Preparation and catalytic properties of cobalt salts of Keggin type heteropolyacids supported on mesoporous silica

Popa, Alexandru; Sasca, Viorel; Verdeş, Orsina; Oszkó, A.

doi:10.1016/j.cattod.2017.02.045

Cited by 15 publications

(12 citation statements)

References 45 publications

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“…[36] The Mo 3d spectrum is deconvoluted into 2 doublets at 232.6 eV and 233.45 eV, which are contributing to Mo 6 + in MoO 3 existed in the keggin anion and more electropositive surrounded Mo 6 + , respectively. [37] The broad peak between 515 and 521 eV assigned to V 2p3/2 of all samples is deconvoluted to V 5 + and V 4 + species at 517.8 � 0.1 and 516 � 0.1 eV, respectively. V 5 + is the dominate unit of Keggin structure with existence of less V 4 + due to the redox equilibrium at the surface of catalyst.…”

Section: Resultsmentioning

confidence: 93%

“…The peaks at 135 eV and 134 eV are corresponding to P 2p1/2 and P 2p3/2, indicating that P(V) is existed in the HPAs [36] . The Mo 3d spectrum is deconvoluted into 2 doublets at 232.6 eV and 233.45 eV, which are contributing to Mo 6+ in MoO 3 existed in the keggin anion and more electropositive surrounded Mo 6+ , respectively [37] . The broad peak between 515 and 521 eV assigned to V 2p3/2 of all samples is deconvoluted to V 5+ and V 4+ species at 517.8±0.1 and 516±0.1 eV, respectively.…”

Section: Resultsmentioning

confidence: 99%

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Keggin‐type Heteropolyacids‐Catalyzed Selective Hydrothermal Oxidation of Microalgae for Low Nitrogen Biofuel Production

Shen

Long

et al. 2020

ChemSusChem

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Hydrothermal liquefaction (HTL) of microalgae for biofuel production is suffering from low bio-oil yield and high heteroatomic compositions owing to their low efficiency and selectivity to hydrolysis of cellular compounds. Hereby we report Keggin-type (MoÀ VÀ P) heteropolyacids (HPAs)-catalyzed HTL of microalgae for efficient low-nitrogen biocrude production. The increases of reaction temperature, reaction time, and vanadium substitution degrees of HPAs are favorable to biocrude yield initially, whereas a significant decrease of biocrude yield is observed owing to the enhanced oxidation of carbohydrates above the optimum reaction conditions. The maximum biocrude yield of HPAs-catalyzed HTL of microalgae is 29.95 % at reaction temperature of 300°C, reaction time of 2 h, and 5 wt% of HPA-4, which is about 19.66 % higher than that of control with 71.17 % less N-containing compounds, including 1,3-propanediamine, 1-pentanamine, and 2, 2'heptamethylene-di-2-imidazoline than that of control. This work reveals that HPAs with Brønsted acidity and reversible redox properties are capable of both enhancing biocrude production via catalyzing the hydrolysis of cellular compounds and reducing their nitrogen content through avoiding the Maillard reactions between the intermediates of hydrolysis of carbohydrates and proteins. HPAs-catalyzed HTL is an efficient strategy to produce low N-containing biofuels, possibly paving the way of their direct use in modern motors.

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Section: Resultsmentioning

confidence: 93%

Section: Resultsmentioning

confidence: 99%

Keggin‐type Heteropolyacids‐Catalyzed Selective Hydrothermal Oxidation of Microalgae for Low Nitrogen Biofuel Production

Shen

Long

et al. 2020

ChemSusChem

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“…The high conversion rate of 1-butanol and the selectivity of butenes indicated that Zn-Mn-Co/γ-Al 2 O 3 exhibited excellent activity at low temperature. Zinc, manganese, and cobalt oxides exhibited high activity in alcohol dehydration, as already proven [15][16][17]29]. The modification of metal ions improved the acidity of the catalyst, and the Lewis acid sites played an important role in the catalytic dehydration of alcohols [30].…”

