Efficient Solid Catalyst Research Articles

Crosslinked Cation Exchange Resin with -SO3H Groups as an Efficient Solid Catalyst for the Ketalization of Ethyl Acetoacetate with Glycols

Crosslinked Cation Exchange Resin with -SO3H Groups as an Efficient Solid Catalyst for the Ketalization of Ethyl Acetoacetate with Glycols

Calcium single atoms stabilized by nitrogen coordination in metal–organic frameworks as efficient solid base catalysts

Considerable attention has been paid to the preparation of single-atom solid base catalysts (SASBCs) owing to their high activity and maximized utilization of basic sites. At present, the reported fabrication methods of SASBCs, such as two-step reduction strategy and sublimation capture strategy, require high temperature. Such a high activation temperature is easy to cause the sublimation loss of alkali or alkaline earth metal atoms and destructive to the support structure. Herein, a new SASBC, Ca1/UiO-67-BPY, is fabricated, in which the alkaline earth metal Ca sites are immobilized onto N-rich metal–organic framework UiO-67-BPY at room temperature. The results show that the atomic configuration of Ca single atoms is coordinated by two N atoms in the framework. The obtained Ca SASBC possesses ordered structure and exhibits high product yield of 87.2% in the Knoevenagel reaction between benzaldehyde and malononitrile. Furthermore, thanks to the Ca single atoms sites anchored on UiO-67-BPY, the Ca1/UiO-67-BPY catalyst also shows good stability during cycles. This work might offer new insight in designing SASBCs for different base-catalyzed reactions.

Renewable biomass based jet fuel: Aldol condensation of furfural with 3-pentanone over calcium zirconium mixed oxide catalyst

Furfural is a biomass-derived chemical that can be converted into different valuable chemicals using green processes. The current study deals with a highly efficient, robust, and selective solid catalyst for the aldol condensation of furfural and 3-pentanone to synthesize 1-furan-2-yl-2-methylpent-1-en-3-one under environmentally benign conditions. CaZr (different molar ratios of Ca and Zr) mixed oxide (MO) catalysts along with reference CaO and ZrO2 catalysts were prepared by the hydrothermal technique and investigated for the current reaction. Among all, CaZr (1:2) MO catalyst was found to be the best for the conversion of furfural due to its desirable basic strength with good surface area and reusability characteristics. Furfural conversion and 1-furan-2-yl-2-methylpent-1-en-3-one selectivity were found to be 94 % and 98 %, respectively, under optimized reaction conditions. Effect of various reaction parameters was studied carefully to achieve the maximum yield of the required product. Reaction mechanism and kinetics were developed. The reaction aligns with the LHHW mechanism, and the activation energy was determined to be 10.40 kcal/mol.

Experimental and Theoretical Investigation of Interfacial Engineering in Fe2O3/NiFe2O4 Heterostructures toward the Cycloaddition of CO2 with Styrene Oxide.

The chemical fixation of CO2 into epoxides for the synthesis of cyclic carbonates is an appealing solution to both reduce global CO2 emission and produce fine chemicals, but it is still a prime challenge to develop a low-cost, earth-abundant, yet efficient solid catalyst. Herein, Fe2O3/NiFe2O4 heterostructures are facilely constructed for the highly efficient cycloaddition of CO2 with styrene oxide (SO) to produce styrene carbonate (SC). Both experimental findings and density functional theory (DFT) calculations substantiate the prominent electron transfer and charge redistribution within the heterointerfaces between the biphasic components, which induce a unique interfacial microenvironment that can facilitate the adsorption and activation of SO. This endows the biphasic catalyst with a substantially higher reactivity than the individual components. This study sheds new insights into the establishment of heterostructured catalysts consisting of transitional metal oxides for the high-efficiency production of SC from the cycloaddition of CO2 with SO.

