COMPOSITE MATERIAL COMPRISING AN ELECTRIDE COMPOUND

Abstract

A process for preparing a composite material comprising an electride compound and an additive, said process comprising (i) providing a composition comprising the additive and a precursor compound of the electride compound, wherein the precursor compound comprises an oxidic compound of the garnet group, and wherein the additive has a boiling temperature which is higher than the melting temperature of the precursor compound; (ii) heating the composition provided in (i) under plasma forming conditions in a gas atmosphere to a temperature above the Httig temperature of the precursor compound and below the boiling temperature of the additive, obtaining the composite material.

Claims

1-20. (canceled)

21. A process for preparing a composite material comprising an electride compound and an additive, said process comprising (i) providing a composition comprising the additive and a precursor compound of the electride compound, wherein the precursor compound comprises an oxidic compound of the garnet group, and wherein the additive has a boiling temperature which is higher than the melting point of the precursor compound; (ii) heating the composition provided in (i) under plasma forming conditions in a gas atmosphere to a temperature above the Httig temperature of the precursor compound and below the boiling temperature of the additive, obtaining the composite material.

22. The process of claim 21, wherein according to (ii), heating the composition under plasma forming conditions comprises heating the composition in an electric arc, wherein according to (ii), the composition provided in (i) is heated to a temperature above the Tamman temperature of the precursor compound and below the boiling temperature of the additive, preferably Wherein according to (ii), the composition provided in (i) is heated to a temperature above the melting temperature of the precursor compound and below the boiling temperature of the additive.

23. The process of claim 21, wherein the oxidic compound of the garnet group according to (i) comprises aluminum and/or calcium.

24. The process of claim 21, wherein at least 90 weight-% of the precursor compound consist of an oxidic compound of the garnet group.

25. The process of claim 21, comprising (i) providing a composition comprising the additive and a precursor compound of the electride compound, Wherein the precursor compound comprises an oxidic compound of the garnet group, and wherein the additive has a boiling temperature which is higher than the melting point of the precursor compound; (ii) heating the composition provided in (i) in an electric arc in a gas atmosphere to a temperature above the Httig temperature of the precursor compound and below the boding temperature of the additive, obtaining the electride compound.

26. The process of claim 21, wherein providing the composition according to (i) comprises (i.1) providing the precursor compound and providing the additive; (i.2) preparing the composition comprising the additive and the precursor compound provided in (i.1); wherein in the composition provided in (i), the weight ratio of the precursor compound relative to the additive is in the range of from 0.01:1 to 1000:1 (i.1.1).

27. The process of claim 26, wherein the source of calcium is one or more of a calcium oxide, a calcium hydroxide, a hydrated calcium oxide, and a calcium carbonate, and the source of aluminum is one or more of an aluminum hydroxide including one or more of gibbsite, hydrargillite, bayerite, doyleite, nordstrandite, and gel-like amorphous aluminum hydroxide, an aluminum oxyhydroxide including one or more of pseudo-boehmite, boehmite, diaspor, and akdalaite, and an aluminum oxide including one or more of gamma aluminum oxide, chi aluminum oxide, delta aluminum oxide, eta aluminum oxide, rho aluminum oxide and kappa aluminum oxide.

28. The process of claim 26, wherein according to (i.1.3), the mixture is calcined in a gas atmosphere, wherein the gas atmosphere comprises oxygen.

29. The process of claim 26, wherein preparing the composition according to (i.2) comprises mixing the additive with the precursor compound.

30. The process of claim 21, wherein the additive has a boiling temperature which is at least 20 C. higher than the melting temperature of the precursor compound.

31. The process of claim 21, wherein the additive comprises a metal compound, a semi-metal compound or a non-metal compound which is an oxygen getter material reducing the oxygen partial pressure during heating under plasma conditions according to (ii).

32. The process of claim 21, wherein the additive is in the form of a molding.

33. The process of claim 21, wherein the heating according to (ii) is carried out in an electric arc furnace which comprises a first electrode and a second electrode between which the electric arc is formed, wherein on the second electrode, the composition to be heated is positioned, and wherein during heating according to (ii), the electrical power of the light arc between the first electrode and the second electrode is in the range of from 100 to 4000 W.

34. The process of claim 21, wherein according to (ii), the composition is heated under plasma forming conditions for a period of time in the range of from 1 to 350 s.

35. The process of claim 21, wherein heating the composition provided in (i) under plasma forming conditions according to (ii) is carried out under oxygen (O.sub.2) removal conditions, wherein the oxygen removal conditions comprise physical oxygen removal conditions and/or chemical oxygen removal conditions.

