The Intelligent Catalyst: Pd-Perovskite Having the Self-Regenerative Function in a Wide Temperature Range

Abstract:

An innovative Pd-perovskite “Intelligent Catalyst”, which exhibits a greatly improved durability owing to the self-regeneration function of Pd nanoparticles, has been developed. The Pd-perovskite catalyst was prepared by the alkoxide method, and X-ray absorption fine structure (XAFS) measurements were carried out in SPring-8 using the 8-GeV synchrotron radiation. Pd occupied the B-site (6-fold coordination) of the perovskite lattice in the oxidative atmosphere, and segregated out to form metallic nanoparticles in the reductive atmosphere. The catalyst retained a predominantly perovskite structure throughout a redox cycle of the exhaust-gas, while the local structure around Pd could be changed in a completely reversible manner. The agglomeration and growth of the metal particles is suppressed as a result of the Pd movement between inside and outside the perovskite lattice. This function enables an automotive catalyst to regenerate itself into an active state in fluctuation typically encountered in the exhaust gas from the gasoline engine. And it is revealed, by in-situ and ex-situ XAFS analyses, that the self-regenerative function of Pd occurred in a wide temperature range from very low to high one. The intelligent catalyst is one solution for precious metals supply and demand problem, and is expected to become the global standard of the catalyst technology.

• Periodical: Key Engineering Materials (Volumes 317-318)
• Pages: 827-832
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.317-318.827
• Online since: August 2006
• Authors: Hirohisa Tanaka, Isao Tan, Mari Uenishi, Masashi Taniguchi, Y. Nishihata, Jun'ichiro Mizuki
• Keywords: Automotive Emission, Catalyst, Nanoparticle, Palladium, Perovskite, Self-Regeneration

References

[1] http: /snet. sntt. or. jp/imf/: The intelligent materials forum 1990 , The society of non-traditional technology.

[2] The data are quoted and illustrated graphically, from Platinum Interim Review, Johnson Matthey.

[3] Y. Nishihata, J. Mizuki, T. Akao, H. Tanaka, M. Uenishi, M. Kimura, T. Okamoto and N. Hamada, Nature, 418 (2002) 164.

DOI: 10.1038/nature00893

[4] H. Tanaka, M. Uenishi, I. Tan, M. Kimura, Y. Nishihata and J. Mizuki, SAE Paper, 2001-1-1301 (Society of Automotive Engineers, Warrendale, Pennsylvania, 2001).

DOI: 10.4271/2001-01-1301

[5] H. Tanaka, M. Uenishi, I. Tan, M. Kimura and K. Dohmae, Topics in Catalysis, Vol. 16/17, No. 1-4 (2001) 63.

DOI: 10.1023/a:1016626713430

[6] H. Tanaka, Kankyo Shokubai handbook, (ed. ) M. Iwamoto, (NTS, Tokyo, 2001) 320.

[7] M. Uenishi, I. Tan and H. Tanaka, J-SAE, Vol. 55, No. 9 (2001) 81.

[8] D.B. Meadowcroft, Nature, 226 (1970) 847.

[9] Parravano, J. Chem. Phys., 20, (1952) 342.

[10] W.F. Libby, Science, 171 (1971) 499.

[11] R.J.H. Voorhoeve, J.P. Remeika, L.E. Trimble, A.S. Cooper, F.J. Disalvo and P.K. Gallagher, J. Solid State Chem., 14 (1975) 395.

[12] T. Kudo, T. Gejo and K. Yoshida, Environ. Sci. Tech., 12 (1978) 185.

[13] H. Fujii, N. Mizuno and M. Misono, Chem. Lett., (1987) 2147.

[14] T. Nitadori, T. Ichiki and M. Misono, Bull. Chem. Soc. Jpn., 61 (1988) 621.

[15] K. Tabata and S. Kohiki, J. Mater. Sci., 23 (1988) 1056.

[16] R.M. Hazen, Sci. Am., 6 (1988) 52.

[17] L.G. Tejuca, J.L.G. Fierro and J.M.D. Tascon, Adv. Catal., 36 (1989) 237.

[18] H. Tanaka and M. Misono, Current Opinion in Solid State and Mater. Sci, 5 (2001) 381.

[19] H. Tanaka, H. Fujikawa and I. Takahashi, SAE Paper, 930251 (1993).

[20] H. Tanaka, I. Takahashi, M. Kimura and H. Sobukawa, (Eds. ) Y. Izumi, H. Arai and M. Iwamoto, Science and Technology in Catalysts 1994, (Kodansya-Elsevier, Tokyo, 1995) 457.

[21] H. Tanaka, H. Fujikawa and I. Takahashi, SAE Paper, 950256 (1995).

[22] H. Tanaka, N. Mizuno and M. Misono, Appl. Catal. A: General, No. 244 (2003) p.371.

[23] I. Tan, H. Tanaka, M. Uenishi, N. Kajita, M. Taniguchi, Y. Nishihata and J. Mizuki, SAE Paper, 2003-01-0812 (2003).

DOI: 10.4271/2003-01-0812

[24] N. Sato. H. Tanaka, I. Tan, M. Uenishi, N. Kajita, M. Taniguchi, K. Narita and M. Kimura, SAE Paper, 2003-01-0813 (2003).

DOI: 10.4271/2003-01-0813

[25] H. Tanaka, M. Taniguchi, N. Kajita, M. Uenishi, I. Tan, N. Sato, K. Narita and M. Kimura, Topics in Catalysis, Vol. 30/31 (2004) 389.

DOI: 10.1023/b:toca.0000029780.70319.36

[26] Y. Nishihata, J. Mizuki, H. Tanaka, M. Uenishi and M. Kimura, J. Phys. Chem. Solids (in press).

[27] M. Uenishi, M. Taniguchi, H. Tanaka, M. Kimura, Y. Nishihata, J. Mizuki and T. Kobayashi, Appl. Catal. B: Environ. (submitted).

[28] H. Tanaka, I. Tan, M. Uenishi, M. Taniguchi, M. Kimura, Y. Nishihata and J. Mizuki, J. Alloy & Compounds (submitted).