1. A catalyst comprising an oxide of a rare earth element, the catalyst comprising:
the formula Ln14-xLn2xO6, wherein Ln1 and Ln2 are each independently a different lanthanide element, and x is a number ranging from greater than 0 to less than 4; and
at least one doping element from groups 1-16, lanthanides, actinides or combinations thereof,
wherein the catalyst further comprises a C2 selectivity of greater than 50% and a methane conversion of greater than 20% when the catalyst is employed as a heterogeneous catalyst in the oxidative coupling of methane at a temperature of 750\xb0 C. or less.
2. The catalyst of claim 1, wherein the at least one doping element is selected from groups 1-4, 8, 13, 14, lanthanides, actinides and combinations thereof.
3. The catalyst of claim 1, wherein the at least one doping element is selected from groups 1-6, 8, 11, 13-15, lanthanides, actinides and combinations thereof.
4. The catalyst of claim 1, wherein the at least one doping element is a rare earth element.
5. The catalyst of claim 1, wherein the at least one doping element is Na, Mg, Ca, Sr, Ga, Sc, Y, Zr, In, Nd, Eu, Sm, Ce, Gd, Hf, Ho, Tm, W, La, K, Dy, In, Cs, S, Zn, Rb, Ba, Yb, Ni, Lu, Ta, P, Pt, Bi, Sn, Nb, Sb, Ge, Ag, Au, Pb, Re, Fe, Al, Tl, Pr, Co, Rh, Ti, V, Cr, Mn, Ir, As, Li, Tb, Er, Te or Mo.
6. The catalyst of claim 1, wherein the catalyst comprises a combination of at least two different doping elements.
7. The catalyst of claim 6, wherein the two different doping elements are selected from Na, Mg, Ca, Sr, Ga, Sc, Y, Zr, In, Nd, Eu, Sm, Ce, Gd, Hf, Ho, Tm, W, La, K, Dy, In, Cs, S, Zn, Rb, Ba, Yb, Ni, Lu, Ta, P, Pt, Bi, Sn, Nb, Sb, Ge, Ag, Au, Pb, Re, Fe, Al, Tl, Pr, Co, Rh, Ti, V, Cr, Mn, Ir, As, Li, Tb, Er, Te and Mo.
8. The catalyst of claim 6, wherein the combination of at least two different doping elements is LaNd, LaSm, LaCe, LaSr, EuNa, EuGd, CaNa, EuSm, EuSr, MgSr, CeMg, GdSm, SrW, SrTa, AuRe, AuPb, BiHf, SrSn or MgN, CaS, RbS, SrNd, EuY, MgNd, SrNa, NdMg, LaMg, YbS, MgNa, SrW, KLa, KNa, LiCs, LiNa, ZnK, LiK, RbHf, CaCs, HfBi, SrSn, SrW, SrNb, ZrW, YW, NaW, BiW, BiCs, BiCa, BiSn, BiSb, GeHf, HfSm, SbAg, SbBi, SbAu, SbSm, SbSr, SbW, SbHf, SbYb, SbSn, YbAu, YbTa, YbW, YbSr, YbPb, YbW, YbAg, AuSr, WGe, TaHf, WAu, CaW, AuRe, SmLi, LaK, ZnCs, ZrCs, CaCe, LiSr, CsZn, DyK, LaMg, InSr, SrCs, GaCs, LuFe, SrTm, LaDy, MgK, ZrK, LiCs, SmCs, InK, LuTl, PrZn, LuNb, NaPt, NaCe, BaTa, CuSn, AgAu, AlBi, AlMo, AlNb, AuPt, GaBi, MgW, PbAu, SnMg, ZnBi, GdHo, ZrBi, HoSr, CaSr, SrPb or SrHf.
