 is found to be mostly reversible. The thermodynamic properties and mechanism of NH 3 adsorption were also examined in depth, disclosing the important role of Br & oslash; nsted acidic sites in enhanced capture of low -content NH 3 by P(DVBVPA)-4.0.

There is a particular demand to explore low-volatility and structurally tunable absorbents for efficiency, selectivity and reversibility in capturing H2S. For the first time, the performance of deep eutectic solvents (DESs) composed of 1-ethyl-3-methylimidazolium chloride ([Emim]Cl) and acetamide (AA) were examined as physical absorbents for H2S capture. The physical properties of [Emim]Cl-AA DESs, and solubilities of both H2S and CO2 in them were measured. Relevant experimental results demonstrated that the solubilities of H2S in [Emim]Cl-AA DESs (1.1 mol/kg at 298.2 K and 1.023 bar) significantly exceed those of CO2 (0.040 mol/kg at 298.2 K and 1.027 bar). [Emim]Cl-AA DESs exhibit higher H2S solubilities and superior ideal H2S to CO2 selectivities (e.g., the ideal H2S/CO2 selectivity of [Emim]Cl-AA (1:0.5) is 28.5 at 298.2 K) than those physical absorbents ever reported. The recyclability of [Emim]Cl-AA DESs for H2S selective capture was also evaluated, which was found to be very stable in ten continuous absorption and regeneration cycle experiments. The mechanism of H2S capture by [Emim]Cl-AA DESs was finally illustrated at the molecular level with the support of theoretical calculations.

The capture the low-content NH3 from industrial streams, and recycle it as the feedstocks for industrial processes is very important. In this work, we reported the use of mesoporous polydivinylbenzene (PDVB) as the support of metal-based deep eutectic solvents (DESs) containing choline chloride (ChCl) and metal chlorides (SnCl2, FeCl3 or ZnCl2) for NH3 capture. The structure of composite materials was characterized in details, and the NH3 capture performance and mechanism of them were also examined in depth. Owing to the coordination interaction of metal ions with NH3, along with the hydrogen-bond interaction of - OH and Cl- with NH3, the DES@PDVB composites exhibit considerably high low-content NH3 capacities. The optimized sample ChCl + 2ZnCl2@PDVB1.5 can adsorb 7.43 mol/kg of NH3 at 25 degree celsius and 0.122 bar, which is advantageous over most other adsorbents fabricated in the literature. The mechanism of NH3 capture by DES@PDVB composites was also illustrated through spectroscopic characterizations.

The efficient deoxygenation of renewable biolipids into liquid alkanes within the diesel range is a key protocol for producing high-quality biofuels. In this work, the conversion of methyl palmitate and raw palm oil were accomplished utilizing a bifunctional catalyst of Ni catalysts supported on B2O3-ZrO2 under solvent-free conditions. Among various Ni loading ratios investigated, the catalyst featuring a 10 % Ni loading achieved 100 % conversion of methyl palmitate and 84.4 % of liquid yield, with approximately 65 % being C15 alkanes. Additionally, more than 91 % of hydrocarbons were also generated from raw palm oil. These results can be attributed to the synergistic interplay between the acid sites, following B2O3 modification, and the presence of Ni species. Furthermore, the analysis of product distribution, gas product detection and the kinetics calculation strongly supports that the deoxygenation process of methyl palmitate primarily follows the hydrodecarbonylation route, leading to the predominant formation of C15 alkane.

The design of novel practical catalysts is critical for the blossoming of biodiesel green-energy, in which Mo-based catalysts are of particular interest. In this work, an in-situ synthesis method was proposed to obtain a combo Mo-based ionic liquid and SAPO-11 catalyst. The catalyst presents both highly dispersed MoS2 as hydrodeoxygenation active sites and acidic sites for isomerization. MoS2 with a few fine layers can be identified based on TEM images and the Bronsted acid sites are dominant based on Pyridine-IR analysis. A great performance of MoS2/C(8)min-15 %SA can be obtained under optimized reaction conditions with 100 % conversion of methyl palmitate, 75.0 mol% hydrodeoxygenation to n-C-15-C-16, and 20.5 mol % isomerization to i-C-15-C-16. The structure and activity of the catalyst can be retained at least for 4 cycles. Thin layers and high sulfurization, large amount of Br & oslash;nsted acid sites, and suitable reaction conditions are key points to achieve a significant performance and avoid over cracking and deactivation. On basis of detected intermediates and kinetic data simulations, a complex reaction pathway was proposed and the specific k values for each elementary reaction were provided for the hydrodeoxygenation and isomerization of methyl palmitate.