Reaction Conditions Research Articles

Scalable synthesis of tranexamic acid under modest reaction conditions using early stage isomerization of dimethyl 1,4-cyclohexanedicarboxylate as a key step

A commercially scalable five-step synthetic process starting from cis/trans (7:3) mixture of dimethyl 1,4-cyclohexanedicarboxylate is devised for preparation of tranexamic acid with more than 99.5% purity. All impurities are controlled as per monograph. 47% overall yield over five steps has been achieved based on recovery. Epimerization of a cis-predominant isomeric mixture to trans predominant isomeric mixture under mild conditions followed by exploiting the difference in solubility to obtain trans isomer in very high purity is the key feature of the synthesis. In addition to this, use of readily available and cost efficient raw materials/reagents, recycling of cis isomer, explicit design of downstream processing enabling the retention of the trans-stereochemistry until final API are some of the highlights of this synthesis. This process also circumvents the use of hazardous chemicals and harsh reaction conditions making it greener and safer compared to the previous reports.”

Synthesis of uniform spherical silver powder without dispersants in a confined impinging-jet reactor

Sliver powder is the most common and extensively utilized precious metal powder in electronics, primarily for electronic paste. Herein, micron-sized spherical silver powder was synthesized via a liquid phase reduction method employing silver nitrate as the source of silver and ascorbic acid as the reducing agent in a confined impinging jet reactor (CIJR). The impact of the molar ratio between silver nitrate and ascorbic acid, the flow rate, and the temperature on the particle size of silver powder was investigated. The optimal process conditions for silver powder are as follows: maintain a molar ratio of 1:1 and control the feeding rate at 10ml/min while operating at 50 ° C. The confined impinging jet reactor offers enhanced control over reaction conditions during the synthesis of silver powder, surpassing the capabilities of traditional batch reactors. The aforementioned optimized methodology was employed to successfully synthesize uniform and spherical silver powder (with an aspect ratio approaching 1) in the low Reynolds number jet, resulting in an average particle size of d50 = 0.83 μm and a standard deviation of 0.07, without the addition of dispersant. The synthesis method presented here improves the performance of silver powder, simplifies the production process, reduces energy consumption, and minimizes waste generation. These advances yield significant environmental and economic benefits. In the future, with the continuous development and optimization of microreactor technology, this synthesis method is anticipated to play a more prominent role in the commercial-scale production and application of micrometer-sized silver powder.

Construction of Br-Cu2O@NiFe-LDHs Z-scheme heterojunction and photocatalytic degradation of catechol

Facet regulation and construction of heterojunctions are important means to enhance the photocatalytic performance of single-phase materials. In this paper, the facet index of Cu2O was changed through Br doping, and then a Br doped Cu2O@NiFe-LDHs Z-scheme heterojunction (BC@LDHs) was constructed for photocatalytic degradation of catechol. The optimal conditions for photocatalytic degradation reaction were explored; the kinetic and thermodynamic parameters of the reaction, as well as the stability and reusability of the material were studied. Under optimal reaction conditions, the photocatalytic degradation of catechol can reach up to 95.68% by BC@LDHs, which is much higher than that of single-phase materials and Cu2O@LDHs. By combining experiments and theoretical calculations, the intrinsic reasons and mechanisms for Br doping to enhance the photocatalytic degradation performance of BC@LDHs Z-scheme heterojunctions were fully explored from the perspectives of band structure and oxygen adsorption, determination of built-in electric field in Z-scheme heterojunctions, calculation of built-in electric field strength and bulk charge separation efficiency. This work proposes the insights that using Br doping to alter exposed facets and regulate the strength of the built-in electric field in Br-Cu2O@NiFe-LDHs heterojunctions, thereby promoting its efficient photocatalytic degradation.

Deoxygenation of benzylphenyl sulfones using 1,2-bis(diphenylphosphino)ethane (dppe)/NBS under metal-free conditions

An efficient route for the chemoselective deoxygenation of benzylphenyl sulfones to the corresponding sulfides has been developed using a mixture of 1,2-bis(diphenylphosphino)ethane(dppe) and NBS as an effective promoter. This is the first development on the deoxygenation of diverse benzylphenyl sulfones under metal-free conditions. The mild reaction conditions, formation of the water soluble by-product and tolerance of a wide range of functional groups promote its broad applications in organic synthesis.