Sn-modified SBA-15 with tailored acid properties for efficient 5-hydroxymethylfurfural production from glucose

Interest in production and utilization of 5-hydroxymethylfurfural (5-HMF) has risen greatly as 5-HMF is considered as an extremely important platform compound. It remains a huge challenge to develop efficient and low-cost solid catalysts with suitable acid properties for sustainable production of 5-HMF from glucose. Herein, a bifunctional Sn-modified SBA-15 (Sn–OH/SBA-15) catalyst containing both Lewis and Brønsted acid sites was fabricated. Dimethyldichlorostannane was grafted onto mesoporous SBA-15, and the methyl groups were then converted to hydroxyl groups by calcination. The synergistic effects of Lewis and Brønsted acid significantly boosted the synthesis of 5-HMF from glucose adopting the one-pot method. By optimizing the reaction conditions, the Sn–OH/SBA-15 sample was able to achieve a glucose conversion of 96.9% with a 5-HMF yield of 70.6% (180 °C, 5 h). Moreover, the catalyst demonstrated superior recyclability and reusability. This work would enlighten the exploitation and preparation of highly efficient catalysts for the transformation of carbohydrates into value-added chemicals.

SrCaAl mixed metal oxides derived from LDH precursor as a novel and efficient solid base catalyst for Knoevenagel condensation reaction: Multivariate optimization study

The Knoevenagel condensation reaction is one of the most important reactions in the industry for the synthesis of organic materials, medicinal, and biological compounds. In this work, we have proposed an original and efficient solid-base catalytic system for the Knoevenagel condensation reaction. For the first time, a mixed oxide catalyst derived from hydrotalcite-like Sr0.5Ca2.5Al precursor was synthesized by co-precipitation method and subsequently calcined for 5 h at 850 °C. The catalysts were characterized by various techniques. The Sr0.5Ca2.5Al mixed oxide was also compared with the usual Ca3Al sample in terms of structural characteristics and catalytic activity in the Knoevenagel reaction between active methylene compounds and benzaldehyde. The findings revealed that the Sr0.5Ca2.5Al mixed oxide sample is considerably active in this reaction compared to the Ca3Al sample due to its stronger basicity. The kinetics of the Knoevenagel condensation reaction over the Sr0.5Ca2.5Al catalyst was investigated and indicated that it follows from the second-order model. The stability and reusability of the catalyst sample were studied and it was found that the Sr0.5Ca2.5Al catalyst has high stability and a good lifetime. The effects of reaction time, amount of catalyst, and reaction temperature on benzaldehyde conversion (%) and product selectivity (%) were assessed in this study using the Box-Behnken design. The appropriateness of the quadratic regression model was evaluated through the ANOVA method. Under optimal conditions, the conversion percentage of benzaldehyde and product selectivity reached 97% and 84%, respectively.

Copper-induced formation of Lewis acid sites enhancing sulfated zirconia catalyzed i-butane normalization

Sulfated zirconia (SO42-/ZrO2) has been reported as an efficient and stable solid superacid catalyst for normalizing i-butane to n-butane, and may potentially substitute Pt-based catalysts. In this work, sulfated zirconia with Cu addition (Cu-SO42-/ZrO2) is prepared through a one-step method and exhibits comparable performance to commercial Pt-Cl/Al2O3, with an i-butane average conversion of 43.8% and n-butane average selectivity as high as 86.1%, while maintaining a stable n-butane yield for up to 120 hours. The relationship between Cu-promoter-induced physicochemical properties and catalytic performance for sulfated zirconia catalysts is investigated in detail, with the help of XPS, NH3-TPD, pyridine-IR, and density functional theory calculation. A volcano-type relationship is found between Cu content and n-butane yield, where n-butane yield first increases from 32.23% to 37.71%, and then decreases to 29.56%, with the gradual increase of Cu content. The moderate Cu species additive is beneficial to release Zr Lewis acid site from sulfate and increase its Lewis acid density, which accounts for its excellent catalytic selectivity for i-butane normalization. The excess Cu promoter covers the exposed Zr Lewis active sites, leading to the decayed i-butane conversion. Therefore, Lewis active sites density is regarded as descriptor to corelate n-butane yield, accounting for the volcano relationship between Cu content and n-butane yield for Cu-SO42-/ZrO2. This work demonstrates the feasibility of Cu modification and provides insight into the promotion mechanism, which may be extended to other solid superacid catalysts beyond sulfated zirconia.