9. The catalyst of claim 1, wherein the catalyst comprises a combination of at least three different doping elements.
10. The catalyst of claim 9, wherein the three different doping elements are selected from Na, Mg, Ca, Sr, Ga, Sc, Y, Zr, In, Nd, Eu, Sm, Ce, Gd, Hf, Ho, Tm, W, La, K, Dy, In, Cs, S, Zn, Rb, Ba, Yb, Ni, Lu, Ta, P, Pt, Bi, Sn, Nb, Sb, Ge, Ag, Au, Pb, Re, Fe, Al, Tl, Pr, Co, Rh, Ti, V, Cr, Mn, Ir, As, Li, Tb, Er, Te and Mo.
11. The catalyst of claim 1, wherein the catalyst comprises a combination of at least four different doping elements.
12. The catalyst of claim 11, wherein the four different doping elements are selected from Na, Mg, Ca, Sr, Ga, Sc, Y, Zr, In, Nd, Eu, Sm, Ce, Gd, Hf, Ho, Tm, W, La, K, Dy, In, Cs, S, Zn, Rb, Ba, Yb, Ni, Lu, Ta, P, Pt, Bi, Sn, Nb, Sb, Ge, Ag, Au, Pb, Re, Fe, Al, Tl, Pr, Co, Rh, Ti, V, Cr, Mn, Ir, As, Li, Tb, Er, Te and Mo.
13. The catalyst of claim 1, wherein Ln1 or Ln2 is lanthanum.
14. The catalyst of claim 1, wherein Ln1 or Ln2 is neodymium.
15. The catalyst of claim 1, wherein Ln1 or Ln2 is ytterbium.
16. The catalyst of claim 1, wherein Ln1 or Ln2 is europium.
17. The catalyst of claim 1, wherein Ln1 or Ln2 is samarium.
18. The catalyst of claim 1, wherein Ln1 or Ln2 is cerium.
19. The catalyst of claim 1, wherein Ln1 or Ln2 is praseodymium.
20. A catalyst comprising an oxide of a rare earth element, wherein the oxide of a rare earth element is a metal oxyhydroxide, metal oxyhalide, a metal oxynitrate or a metal phosphate, wherein the catalyst further comprises at least one doping element from groups 1-16, lanthanides, actinides or combinations thereof, wherein the catalyst comprises a C2 selectivity of greater than 50% and a methane conversion of greater than 20% when the catalyst is employed as a heterogeneous catalyst in the oxidative coupling of methane at a temperature of 750\xb0 C. or less.
21. The catalyst of claim 20, wherein the at least one doping element is selected from groups 1-4, 8, 13, 14, lanthanides, actinides and combinations thereof.
22. The catalyst of claim 20, wherein the at least one doping element is selected from groups 1-6, 8, 11, 13-15, lanthanides, actinides and combinations thereof.
23. The catalyst of claim 20, wherein the at least one doping element is a rare earth element.
24. The catalyst of claim 20, wherein the at least one doping element is Na, Mg, Ca, Sr, Ga, Sc, Y, Zr, In, Nd, Eu, Sm, Ce, Gd, Hf, Ho, Tm, W, La, K, Dy, In, Cs, S, Zn, Rb, Ba, Yb, Ni, Lu, Ta, P, Pt, Bi, Sn, Nb, Sb, Ge, Ag, Au, Pb, Re, Fe, Al, Tl, Pr, Co, Rh, Ti, V, Cr, Mn, Ir, As, Li, Tb, Er, Te or Mo.
25. The catalyst of claim 20, wherein the catalyst comprises a combination of at least two different doping elements.
26. The catalyst of claim 25, wherein the two different doping elements are selected from Na, Mg, Ca, Sr, Ga, Sc, Y, Zr, In, Nd, Eu, Sm, Ce, Gd, Hf, Ho, Tm, W, La, K, Dy, In, Cs, S, Zn, Rb, Ba, Yb, Ni, Lu, Ta, P, Pt, Bi, Sn, Nb, Sb, Ge, Ag, Au, Pb, Re, Fe, Al, Tl, Pr, Co, Rh, Ti, V, Cr, Mn, Ir, As, Li, Tb, Er, Te and Mo.