Xanthenes: Novelty and Green Photocatalysis for the Formation of Carbon-carbon or Carbon-heteroatom Bond

: This review covers photoreduction reactions using xanthenes reported from 2011 to date and compares them with the conventional photocatalytic method. Xanthenes have strong absorption in the visible light spectrum (520-550 nm), and their redox potential resembles organometallic complexes, such as those containing Ir or Ru, and they are also easy to handle and accessible. In addition to being metal-free, photocatalysis with xanthenes is performed under mild reaction conditions. For instance, no radical initiators are needed because the energy sources are led devices or household lamps, most reactions are performed at room temperature in common solvents (MeOH, MeCN, acetone, DMSO), and an anhydrous or inert atmosphere is usually not required. As a result, xanthene dyes hold the promise of a more environmentally friendly synthesis of organic compounds.

Highly Stable Carboranyl Ligated Gold Nano-Catalysts for Regioselective Aromatic Bromination.

Achieving electronic/steric control and realizing selectivity regulation in nanocatalysis remains a formidable challenge, as the dynamic nature of metal-ligand interfaces, including dissolution (metal leaching) and structural reconstruction, poses significant obstacles. Herein, we disclose carboranyls (CBs) as unprecedented carbon-bonded functional ligands (Eads.CB-Au(111)=-2.90 eV) for gold nanoparticles (AuNPs), showcasing their exceptional stabilization capability that is attributed by strong Au-C bonds combined with B-H⋅⋅⋅Au interactions. The synthesized CB@AuNPs exhibit core(Aun)-satellite(CB2Au-) structure, showing high stability towards multiple stimuli (110 °C, pH=1-12, thiol etchants). In addition, different from conventional AuNP catalysts such as triphenylphosphine (PPh3) stabilized AuNPs, dissolution of catalytically active gold species was suppressed in CB@AuNPs under the reaction conditions. Leveraging these distinct features, CB@AuNPs realized outstanding p : o selectivities in aromatic bromination. Unbiased arenes including chlorobenzene (up to >30 : 1), bromobenzene (15 : 1) and phenyl acrylate were examined using CB@AuNPs as catalysts to afford highly-selective p-products. Both carboranyl ligands and carboranyl derived counterions are crucial for such regioselective transformation. This work has provided valuable insights for AuNPs in realizing diverse regioselective transformations.

MOSP: A user-interface package for simulating metal nanoparticle's structure and reactivity under operando conditions.

The structures of metal nanoparticles (NPs) significantly influence their catalytic reactivities. Recent in situ experimental observations of dramatic structural changes in NPs underscore the need to establish a dynamic structure-property relationship that accounts for the reconstruction of NPs in reactive environments. Here, we present the MOSP, a free and open-source graphical user interface (GUI) package designed to simulate the structure and reactivity of metal NPs under operando conditions. MOSP integrates two models: the multiscale structure reconstruction model predicting equilibrium metal NP structures under specific reaction conditions and the kinetic Monte Carlo model simulating the reaction dynamics. This combination allows for the exploration of the dynamic structure-property relationships of NPs. MOSP enhances user accessibility through its intuitive GUI, facilitating easy input, post-processing, and visualization of simulation data. This article is the release note of MOSP, focusing on its implementation and functionality.

Kinetic Insights into Methanol Synthesis from CO2 Hydrogenation at Atmospheric Pressure over Intermetallic Pd2Ga Catalyst

AbstractThis study presents a single‐site microkinetic model for methanol synthesis by CO2 hydrogenation over intermetallic Pd2Ga/SiO2. A reaction path analysis (RPA) combining theoretical results and realistic catalyst surface reaction data is established to elucidate the reaction mechanism and kinetic models of CO2 hydrogenation to methanol and CO. The RPA leads to the derivation of rate expressions for both reactions without presumptions about the most abundant reactive intermediate (MARI) and rate‐determining step (rds). The formation of H2COOH* is found to be the rds (step 19) for methanol synthesis via the formate pathway, with CO2 and H‐atoms adsorbed on intermetallic sites as the MARIs. The derived kinetic model is corroborated with experimental data acquired under different reaction conditions, using a lab‐scale fixed‐bed reactor and Pd2Ga/SiO2 nanoparticles prepared by incipient wetness impregnation. The excellent agreement between the experimental data and the kinetic model (R2 = 0.99) substantiates the proposed mechanism with an activation energy of 61.52 kJ mol‐1 for methanol synthesis. The reported catalyst exhibits high selectivity to methanol (96%) at 1 bar, 150 °C, and H2/CO2 ratio of 3:1. These findings provide critical insights to optimize catalysts and processes targeting CO2 hydrogenation at atmospheric pressure and low temperatures for on‐demand energy production.