Utilization of Keplerate-type polyoxomolybdates {Mo132} supported on hierarchical porous SOM-ZIF-8 as reusable catalyst boosts biodiesel production from acidic soybean oils by simultaneous transesterification-esterifications

Improving the reactant mass transfer on the catalyst surface is a feasible approach to fabricate a robust solid catalyst for efficiently promoting the biomass macromolecules-involving reactions, specifically for biodiesel production by using non-edible acidic oils as feedstocks. In this premise, to reduce the mass transfer resistance, the hierarchical porous SOM-ZIF-8 was firstly synthesized using polystyrene spheres (PS) as templates and then employed as catalyst supports for loading of Keplerate-type polyoxomolybdates {Mo132} to prepare a novel {Mo132}@SOM-ZIF-8 solid acid catalyst. The catalyst characterization results revealed that the active species of {Mo132} clusters were well-dispersed on the SOM-ZIF-8 support and the primary framework of the SOM-ZIF-8 support remained nearly unaltered after the preparation processes. This prepared catalyst featured three-dimensional ordered hierarchical porous structure and dual Bronsted-Lewis acid sites, with a large surface area of 736.26 m2/g and high acidity of 903 μmol/g, presenting high activities for concurrent triglyceride transesterification and free fatty acids (FFAs) esterification. With the acidic soybean oils as feedstocks, 93.9 % of oil conversion and full FFA conversion to biodiesel were achieved over this solid catalyst at 130 °C for 8 h with a catalyst loading of 2 wt%, thus imparting the great potential for a one-pot efficient biodiesel manufacture from the acidic oils to comply with the demand of green and clean production. The synergy between the hierarchical porous structure and the strong acidity emerged, thus boosting the catalytic performance of this solid catalyst for the heterogeneous biodiesel production. The good FFA and moisture-resistance capacity was shown for this catalyst even in the case of moisture content of 3 % and FFA content of 25 %. Further, this catalyst showed excellent reusability without significantly losing its catalytic performance even after five runs, providing a deeper insight into constructing efficient solid catalysts with hierarchical porous structure that are utilized for cost-effective production of biodiesel from the non-edible acidic oils.

β supported Fe2(MoO4)3: An efficient solid acidic heterogeneous catalyst for the synthesis of 2-Ethoxyethyl acetate

A series of xFe2(MoO4)3/β catalysts with different loading of Fe2(MoO4)3 on the β zeolite were successfully prepared and used as catalysts for the synthesis of 2-ethoxyethyl acetate (EGEA) from ethyl acetate (EA) and 2-ethoxyethanol (EGEE). Fe2(MoO4)3 is successfully loaded on β zeolites according to the results of H2-TPR, UV–vis spectra, FT-IR spectra and XRD. According to the results of NH3-TPD and IR spectra of the pyridine adsorbed, the xFe2(MoO4)3/β has high proportion of medium to total acid density and bifunctional acids containing both Brønsted and Lewis acidic sites after the loading of Fe2(MoO4)3. The proportion of medium to total acid density increased from 30.9% to 44.58% with the Fe2(MoO4)3 loading increased from 0 to 13.3 wt%. The conversion of EGEE and selectivity to EGEA over 8.1%Fe2(MoO4)3/β are 74.8% and 100% respectively under the optimal reaction conditions, and the activity of 8.1%Fe2(MoO4)3/β almost maintained unchanged after 4 cycles. The high activity of 8.1%Fe2(MoO4)3/β is attributed to large specific surface area, the high proportion of medium-total acid density (44.58%), high Lewis/Brønsted ratio (3.86) and the synergistic action of the Brønsted and Lewis acidic sites.

Insights into non-crystalline structure of solid solution Ce-Mn co-oxide nanofibers for efficient low-temperature toluene oxidation.

The controllable preparation of efficient non-crystalline solid solution catalysts is a great challenge in the catalytic oxidation of volatile organic compounds. In this work, series non-crystalline solid solution structured Ce-Mn co-oxide nanofibers were creatively prepared by adjusting Ce/Mn molar ratios using electrospinning. 0.20CeMnOx (the ratio of Ce to Mn was 0.2) displayed an outstanding low-temperature toluene oxidation activity (T90 = 233 °C). The formation of the amorphous solid solution and the unique nanofiber structure both contributed to a large specific surface area (S = 173 m2 g-1) and high adsorbed oxygen content (Oads/O = 41.3%), which enhanced the number of active oxygen vacancies. The synergies between non-crystalline structure and active oxygen species markedly improved oxygen migration rate as well as redox ability of the catalysts. Additionally, in situ diffuse reflectance infrared Fourier transform spectra showed that the absorbed toluene could be completely oxidized to CO2 and H2O with benzyl alcohol, benzaldehyde, benzoic acid, and maleic anhydride as intermediates. In summary, this study provided an alternative route for the synthesis of non-crystalline metal co-oxide nanofibers.