27. The catalyst of claim 25, wherein the combination of at least two different doping elements is LaNd, LaSm, LaCe, LaSr, EuNa, EuGd, CaNa, EuSm, EuSr, MgSr, CeMg, GdSm, SrW, SrTa, AuRe, AuPb, BiHf, SrSn or MgN, CaS, RbS, SrNd, EuY, MgNd, SrNa, NdMg, LaMg, YbS, MgNa, SrW, KLa, KNa, LiCs, LiNa, ZnK, LiK, RbHf, CaCs, HfBi, SrSn, SrW, SrNb, ZrW, YW, NaW, BiW, BiCs, BiCa, BiSn, BiSb, GeHf, HfSm, SbAg, SbBi, SbAu, SbSm, SbSr, SbW, SbHf, SbYb, SbSn, YbAu, YbTa, YbW, YbSr, YbPb, YbW, YbAg, AuSr, WGe, TaHf, WAu, CaW, AuRe, SmLi, LaK, ZnCs, ZrCs, CaCe, LiSr, CsZn, DyK, LaMg, InSr, SrCs, GaCs, LuFe, SrTm, LaDy, MgK, ZrK, LiCs, SmCs, InK, LuTl, PrZn, LuNb, NaPt, NaCe, BaTa, CuSn, AgAu, AlBi, AlMo, AlNb, AuPt, GaBi, MgW, PbAu, SnMg, ZnBi, GdHo, ZrBi, HoSr, CaSr, SrPb or SrHf.
28. The catalyst of claim 20, wherein the catalyst comprises a combination of at least three different doping elements.
29. The catalyst of claim 28, wherein the three different doping elements are selected from Na, Mg, Ca, Sr, Ga, Sc, Y, Zr, In, Nd, Eu, Sm, Ce, Gd, Hf, Ho, Tm, W, La, K, Dy, In, Cs, S, Zn, Rb, Ba, Yb, Ni, Lu, Ta, P, Pt, Bi, Sn, Nb, Sb, Ge, Ag, Au, Pb, Re, Fe, Al, Tl, Pr, Co, Rh, Ti, V, Cr, Mn, Ir, As, Li, Tb, Er, Te and Mo.
30. The catalyst of claim 20, wherein the catalyst comprises a combination of at least four different doping elements.
31. The catalyst of claim 30, wherein the four different doping elements are selected from Na, Mg, Ca, Sr, Ga, Sc, Y, Zr, In, Nd, Eu, Sm, Ce, Gd, Hf, Ho, Tm, W, La, K, Dy, In, Cs, S, Zn, Rb, Ba, Yb, Ni, Lu, Ta, P, Pt, Bi, Sn, Nb, Sb, Ge, Ag, Au, Pb, Re, Fe, Al, Tl, Pr, Co, Rh, Ti, V, Cr, Mn, Ir, As, Li, Tb, Er, Te and Mo.
32. The catalyst of claim 20, wherein the oxide of a rare earth element is a lanthanum oxyhydroxide, a lanthanum oxyhalide, a lanthanum oxynitrate or a lanthanum phosphate.
33. The catalyst of claim 20, wherein the oxide of a rare earth element is a neodymium oxyhydroxide, a neodymium oxyhalide, a neodymium oxynitrate or a neodymium phosphate.
34. The catalyst of claim 20, wherein the oxide of a rare earth element is a ytterbium oxyhydroxide, a ytterbium oxyhalide, a ytterbium oxynitrate or a ytterbium phosphate.
35. The catalyst of claim 20, wherein the oxide of a rare earth element is a europium oxyhydroxide, a europium oxyhalide, a europium oxynitrate or a europium phosphate.
36. The catalyst of claim 20, wherein the oxide of a rare earth element is a samarium oxyhydroxide, a samarium oxyhalide, a samarium oxynitrate or a samarium phosphate.
37. The catalyst of claim 20, wherein the oxide of a rare earth element is a yttrium oxyhydroxide, a yttrium oxyhalide, a yttrium oxynitrate or a yttrium phosphate.