1,2,3-Triazole-Guided Multi-Component Sonogashira Coupling of Substituted Benzosuberenes Derived from Cedrus deodara Oil

AbstractHerein, Sonogashira coupling at the vinyl bromide position of triazole-bearing benzosuberene has been introduced for the synthesis of potentially bioactive 1,2,3-triazole and conjugated enynes containing benzosuberene analogues. The instalment of triazole moiety on the allylic position dictates the Sonogashira coupling at the vinylic position, the absence of which failed to execute the desired reaction. The Cu-catalyzed cycloaddition initially led to the incorporation of 1,2,3-triazole, which subsequently directed the Pd/Cu-catalyzed Sonogashira coupling to deliver new class of benzosuberene analogues in appreciable yields. The regioselective synthesis of 1,2,3-triazole and conjugated enynes containing benzosuberene analogues has been reported under operationally simple and milder reaction conditions.

Metathesis Mastery: Crafting Linear Triquinane Frameworks for Natural Product Synthesis

AbstractOrganic and medicinal chemists have shown great interest in developing simple approaches for creating linear triquinane structures, as they are crucial for synthesizing both natural and synthetic products. Linear triquinane shows various biological characteristics like being commonly used for antitumor, antibacterial, and antimalarial purposes, making it a popular subject of study among synthetic chemists. These come from different sources like marine organisms, plants, and fungi and make up a significant group of sesquiterpenoids. These can be classified as cis‐syn‐cis or cis‐anti‐cis based on the stereochemistry at the ring junction, with cis‐anti‐cis being the most common type and exhibiting significant biological activity. In this review, we summarized different methods using a combination of photothermal and olefin metathesis strategy to construct a triquinane framework by utilizing both traditional heat and microwave radiation. Some commonly used synthetic methods, including metathesis protocol and key reactions like Grignard reaction and Diels–Alder reaction, were utilized together with ring‐closing, ring‐opining, and ring‐rearrangement metathesis to create the linear triquinane core for use in total synthesis of natural products. Additionally, the use of photothermal olefin metathesis along with Hosomi‐Sakurai reaction conditions allows for the creation of intricate polyquinanes, which can be used to produce complex natural compounds and for designing unique molecules theoretically.

In Situ Surfaced Mn-Mn Dimeric Sites Dictate CO Hydrogenation Activity and C2 Selectivity over MnRh Binary Catalysts.

Massive ethanol production has long been a dream of human society. Despite extensive research in past decades, only a few systems have the potential of industrialization: specifically, Mn-promoted Rh (MnRh) binary heterogeneous catalysts were shown to achieve up to 60% C2 oxygenates selectivity in converting syngas (CO/H2) to ethanol. However, the active site of the binary system has remained poorly characterized. Here, large-scale machine-learning global optimization is utilized to identify the most stable Mn phases on Rh metal surfaces under reaction conditions by exploring millions of likely structures. We demonstrate that Mn prefers the subsurface sites of Rh metal surfaces and is able to emerge onto the surface forming MnRh surface alloy once the oxidative O/OH adsorbates are present. Our machine-learning-based transition state exploration further helps to resolve automatedly the whole reaction network, including 74 elementary reactions on various MnRh surface sites, and reveals that the Mn-Mn dimeric site at the monatomic step edge is the true active site for C2 oxygenate formation. The turnover frequency of the C2 product on the Mn-Mn dimeric site at MnRh steps is at least 107 higher than that on pure Rh steps from our microkinetic simulations, with the selectivity to the C2 product being 52% at 523 K. Our results demonstrate the key catalytic role of Mn-Mn dimeric sites in allowing C-O bond cleavage and facilitating the hydrogenation of O-terminating C2 intermediates, and rule out Rh metal by itself as the active site for CO hydrogenation to C2 oxygenates.