36. The process of claim 35, wherein the chemical oxygen removal conditions comprise a gas atmosphere according to (ii) which comprises an oxygen reducing gas, and wherein the gas atmosphere according to (ii) comprises a gas which is ionizable under the plasma forming conditions according to (ii).

37. The process of claim 35, wherein the physical oxygen removal conditions comprise (ii.1) heating the composition provided in (i) in the gas atmosphere under plasma forming conditions for a period of time delta.sub.1t, wherein the gas atmosphere comprises a gas which is ionizable under the plasma forming; (ii.2) at least partially removing the gas atmosphere after the period of time delta.sub.1t and providing a fresh gas atmosphere comprising a gas which is ionizable under the plasma forming conditions; (ii.3) further heating of the composition obtained from (ii.2) in the fresh gas atmosphere under plasma forming conditions for a period of time delta.sub.2t

38. A composite material comprising an electride compound and an additive, obtained by the process according to claim 21.

39. A composite material comprising an electride compound and an additive, wherein the additive comprises an element of group IIIA or group IVA of the periodic table; wherein the electride compound is obtained from an oxidic compound of the garnet group as defined in claim 23 by heating under plasma forming conditions; wherein the composite material exhibits one or more of a BET specific surface area in the range of from 2 to 1000 m.sup.2/g; an XRD pattern comprising a 211 reflection and a 420 reflection; an EPR spectrum comprising resonances in the range of from 335 to 345 mT.

40. Use of a composite material according to claim 38 as a catalyst or a catalyst component.

Description

SHORT DESCRIPTION OF THE FIGURES

[0289] FIG. 1 shows a schematic drawing illustrating the general principle of the electric arc furnace described in Reference Example 1.1. In particular, [0290] 1 stands for the electric furnace recipient [0291] 2 stand for the tungsten electrode (cathode) [0292] 3 stands for the water-cooled copper anode [0293] 4 shows the distance between cathode and anode (about 20 mm) [0294] 5 shows the diameter of the anode (101 mm) [0295] 6 shows the height of tungsten electrode (63 mm) [0296] 7 shows the height of the housing (158 mm) [0297] 8 stands for the housing

[0298] FIG. 2 shows a schematic drawing illustrating the general principle of the electric arc furnace described in Reference Example 1.1. In particular, [0299] 1 stands for the electric furnace recipient [0300] 2 shows the connection to a vacuum pump [0301] 3 shows the connection to a gas reservoir (e.g. for Ar or for Ar/H.sub.2) [0302] 4 shows an air vent

[0303] FIG. 3 shows the linear correlation of the apparatus settings (intensity levels) and the corresponding electric power for two different gas atmospheres in the electric arc furnace.

[0304] FIG. 4 shows the XRD pattern of the oxidic compound prepared according to Example 1.

[0305] FIG. 5 shows the XRD pattern of the composite material prepared according to Example 3.

[0306] FIG. 6 shows the EPR spectrum of the composite material prepared according to Example 3.

[0307] FIG. 6a shows the EPR spectra of the composite materials prepared according to Example 3a, showing the g values.

[0308] FIG. 6b shows the Kubelka-Munk transformed absorption spectra of the composite material comprising an electride compound based on mayenite and comprising graphite, prepared according to Example 3b.

[0309] FIG. 7 shows the XRD pattern of the composite material prepared according to Example 4.

[0310] FIG. 8 shows the beta SiC extrudates used according to Example 5.1

[0311] FIG. 9 shows a beta SiC sphere used according to Example 5.2

[0312] FIG. 10 shows the beta SiC foam used according to Example 6.1

[0313] FIG. 11 shows the XRD pattern of the composite material prepared according to Example 6.2.

CITED PRIOR ART

[0314] Y. Nishio, K. Nomura, M. Miyakawa, K. Hayashi, H. Yanagi, T. Kamiya, M. Hirano and H. Hosono, Fabrication and transport properties of 12CaO.7Al2O3 (C12A7) electride nanowire, Phys. Stat. Sol. (A) (Physica Status Solidi (A)), 2008, pp 2047-2051 [0315] J. L. Dye, Electrons as Anions, Science, 2003, pp 607-608 [0316] J. L. Dye, Electrides: early examples of quantum confinement, Acc Chem Res, 2009, pp 1564-1572 [0317] US 2006/0151311 A1 [0318] US 2009/0224214 A1 [0319] US 2015/0217278 A1 [0320] E. S. Grew et al., American Mineralogist, vol. 98, 2013, pp 785-211