Engineered Fe-doped activated carbon from industry waste for peroxymonosulfate activation: Performance and mechanism

Efficient and low-cost catalysts are important for contaminant remediation in peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs). In this study, a solid waste, generated by the polyferric chloride coagulation of the phenol-saturated powder activated carbon from an industrial wastewater treatment plant, was used to prepare metal/carbon composites under different pyrolysis temperatures (650–950 °C). The catalyst pyrolyzed at 950 °C (FeAC-950) exhibited the highest reactive activity for PMS activation as demonstrated by a series of electrochemical techniques. Nearly complete BPA elimination can be achieved within 60 min by 0.1 g L–1 FeAC-950 and 0.5 mM PMS. The results of electron paramagnetic resonance (EPR), chemical quenching and open circuit potential (OCPT) experiments demonstrate a combined radical and non-radical oxidation mechanism in the FeAC-950/PMS process and BPA was removed dominantly through radical pathway. Various persistent organic pollutants can be efficiently eliminated in the FeAC-950/PMS system. In addition, the present system showed good tolerance to natural organic matter as well as some common anions such as chloride and nitrate. This study dedicated a simple method to prepare an efficient solid waste-based catalyst in environmental catalysis. The outcomes will not only provide a value-added reuse approach for waste management but also facilitate the FeAC-950 applications in wastewater remediation technologies.

PdIr nanoparticles on NH2-functionalized dendritic mesoporous silica nanospheres for efficient dehydrogenation of formic acid

Developing highly efficient solid catalysts for formic acid (HCOOH, FA) dehydrogenation is essential to utilize FA as a hydrogen (H2) carrier. In this work, ultrafine bimetallic PdIr nanoparticles (NPs) supported on the amine-functionalized dendritic mesoporous silica nanospheres (PdIr/DMSNs-NH2) have been successfully synthesized by the simple surface functionalization and co-reduction method. The optimized Pd4Ir1/DMSNs-NH2 (Pd/Ir molar ratio = 4:1) catalyst displayed the remarkable catalytic performance with 100 % H2 selectivity of the FA dehydrogenation, and the initial turnover frequency (TOF) could achieve 1333 h−1 with the additive of sodium formate (SF) at 298 K, which is comparable to the most effective mesoporous silica supported Pd-containing solid catalysts. The activation energy (Ea) for the FA dehydrogenation of Pd4Ir1/DMSNs-NH2 catalyst in the FA-SF mixture is 39.7 KJ/mol, lower than most reported catalysts. Furthermore, the optimized catalyst maintained 100 % H2 selectivity even after five runs, only with a negligible decrease in the activity, displaying the excellent stability of the catalyst. The superior catalytic performance could be attributed to the synergistic effect of open dendritic pore channel, high dispersion and ultrafine size of PdIr NPs as the active sites on DMSNs-NH2, and regulated electronic effects of Pd and Ir. More importantly, introducing –NH2 groups to the DMSNs could facilitate the O–H bond dissociation of FA and improve the FA dehydrogenation activity under mild conditions. This work will significantly promote FA as a hydrogen carrier on fuel cells.

Ce doping promote the selective conversion of ethanol to ethyl acetate via the dehydrogenation-condensation over CuCeZr catalyst

Ethyl acetate, as an important organic solvent, can be produced via ethanol dehydrogenation-condensation route with 96% atomic economy and environmental friendliness. Although CuZr-based catalysts have been widely used in this reaction, high ethyl acetate selectivity with satisfied ethanol conversion remains a great challenge. Herein, an efficient CuCeZr solid solution catalyst is developed and realize the selective synthesis of ethyl acetate from ethanol. The CuCeZr catalyst with 10 wt% Ce doping shows the highest selectivity (87.5%) and 55.9% ethanol conversion, which is superior to other reported CuZr-based catalysts. A 1000 h continuous life-test result indicates an excellent stability of CuCeZr catalyst. The characterization and reaction results suggest that the Ce doping enhanced the formation of Cu (I) species to improve the selectivity of ethyl acetate. Moreover, it decreases the amount of strong acid-base sites, which suppresses the self-condensation of acetaldehyde and dehydration process, reducing the production of C4 by-products.