Section: Catalytic Activity Of γ-Al2o3 and Zn-mn-co/γ-al2o3mentioning

confidence: 52%

“…WHSV mainly affected the retention time of 1-butanol in the catalyst micro-reactor system, and high WHSV was not conducive to the adsorption of butanol by a catalyst, which resulted in a decline of the conversion rate of 1-butanol. Zinc, manganese, and cobalt oxides exhibited excellent catalytic activity in the dehydration reaction of alcohol [15][16][17] and they are also used as active components to be loaded onto a catalyst carrier [16,19]. In this study, zinc, manganese, and cobalt were loaded onto γ-Al 2 O 3 , and the modified catalyst showed superior catalytic activity, which was attributed to the catalytic ability of the active components and the increase of the catalyst's acidity.…”

Section: Optimization Of Temperature and Whsv For Butanol Dehydrationmentioning

confidence: 88%

“…It has been proven that there is more dibutylether than butenes in the products when the reaction temperature is below 310 • C, and, as the temperature rises, butenes supersede dibutylether [14]. Transition metal catalysts such as cobalt [15,16], manganese, iron [17], nickel [18], and zinc oxides [19] are often utilized for the alcohol dehydration reaction. Metal-loaded catalysts with high catalytic activity and low cost are more adaptable to industrialization requirements.…”

Section: Introductionmentioning

confidence: 99%

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Efficient Catalytic Dehydration of High-Concentration 1-Butanol with Zn-Mn-Co Modified γ-Al2O3 in Jet Fuel Production

Liu

Yan

et al. 2019

Catalysts

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It is important to develop full-performance bio-jet fuel based on alternative feedstocks. The compound 1-butanol can be transformed into jet fuel through dehydration, oligomerization, and hydrogenation. In this study, a new catalyst consisting of Zn-Mn-Co modified γ-Al2O3 was used for the dehydration of high-concentration 1-butanol to butenes. The interactive effects of reaction temperature and butanol weight-hourly space velocity (WHSV) on butene yield were investigated with response surface methodology (RSM). Butene yield was enhanced when the temperature increased from 350 °C to 450 °C but it was reduced as WHSV increased from 1 h−1 to 4 h−1. Under the optimized conditions of 1.67 h−1 WHSV and 375 °C reaction temperature, the selectivity of butenes achieved 90%, and the conversion rate of 1-butanol reached 100%, which were 10% and 6% higher, respectively, than when using unmodified γ-Al2O3. The Zn-Mn-Co modified γ-Al2O3 exhibited high stability and a long lifetime of 180 h, while the unmodified γ-Al2O3 began to deactivate after 60 h. Characterization with X-ray diffraction (XRD), nitrogen adsorption-desorption, pyridine temperature-programmed desorption (Py-TPD), pyridine adsorption IR spectra, and inductively coupled plasma atomic emission spectrometry (ICP-AES), showed that the crystallinity and acid content of γ-Al2O3 were obviously enhanced by the modification with Zn-Mn-Co, and the loading amounts of zinc, manganese, and cobalt were 0.54%, 0.44%, and 0.23%, respectively. This study provides a new catalyst, and the results will be helpful for the further optimization of bio-jet fuel production with a high concentration of 1-butanol.

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How the Content of Protons and Vanadium Affects the Activity of H3+nPMo12-nVnO40 (n = 0, 1, 2, or 3) Catalysts on the Oxidative Esterification of Benzaldehyde with Hydrogen Peroxide

Silva

Ribeiro²,

Vilanculo

2022

Catal Lett

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Preparation and catalytic properties of cobalt salts of Keggin type heteropolyacids supported on mesoporous silica

Cited by 15 publications

References 45 publications

Keggin‐type Heteropolyacids‐Catalyzed Selective Hydrothermal Oxidation of Microalgae for Low Nitrogen Biofuel Production

Keggin‐type Heteropolyacids‐Catalyzed Selective Hydrothermal Oxidation of Microalgae for Low Nitrogen Biofuel Production

Efficient Catalytic Dehydration of High-Concentration 1-Butanol with Zn-Mn-Co Modified γ-Al2O3 in Jet Fuel Production

How the Content of Protons and Vanadium Affects the Activity of H3+nPMo12-nVnO40 (n = 0, 1, 2, or 3) Catalysts on the Oxidative Esterification of Benzaldehyde with Hydrogen Peroxide

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