Isopropanol/Water Bi‐Solvent Enhanced the Catalytic Transfer Hydrogenation of Levulinic Acid to γ‐Valerolactone over Ru‐PC Catalyst

AbstractCatalytic transfer hydrogenation of levulinic acid (LA) to γ‐valerolactone (GVL) was attractive in biomass conversions since GVL is highly useful in different applications, such as polymer synthesis, fuel, and food. Various catalytic systems were reported for the reaction, yet harsh reaction conditions were generally required, which could restrict the scaling up of the reaction. Herein, we developed an effective and green bi‐solvent system of isopropanol/water for the catalytic transfer hydrogenation of LA to GVL over a ruthenium–phosphorous carbon (Ru‐PC) catalyst. It was found that the presence of water in the solvent system promoted the production of GVL from LA. The effect of isopropanol/water ratios and other reaction conditions were investigated, exhibiting that 93.8% yield of GVL was achieved using isopropanol/water ratio of 2.5:2.5 at 140 °C for 4 h and over Ru‐PC catalyst. Combining water and organic solvent not only reduced the usage of organic solvent but also created an effective bi‐solvent system for catalytic reactions.

Visible Light-Assisted Periodate Activation Using Carbon Nitride for the Efficient Elimination of Acid Orange 7

The development of appropriate and effective periodate (PI) activation technology is currently a popular research area. This study presents a novel efficient photocatalytic activation approach of PI for pollutant degradation based on carbon nitride (g-C3N4) and visible light (Vis). The results show that the system can remove 92.3% of acid orange 7 (AO7) within 60 min under the g-C3N4/PI/Vis reaction system. The degradation rate constant (kobs) reached 4.08 × 10−2 min−1, which is 4.21, 5.16 times, and 51.3 times higher than that of the g-C3N4/Vis system (9.7 × 10−3 min−1), PI/Vis system (7.9 × 10−3 min−1) and the g-C3N4/PI system (7.96 × 10−4 min−1), respectively. Clearly, the addition of PI significantly enhances the degradation efficiency of AO7 in the system. Additionally, under the same reaction conditions, the presence of PI showed excellent oxidation capacity in the photoactivation process compared with other common oxidants, such as peroxymonosulfate, peroxydisulfate, and H2O2. Moreover, the g-C3N4/PI/Vis system showed excellent removal of AO7 across a wide range of pH levels and in the presence of various anions. Electron paramagnetic resonance (EPR) and quenching experiments suggested that the superoxide anions (•O2−) and singlet oxygen (1O2) dominated in the oxidation of pollutants in the g-C3N4/PI/Vis system. In addition, the catalyst showed relative stability during cyclic testing, although a slight reduction in degradation efficiency was observed. In brief, the g-C3N4/PI/Vis system is highly efficient and environmentally friendly, with significant application potential in wastewater treatment.

Studies of Phase Transformation Kinetics in the System of Nanocrystalline Iron/Ammonia/Hydrogen at the Temperature of 350 °C by Means of Magnetic Permeability In Situ Measurement

The kinetics of phase transformations in the nitriding process α-Fe → γ’-Fe4N → ε-Fe3-2N of the pre-reduced iron ammonia synthesis catalyst was investigated under in situ conditions (atmospheric pressure, 350 °C) by measuring changes of mass, gas phase composition, and magnetic permeability in a differential tubular reactor. The iron nanocrystallite size distribution according to their specific active surface areas was measured, and it was found that the catalyst is bimodal as the sum of two Gaussian distributions, also differing in the value of the relative magnetic permeability. Relative magnetic permeability of small α-Fe crystals in relation to large crystals is higher by 0.02. In the area of α → γ’ transformation, the magnetic permeability dependencies change, proving the existence of two mechanisms of the α-Fe structure change in the α-Fe → γ’-Fe4N transformation. In the first area, a solution of α-Fe (N) is formed with a continuous and insignificant change of the crystal lattice parameters of the iron lattice. In the second area, there is a step, oscillatory change in the parameters of the iron crystal lattice in FexN (x = 0.15, 0.20, 0.25 mol/mol). In the range of γ’-Fe4N → ε-Fe3-2N transformation, a solution is formed, with nitrogen concentration varying from 0.25–0.45 mol/mol. During the final stage of the nitriding process, at a constant value of the relative magnetic permeability, only the concentration of nitrogen in the solution εr increases. The rate of the phenomenon studied is limited by a diffusion rate through the top layer of atoms on the surface of iron nanocrystallite. The estimated value of the nitrogen diffusion coefficient varied exponentially with the degree of nitriding. In the area of the solution, the diffusion coefficient is approximately constant and amounts to 5 nm2/s. In the area of oscillatory changes, the average diffusion coefficient changes in the range of 3–11 nm2/s, and is inversely proportional to the nitrogen content degree. The advantage of the research method proposed in this paper is the possibility of simultaneously recording, under reaction conditions, changes in the values of several process parameters necessary to describe the process. The research results obtained in this way can be used to develop such fields of knowledge as heterogeneous catalysis, materials engineering, sensorics, etc.

