Abstract Ball-milled Ti–B-doped sodium aluminum hydride was directly synthesized via mechanical ball-milling of a NaH/Al mixture. The mixture was completely hydrogenated to NaAlH4 after 70 h under hydrogen pressure of 1 MPa. And higher hydrogen pressure is beneficial for the conversion from NaH/Al mixture to NaAlH4. The …

dehydrogenation. A second common reaction is the oxidative cleavage of carbon-carbon double bonds.This was observed with the formation of camphenilone from camphene and the genera-tion of two keto aldehydes by cleavage of the double bonds ln a-terpinene (Figure 2). Smog chamber studies on numer-ous terpenes using ozone and/or hydroxyl …

TY - JOUR T1 - Solvent-free dehydrogenation of γ-terpinene in a ball mill: investigation of reaction parameters A1 - Szuppa, Tony A1 - Stolle, Achim A1 - Ondruschka, Bernd A1 - …

The scale-up of the Knoevenagel-condensation between vanillin and barbituric acid carried out in planetary ball mills is investigated from an engineering perspective and results indicate that the optimal value is roughly 50% of the total milling beakers' volume, VB,total, independent of the reaction scale or reaction conditions. The …

laboratory ball mills.4a Within this work we take a closer look at the solvent-free oxidation of g-terpinene (1)top-cymene (2; Scheme 1) enhanced by grinding in a planetary ball mill. The selective synthesis of 2 is a poorly investigated area of chemical research. Predominantly, 2 plays a major role as a by-product during the isomerization of ...

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The dehydrogenation of γ-terpinene was studied under catalyst- and solvent-free reaction conditions using air as an oxidant. The dehydrogenation affords p …

The aerobic dehydrogenation of cheaply available para-menthenic terpenes, i.e., γ-terpinene, α-terpinene, limonene, and terpinolene, to commercially more valuable p-cymene has been developed.The reaction is catalyzed by p-benzoquinone and occurs in acetic acid solutions under relatively mild conditions (80–100 °C, 5–10 atm).In …

The decreased dehydrogenation temperature and improved dehydrogenation kinetics were achieved by high-energy ball milling Mg(AlH 4) 2.The particle size, grain size, microstrain and lattice distortion of the post-milled samples, i.e., from macro- to micro-scale, were systematically characterized by means of SEM and …

140 h in a planetary ball mill (QM-ISP2). 2.2 Preparation of samples About 1.6 g mixture of NaH (97.0 wt%), Al powder ... Reaction (1) at the temperature of about 100 C. In addi-tion, the second dehydrogenation step starts at 172.2 C and completes at about 233.7 C. Approximately 4.15 wt% H 2 (Fig. 4b) is released from ball-milled Ti–B-doped

Abstract: V 2 O 5 /NiO catalysts were prepared by a solid phase ball milling method using NiO and V 2 O 5 calcined at different temperatures as precursors.The influence of precursor calcination temperature on the catalytic performance of the V 2 O 5 /NiO catalysts for oxidative dehydrogenation of propane to propene was investigated. The catalysts were …

The present article reports on the solvent-free dehydrogenation of γ-terpinene (1) in a planetary ball mill affording p-cymene (2) as the predominant reaction product.

dehydrogenation of γ-terpinene to -cymene [p 10] and the oxidative cleavage of β-pinene affording nopinone [11]. Especially the last example proved to be a real alternative for ... Ball Mills with respect to organic synthesis are significantly influenced by process parameters like operating frequency andreaction time [2,9-11]. Correlation of ...

Using a novel ball mill with controlled ball movement, titanium and zirconium nitrides were synthesized by simple milling, at room temperature, of titanium and zirconium elemental powders in … Expand

The dehydrogenation of γ-terpinene was studied under catalyst- and solvent-free reaction conditions using air as an oxidant. The dehydrogenation affords p-cymene in good yields in a continuous flow reaction setup.The initial optimization of the reaction parameters showed that the dehydrogenation is highly dependent on the vapour/liquid phase …

The present article reports on the solvent-free dehydrogenation of γ-terpinene (1) in a planetary ball mill affording p-cymene (2) as the predominant reaction product. …

Magnesium-based hydrogen storage materials are considered to be one of the most promising solid-state hydrogen storage materials due to their large hydrogen storage capacity and low cost. However, slow hydrogen …

The present article reports on the solvent-free dehydrogenation of g-terpinene (1) in a planetary ball mill affording p-cymene (2) as the predominant …

CoFe 2 O 4 nanoparticles significantly reduce the MgH 2 desorption temperature, compared with the un-doped sample. The dehydrogenation process of MgH 2 doped with 3 mol% CoFe 2 O 4 initiates at about 200 °C. For the 5 mol% CoFe 2 O 4 doped sample, the dehydrogenation process proceeds at 180 °C. Further increase of …

Ball Mills are apparatus designed for the refinement of particles or desagglomeration of aggregated species. Thus, ball milling is a valuable technology for up- and down-stream …

A new, ligand- and solvent-free method for the Huisgen 1,3-dipolar cycloaddition (click reaction) was developed using a planetary ball mill, and a propargyl functionalized polymer was converted by mill clicking. A new, ligand- and solvent-free method for the Huisgen 1,3-dipolar cycloaddition (click reaction) was developed using a planetary ball mill. Besides …

A ball mill also known as pebble mill or tumbling mill is a milling machine that consists of a hallow cylinder containing balls; mounted on a metallic frame such that it can be rotated along its longitudinal axis. The balls which could be of different diameter occupy 30 – 50 % of the mill volume and its size depends on the feed and mill size. ...

The present article reports on the solvent-free dehydrogenation of γ-terpinene (1) in a planetary ball mill affording p-cymene (2) as the predominant …

The dehydrogenation of y-terpinene was studied under catalyst- and solvent-free reaction conditions using air as an oxidant. The dehydrogenation affords p-cymene in good yields in a...

Reaction parameters for oxidative dehydrogenation of γ-terpinene 9 to p-cymene 10 were studied in great detail by Stolle et al. (Scheme 6.4) [5]. It was found that potassium permanganate is the most efficient oxidant in mechanochemical reaction. ... Alumina was used as milling auxiliary in planetary ball mill Pulverisette, with ZrO 2 milling ...

The present article reports on the solvent-free dehydrogenation of γ-terpinene (1) in a planetary ball mill affording p-cymene (2) as the predominant reaction product.

The dehydrogenation of γ-terpinene was studied under catalyst- and solvent-free reaction conditions using air as an oxidant. ... The present article reports on the solvent-free dehydrogenation of γ-terpinene (1) in a planetary ball mill affording p-cymene (2) as the predominant reaction product. The influence of various … Expand. 63. PDF.

The present article reports on the solvent-free dehydrogenation of γ-terpinene (1) in a planetary ball mill affording p-cymene (2) as the predominant reaction product.The influence of various reaction parameters and technical variables on the transformation of 1 has been assessed. Thus, it is shown that KMnO 4 can be substituted by other, less …

The blank tests have shown small wt.% changes of the order of ~0.01e0.05 wt.%. Results Dehydrogenation The effect of ball-milling time on the dehydrogenation behaviour of the NaAlH4eMgH2 (1:1) mixture is shown in Fig. 1. Prolonged ball-milling (30e360 min) has an effect on the dehydrogenation reaction rates.

Following the rehydrogenation under 6 MPa hydrogen pressure at 350 C after the first complete dehydrogenation, the second dehydrogenation of the sample is carried out. Fig. 9 exhibits the first dehydrogenation and the second dehydrogenation curves of the ball-milled MgH2 doped with 7 mol% nanosized CoFe2O4 and the same amount of the …