Direct reforming catalyst for molten carbonate fuel cells, method for preparing the same and method for improving long-term stability thereof by wettability control on molten carbonate electrolyte

Patent metadata

Field	Value
Publication number	US-2016006040-A1
Application number	US-201514791656-A
Country	US
Kind code	A1
Filing date	Jul 6, 2015
Priority date	Jul 7, 2014
Publication date	Jan 7, 2016
Grant date	—

Abstract

Disclosed is a homogeneous catalyst having a single phase of Perovskite oxide, wherein at least one doping element is substituted at site A, site B or sites A and B in ABO 3 Perovskite type oxide so that the wettability with a liquid molten carbonate electrolyte may be decreased. The catalyst may have high catalytic activity, inhibit catalyst poisoning caused by creepage and evaporation of a liquid molten carbonate electrolyte, maintain high reaction activity for a long time, provide high methane conversion, and allow production of synthetic gas having a high proportion of hydrogen.

First claim

What is claimed is:

1 . A direct reforming catalyst for molten carbonate fuel cells being a homogeneous catalyst having a single phase of Perovskite oxide, wherein at least one doping element is substituted at site A, site B or sites A and B in ABO 3 Perovskite type oxide, and
the substitution with the doping element decreases wettability with a liquid molten carbonate electrolyte as compared to wettability with a liquid molten carbonate electrolyte in non-substituted ABO 3 Perovskite type oxide.

2 . The direct reforming catalyst for molten carbonate fuel cells according to claim 1 , which is a single-phase of Perovskite oxide represented by the following Chemical Formula 1:
A 1-x C x B 1-y D y O 3   [Chemical Formula 1]
wherein x is equal to or larger than 0 and smaller than 1, and y is equal to or larger than 0 and smaller than 1, with the proviso that x and y do not represent 0 at the same time; A and B are elements different from each other and form site A and site B, respectively, in ABO 3 Perovskite type oxide, wherein A is an element having a valence of +2 and B is an element having a valence of +4; C and D are doping elements different from each other and have reforming characteristics to hydrocarbon fuel; and the A 1-x C x B 1-y D y O 3 type Perovskite oxide has lower wettability with a liquid molten carbonate electrolyte as compared to the ABO 3 type Perovskite oxide.

3 . The direct reforming catalyst for molten carbonate fuel cells according to claim 2 , wherein a wetting angle (θ) of the A 1-x C x B 1-y D y O 3 type Perovskite oxide with a liquid molten carbonate electrolyte is larger than 20° under reductive atmosphere.

4 . The direct reforming catalyst for molten carbonate fuel cells according to claim 3 , wherein the wetting angle (θ) is larger than 50°.

5 . The direct reforming catalyst for molten carbonate fuel cells according to claim 4 , wherein the wetting angle (θ) is larger than 90°.

6 . The direct reforming catalyst for molten carbonate fuel cells according to claim 2 , wherein each of C and D in Chemical Formula 1 is any one selected from the group consisting of Ru, Rd, Au, Ag, Pd, Cu, Ni and Pt.

7 . The direct reforming catalyst for molten carbonate fuel cells according to claim 2 , wherein y=0 and 0<x≦0.5, x=0 and 0<y≦0.5, or 0<x≦0.5 and 0<y≦0.5.

8 . The direct reforming catalyst for molten carbonate fuel cells according to claim 2 , wherein the catalyst represented by Chemical Formula 1 is one represented by the following Chemical Formula 2:
SrTi 1-y Ru y O 3   [Chemical Formula 2]
wherein y is larger than 0 and smaller than 1.

9 . The direct reforming catalyst for molten carbonate fuel cells according to claim 8 , wherein y is larger than 0 and equal to or less than 0.3.

10 . The direct reforming catalyst for molten carbonate fuel cells according to claim 1 , which is pellet-type.

11 . The direct reforming catalyst for molten carbonate fuel cells according to claim 1 , wherein the liquid molten carbonate electrolyte is a Li/K-based, Li/Na-based or Li/K/Na-based liquid molten carbonate electrolyte.

12 . A molten carbonate fuel cell comprising the direct reforming catalyst for molten carbonate fuel cells as defined in claim 1 .

Assignees

• Korea Inst Sci & Tech

Inventors

• Yoon Sung Pil
• Kim Hyoung-Juhn
• Yoon Chang Won
• Jang Seong Cheol
• Choi Sun-Hee
• Han Jonghee
• Ham Hyung Chul

Classifications

• H01M8/145

  comprising carbonates · CPC title

• H01M2008/147

  Fuel cells with molten carbonates · CPC title

• H01M4/9033 Primary

  Complex oxides, optionally doped, of the type M1MeO3, M1 being an alkaline earth metal or a rare earth, Me being a metal, e.g. perovskites · CPC title

• H01M8/14

  Fuel cells with fused electrolytes · CPC title

• H01M4/90 Primary

  Selection of catalytic material · CPC title