38. The catalyst of claim 20, wherein the oxide of a rare earth element is a cerium oxyhydroxide, a cerium oxyhalide, a cerium oxynitrate or a cerium phosphate.
39. The catalyst of claim 20, wherein the oxide of a rare earth element is a praseodymium oxyhydroxide, a praseodymium oxyhalide, a praseodymium oxynitrate or a praseodymium phosphate.
40. The catalyst of claim 1 or claim 20, wherein the oxidative coupling of methane is performed at total reaction pressures ranging from 1 atm to 10 atm.
41. The catalyst of claim 1 or claim 20, wherein the C2 selectivity is greater than 60% when the catalyst is employed as a heterogeneous catalyst in the oxidative coupling of methane at a temperature of 750\xb0 C. or less.
42. The catalyst of claim 1 or claim 20, wherein the C2 yield is greater than 10% when the catalyst is employed as a heterogeneous catalyst in the oxidative coupling of methane at a temperature of 750\xb0 C. or less.
43. The catalyst of claim 1 or claim 20, wherein the oxidative coupling of methane is performed at a temperature of 700\xb0 C. or less.
44. A catalytic material comprising the catalyst of claim 1 or claim 20 in combination with a support material.
45. The catalytic material of claim 44, wherein the support material comprises AlPO4, Al2O3, SiO2\u2014Al2O3, CaO, TiO2, ZrO2, MgO, SiO2, ZrO2, HfO2, In2O3, SiC or combinations thereof.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A driving method of a liquid crystal display comprising a back-light module and a liquid crystal display panel, wherein the liquid crystal display panel has a plurality of pixels, the driving method of the liquid crystal display comprising the steps of:
dividing a plurality of grayscale values 0, 1, 2, . . . , N into a plurality of segments, where N is the highest grayscale of the image display system;
detecting a maximum grayscale X of all pixels in the present image;
adjusting output brightness of the back-light module to (YN)\xd7L, where Y is upper limit of one of the segments in which the maximum grayscale X is located, L is a corresponding output brightness of the back-light module to the grayscale N, wherein the corresponding output brightness of the back-light module is retained when the grayscale maximum X is located in either a range between Y and Y+S or a range between Z-S and Z of a present image, where Z is lower limit of one of the segments in which segment the grayscale maximum X is located and S is the predetermined threshold; and
adjusting a grayscale value Xa of each pixel to a mapping grayscale value Xb, and driving each of the pixels with the grayscale value Xb accordingly.
2. The driving method of the liquid crystal display as recited in claim 1, wherein a mapping correlation between the grayscale value Xa and the grayscale value Xb is linear, and the mapping correlation is performed as Xb=(XaY)\xd7N.
3. The driving method of the liquid crystal display as recited in claim 1, wherein the mapping correlation between the grayscale value Xa and the grayscale value Xb is nonlinear.
4. The driving method of the liquid crystal display as recited in claim 1, wherein light transmittance of each of the pixels is adjusted by a bias voltage based on the grayscale value Xb.
5. A driving method of a liquid crystal display comprising a back-light module and a liquid crystal display panel, wherein the liquid crystal display panel has a plurality of pixels, the driving method of the liquid crystal display comprising:
dividing a plurality of grayscale values 0, 1, 2, . . . , N into a plurality of segments, where N is the highest grayscale of the image display system, thereby the brightness of the back-light module is also divided into a plurality of values corresponding to the grayscale segments respectively;
detecting a maximum grayscale X of all pixels in the present image;
adjusting the output brightness of the back-light module to one of the plurality of values for the brightness of the back-light module, wherein the plurality of values are corresponding to the grayscale segments respectively; and
adjusting a grayscale value Xa of each pixel to a mapping grayscale value Xb, and driving each of the pixels with the grayscale value Xb accordingly, wherein a mapping correlation between the grayscale value Xa and the grayscale value Xb is linear, and the nappine correlation is performed as Xb=(XaY)\xd7N, where Y is an upper limit of one of the segments in which the maximum grayscale X is located.