Electrospun membranes of iron tailings toward peroxymonosulfate activation for efficient photocatalytic degradation of organic pollutants

Iron-based catalysts are considered to be an important and promising transition metal catalyst. However, although the developed iron-based catalysts have good catalytic activity for peroxymonosulfate (PMS), their complex synthesis process, high cost and difficult recovery limit their large-scale application. In this work, a high performance, environmentally friendly and easily recyclable catalyst was prepared by anchoring iron tailings into electrospun fibers (EF). The electrospun membranes of iron tailings (EF-iron tailings) could activate PMS for degradation of organic pollutants under visible light. During reaction process, visible light accelerated the valence state transition of iron, which was conducive to the activation of PMS. The degradation mechanism showed that hydroxyl radical (·OH), superoxide radical (·O2−) and singlet oxygen (1O2) were the main active species, and·O2− and 1O2 seemed to be more important for degradation. The application assessment in natural water confirmed potential practical application value of the EF-iron tailings membrane. The leaching test showed that the iron leaching amount of the EF-iron tailings membrane was low in the reaction process, meeting environmental requirements. This work provides an effective green preparation strategy of efficient solid waste-based catalyst with pro-environment and easy recycling.

Cost-Effective Biodiesel Synthesis from Waste Marble Powder as A Green Heterogeneous Catalyst Using Pongamia Pinnata Oil

Waste marble powder (WMP) is Investigated for developing heterogeneous catalysts by calcination method and used in biodiesel synthesis by esterification-transesterification process from Pongamia Pinnata oil. Hammet indicators, Fourier transform infrared (FT-IR), Thermogravimetric analysis, and X-ray powder diffraction (XRD) techniques were also studied for the characterization of developed catalyst from waste marble powder (WMP). The conversion of calcium carbonate to calcium oxide in marble powder was found at 800°C after calcination. The maximum biodiesel yield reached about 94% using a 3.5 wt% catalyst, 9:1 methanol to Pongamia pinnata oil molar ratio, and 2.5 hour process time at 65°C. The biodiesel purity was tested by gas chromatography analysis. The catalyst stability was tested by recyclability test and found a small decrease in biodiesel yield up to 5 recyclability runs. The solid heterogeneous catalyst from WMP proves that the harmful waste could be converted and used as an economically efficient solid heterogeneous catalyst for sustainable biodiesel production from Pongamia Pinnata oil.

A Green Route to Methyl Formate from CO2-Derived Formamides over Solid Base Catalysts

The transformation of CO2 and CO2-derived chemicals into high value-added chemicals is an important method for reducing CO2 emissions and achieving carbon neutrality. Methyl formate (MF) is a critical C1 building block in synthesizing a wide range of important chemicals, such as formic acid, ethylene glycol, and formamide methyl propionate. Here, we report a green route for the sustainable synthesis of MF from CO2-derived formamides via the alcoholysis reaction catalyzed by supported CaO solid bases. The CaO/MgO catalyst with 13.5 wt.% CaO exhibited higher alcoholysis reaction efficiency and achieved 94.5% conversion of N-formylmorpholine and 100% selectivity of MF in methanol at 120 °C. Based on the kinetic studies, characterization results of structural and basic properties (XRD, and TEM, CO2-TPD, etc.), we found that the density of strong basic sites is linearly related to the activity of alcoholysis reaction, and the higher the base density on these catalysts, the greater the reaction rate. This study presents a sustainable route for the synthesis of MF by using CO2-derived formamides and green methanol, and a promising strategy for producing more efficient solid alcoholysis catalysts of amides.

Ethanolysis of glucose into biofuel 5-ethoxymethyl-furfural catalyzed by NH4H2PO4 modified USY zeolite

5-Ethoxymethylfurfural (EMF) can be considered as a potential biofuel because of its excellent combustion properties, such as high energy density and low carbon smoke emissions. In this study, Ultra-stable Y (USY) zeolite was modified with NH4H2PO4 and then used as an efficient solid catalyst for the catalytic synthesis of EMF via ethanolysis of glucose First, the NH4H2PO4-modified USY was characterized by FT-IR, XRD, BET, and NH3-TPD. The effect of reaction temperature, reaction time, substrate concentration, and catalyst loading on the yield of EMF was investigated. The P0.2-USY optimal EMF yield was 39.6 mol%, which increased by 20.7% compared to USY, and still had better activity after being reused for 5 cycles. Moreover, the pseudo-homogeneous first-order kinetics model was developed to elucidate the kinetics of EMF formation from glucose, and the kinetics results showed that the activation energy of EMF formation (64.2 kJ⋅mol-1) was lower than that of humins formation (73.2 kJ⋅mol-1). Finally, the ethanolysis pathway was proposed based on the product distribution.