Access to Seleno‐Functionalized Thiazolo[3,2‐a]Pyrimidinones and Pyrimido[2,1‐b][1,3]Thiazinones via Selenocyclization of 2‐Alkenylthiopyrimidinones and Their Fused Analogs

AbstractThe methodology of electrophilic selenylation/cyclization of 2‐alkenylthiopyrimidinones and their fused analogs underlies most of the reported synthetic approaches to seleno‐functionalized thiazolo[3,2‐a]pyrimidinones and pyrimido[2,1‐b][1,3]thiazinones. We have developed a novel implementation of this strategy using as reagent phenylselenyl chloride or the visible‐light‐induced radical‐generating (PhSe)2/CBr4 system. The effect of the unsaturated substrate structure and reaction conditions on the selenocyclization regioselectivity has been revealed and analyzed in detail. It has been established that regardless of the conditions used, 2‐allylthiopyrimidinones react with selenylating agents via electrophilic 5‐exo‐trig cyclization mainly involving the N1 nitrogen atom to give selenium‐containing thiazolo[3,2‐a]pyrimidinones as major products. On the contrary, the selenocyclization with 2‐cinnamylthiopyrimidinones is dominated by the 6‐endo‐trig mode: it mostly involves six‐membered ring closure at the N1 or N3 atom thus leading to selenylated pyrimido[2,1‐b][1,3]thiazinones, with the regiochemistry governed by the position and nature of the substituents on the substrate pyrimidine ring. However, some of the fused cinnamylthio‐substituted substrates yield 5‐exo‐trig cyclized products in the LiClO4/МеNO2 system (a sufficiently polar solvent with a strong electrolyte added).

Sequential Aerial Oxidation And Atom‐economical C‐3 Chalcogenation Of Indolines Facilitated By Potassium Tert‐butoxide

An operationally straightforward and highly efficient potassium tert‐butoxide facilitated protocol for the C‐3 chalcogenation of indolines under catalyst and additive‐free conditions has been established under ambient temperature. The salient features of the process include the development of transition metal‐free, oxidant‐free and iodine‐free, atom‐economic and cost‐effective reaction conditions at room temperature in DMSO as solvent for regioselective generation of 3‐chalcogenyl indoles in high yields. The mechanistic interpretation through controlled experiments and analysis of intermediates suggests the prevalence of the ionic pathway. The reaction is scalable to gram‐scale without a significant decrease in product yield, indicating its potential for large‐scale applications. This protocol offers a practical and environment friendly approach to accessing a diverse range of 3‐arylthioindoles and 3‐arylselenylindoles withstanding electron releasing and withdrawing substituents in good to excellent yields. Interestingly, the biological evaluation of the 3‐arylselenylindole products exhibited significant activity against breast cancer and triple‐negative breast cancer cell lines MCF‐7, and MDA‐MB 231. These results indicate the derivatives to be potent candidates for further SAR study.

Carbon-based magnetic nano-particle utilizing nano-biochar as core and its immobilizing lipase for biodiesel preparation

Using the transesterification capacity of lipase to produce eco-friendly biodiesel is a promising method for the achievement of a Net Zero future. The method of immobilized lipase enhances the usability of the enzyme and improves its stability. Carbon-based magnetic nano-particles (C-MNPs) with nano-biochar as the precipitation core were prepared as the support to immobilize Candida antarctica lipase B (CalB) for biodiesel preparation. The nano-biochar particles were derived through the calcination of rice straw powder and subsequently ground to the nanoscale. FT-IR, XRD, SEM, and VSM results showed that the obtained C-MNPs with a diameter of 13–17 nm were showing excellent superparamagnetism, and effectively immobilized the lipase on them (CalB@C-MNPs). The optimal reaction conditions in a 100-mL stoppered flask for biodiesel production were dissolving 5 g soybean oil in 3 mL tert-butanol solvent, adding 1.16 mL methanol (molar ratio of methanol to oil 5:1), 0.15 mL water, and 0.2 g CalB@C-MNPs, and then shaking at 200 rpm and 30 °C for 24 h. Its primarily optimized conversion efficiency of biodiesel was 83.1 %. After repeated use of immobilized CalB for 8 cycles, the remaining activity and biodiesel yield were 79.7 % and 66.3 %, respectively. As a robust catalyst, CalB@C-MNPs exhibited outstanding transesterification efficiency, the ability for rapid recovery under an external magnetic field, and a promising candidate in biodiesel production.