Low-cost diatomite supported binary transition metal sulfates: an efficient reusable solid catalyst for biodiesel synthesis.

Using a simple method of impregnation and then calcination, diatomite supported binary transition metal sulfates (Fe and Zr, designated as Fe2(SO4)3&Zr(SO4)2@diatomite) were prepared and used as a catalyst in the preparation of renewable biofuels. The synthesised Fe2(SO4)3&Zr(SO4)2@diatomite catalyst (Fe2(SO4)3 : Zr(SO4)2 : diatomite = 1 : 2 : 6, mass ratio) was thoroughly characterised using transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, microbeam X-ray fluorescence (μ-XRF) spectroscopy and thermogravimetric analysis (TG). The results demonstrated that the sulfate was successfully loaded onto the diatomite with a uniform distribution. The N2 adsorption/desorption analysis indicated that the catalyst's specific surface area was 1.54 m2 g-1. The catalyst exhibited outstanding performance in the preparation of renewable biofuel (biodiesel) from waste fatty acids and the optimal parameters were methanol-to-oil 1.25 : 1, reaction temperature 70 °C, catalyst concentration 10 wt%, reaction time 4 h. The conversion was found to reach 98.90% under optimal parameters, which is better than that of Fe2(SO4)3·xH2O, Zr(SO4)2·4H2O, Fe2(SO4)3@diatomite and Zr(SO4)2@diatomite. Moreover, the catalyst can be recycled by simple filtration and reused for three cycles after regeneration without noticeable reduction in catalytic activity.

Selective cycloaddition of ethylene oxide to CO2 within the confined space of an amino acid-based metal-organic framework.

Host-guest chemistry within the confined space of metal-organic frameworks (MOFs) offers an almost unlimited myriad of possibilities, hardly accessible with other materials. Here we report the synthesis and physical characterization, with atomic resolution by single-crystal X-ray diffraction, of a novel water-stable tridimensional MOF, derived from the amino acid S-methyl-L-cysteine, {SrZn6[(S,S)-Mecysmox]3(OH)2(H2O)}·9H2O (1), and its application as a robust and efficient solid catalyst for the cycloaddition reaction of ethylene/propylene oxide with CO2 to afford ethylene/propylene carbonate with yields of up to 95% and selectivity of up to 100%. These results nicely illustrate the great potential of MOFs to be game changers for the selective synthesis of industrially relevant products, representing a powerful alternative to the current heterogeneous catalysts.

Biodiesel production from quinary oil mixture using highly efficient Musa chinensis based heterogeneous catalyst

In this study, efficient solid catalysts from the post-harvest Musa chinensis peel, trunk and rhizome were prepared and applied effectively for the production of biodiesel from the quinary oil mixture (soybean oil, sunflower oil, canola oil, jatropha oil and pongamia oil). Catalyst characterization exhibited a highly basic character with the micro-mesoporous and polycrystalline nature of the material. This work investigated the effect of catalyst load, different catalysts from different parts of the plant, MRMO (molar ratio of methanol to oil) and temperature on the reaction. The calcined M. chinensis peel catalyst was found to be the best with 44.15 wt% of K occurring as its carbonate and oxide, which successfully yielded 95.82 % biodiesel at optimized conditions of 5 wt% catalyst amount and 9:1 MRMO at temperature of 65 °C in 11 min. The highest basicity was observed in calcined peel catalyst (0.93 mmol g−1) in comparison to that of trunk (0.15 mmol g−1) and rhizome catalysts (0.2 mmol g−1). This study also displayed a turnover frequency of 16.85 h−1 (peel), 7.025 h−1 (trunk) and 2.317 h−1 (rhizome). The activation energy of the quinary oil mixture-based biodiesel synthesis with the peel catalyst was 53.625 kJ mol−1. In this work, the catalyst was found to be highly effective, reusable and produced good quality biodiesel that conforms to the international standards, and thus, it may be considered a potential renewable catalyst for biodiesel industries.