Hydrogenation‐Rearrangement of Furfural over Cu‐based Catalysts with Abundant Lewis Acid Sites

AbstractCyclopentanone (CPO) and cyclopentanol (CPL), derived from renewable biomass resource hemicellulose, are considered sustainable chemicals that can substitute fossil‐based products, which could be obtained through the hydrogenation‐rearrangement reaction of furfural (FFA). However, the inevitable condensation reactions of FFA and furfuryl alcohol (FA) in aqueous solutions generate humins and result in carbon loss, limiting the industrial application of this process. Herein, a series of Cu‐based catalysts were synthesized using the reverse co‐precipitation method with various metal promoters and applied in the FFA hydrogenation‐rearrangement reaction. The highest yield of 97.1 % CPO/CPL achieved in a typical reaction condition at 200 °C, 4 MPa, in 20 wt % isopropanol‐water mixed solvent over CuZnZr catalyst and the recyclability test confirmed that the catalyst had excellent stability. Experimental studies and characterizations showed that the enhanced performance could be attributed to the adequate Lewis acid sites, regulated through the synergistic interaction between Cu, Zn, and Zr compounds. The simultaneous introduction of Zn and Zr promotes the Cu reduction, and results in more dispersed Cu0 and Cu+, providing an ample and reliable active site. This study outlines a viable method for the catalyst designing and valorizing biomass into high‐value‐added products.

Cu(II)-tyrosinase enzyme catalyst mediated synthesis of mosquito larvicidal active pyrazolidine-3,5-dione derivatives with molecular docking studies and their ichthyotoxicity analysis

The objective of this study was to develop pyrazolidine-3,5-dione derivatives with potential as environmentally friendly pesticides for pest control, specifically focusing on their efficacy as larvicidal agents. A novel one-pot synthesis of multicomponent pyrazolidine-3,5-dione derivatives (1a-m) was accomplished via the grindstone method using Cu(II)tyrosinase enzyme as a catalyst under mild reaction conditions, yielding 84%–96%. The synthesised derivatives (1a-m) were characterized using various spectroscopic methods (mass spectrometry, elemental analysis, FT-IR, and 1H and 13C NMR). NMR characterisation using DMSO-d6 as a solvent. The larvicidal and antifeedant activities of the synthesised compounds were screened and in silico computational studies were performed. The larvicidal activity against Culex quinquefasciatus and antifeedant activity against Oreochromis mossambicus were evaluated. Among the synthesised compounds, compound 1c demonstrated superior efficacy (LD50: 9.7 μg/mL) against C. quinquefasciatus compared to permethrin (LD50: 17.1 μg/mL). Regarding antifeedant activity, compounds 1a, 1e, 1f, 1j, and 1k exhibited 100% mortality at 100 μg/mL. Molecular docking analysis was performed to assess the binding capacity of a mosquito odorant-binding protein (3OGN) from Culex quinquefasciatus to compound 1c. The results revealed that compound 1c had a docking score of -10.4 kcal/mol, surpassing that of standard permethrin (-9.5 kcal/mol). Furthermore, DFT calculations were conducted to acquire theoretical data aligned with the experimental FT-IR results. According to experimental research, compound 1c demonstrates promising larvicidal activity against mosquito larvae of C. quinquefasciatus.

Effect of Ni/tire rubber carbon as catalyst in the hydrodeoxygenation of used vegetable oil: biofuel evaluation in the reduction of atmospheric emissions

Abstract The sustainable valorization of discarded resources remains a challenge, and their requirements are crucial for long-term development. In this sense, we characterize biofuels of the diesel range obtained with used vegetable oils subjected to hydrodeoxygenation with Ni supported on tire rubber carbon obtained by the pyrolysis of waste tires. Under optimal reaction conditions, the vegetable oil conversion was 81.2 % with a selectivity of 82.3 % to C10–C18 alkanes, which is supported by the results of the catalyst characterization. A vertical direct injection engine was used to compare the behavior of the renewable biofuel and petroleum diesel blends. In comparison to petroleum diesel, the blends with renewable biofuel showed minimal power loss. In addition, the use of blends containing biofuels allowed a reduction of 25 % of CO and HC, as well as a decrease of 48 % is smoke compared to petroleum diesel, due to the fact that renewable biofuels improved evaporation after injection, reduced the density, and did not contain aromatic components.