Transition Metal Ions on the Molecular Sieves
D. Blyholder and' D. 0. Bowen, J. Phys. Chem., 66, 1288 (1962). G. D. Blyholder arid 6. W. Cagle, Environ. Sci. Techoi., 5, 158 (1971). G. D. Blyholder, J. Chem. Phys., 36, 2036 (1962). R. W. Sheet; and R. S. Hanson, J. Phys. Chem., 76, 972 (1972). L. D. Neff, 1Ph.D. Dissertation, University of Arkansas, Fayetteville, Arkansas, 1964. M. Hayashi. Y . Shirs, and H. Murata, Bull. Chem. SOC. Jap., 39, 112 (1986). L. H. Jones,J. Chem. Phys., 28, 1215 (1958). D. Smith, J. P Devlin, and D. W. Scott, J, Mol. Spectrosc., 25, 174 (1968). I. F. Trotter and H. VV. Thompson, J. Chem. SOC.,481 (1946). D. W. Scott, J. P. hdcCullough, J. F. Messerly, R . E. Pennington, I. A. Hossenlopp, kl. L. Finke and G. Waddington, J. Amer. Chem. SOC., 80, 55 (1958). I(. Nakamoto, "Infrared Spectra of Inorganic and Coordination Compounds." Wiley New York, N. Y., 1970, p 257. J. P. Fackler and D. Coucouvanis, J. Amer. Chem. Soc., 88, 3913 11965).
(3) G. (4) (5) (6) (7) (8)
(9) (10)
(11) (12) (13) (14)
1653 (15) M. L. Hair, "Infrared Spectroscopy in Surface Chemistry," Marcel Dekker, New York, N. Y., 1967. (16) L. H. Little, "Infrared Spectra of Adsorbed Species," Academic Press, New York, N. Y., 1966, p 404. (17) J. W . May in "Advances in Catalysis," Vol. 21, Academic Press, New York. N. Y., 1970, p 210. (18) G. D. Blyholder. J. Phys. Chem., 68, 2772 (1964). (19) R. Van Hardeveld and F. Hartog in "Advances in Catalysis," Vol. 22. Academic Press, New York, N. Y., 1972, p 75. (20) R . P. Eischens, S. A. Francis, and W. A. Pliskin. J. Phys. Chem., 60, 194 (1956). (21) G. D. Blyholder, private communication. (22) E. Emmett Reid, "Organic Chemistry of Bivalent Sulfur," Voi. I, Chemical Publishing Co., New York, N. Y., 1958, p Ill. (23) M. G. Rudenko and V. N. Gromoua, Doki. Akad. Nauk SSSR, 81, 207 (1951). (24) H. S. Taylor, Refiner Natur. Gasoline Mfr., 9, 83 (1930). (25) H. R. Snyder and G. W. Cannon, J. Amer. Chem. SOC., 66, 1955 (1944). (26) K. Nakamoto, J. Fujita, S. Tamaka, and M. Kobayashi, J. Amer. Chem. SOC.,79, 4904 (1957).
Transition Metal Ions on Molecular Sieves. 11. Catalytic Activities of Transition Metal Ions on Molecular Sieves for the Decomposition of Hydrogen Peroxide lsao Mochida* and Kenjiro Takeshita Research institufe of lndustrial Science, Kyushu Universfty, Fukuoka, Japan 872 (Received December 27, 1973)
The (Catalyticactivities of Y molecular sieves ion exchanged with transition metal ions were observed for the decomposition of hydrogen peroxide, in order to develop a novel catalytic utilization of isolated metal ions (dispersed on the sieve, where the nature of the metal ions can be easily modified by coordination of ligands. Their activities were in order of Pd(I1) < Fe(II1) < Ni(I1) < Ag(1) > Mni(I1) > Co(I1) > Co(II1) > Hg(I1) > Cu(II) > Tl(1) > Cr(m) > Zn(I1). This bell-shaped activity pattern is correlated with the transition metal redox potentials in basic solution. The catalytic activities of Mn(II), Ag(I), and Cu(I1) were improved markedly by coordination with diamine ligands, as observed in homogeneous systems, whereas those of Ni(I1) and Co(I1) were suppressed. Based on studies of the rate dependence on hydrogen ion concentration in addition to the trend of catalytic activities, the decomposition mechanism of hydrogen peroxide is concluded to contain the redox steps for the metal ion, either of which is rate determining, depending on the redox potential of the catalyst.
Introduction Isolated trarhsition metal ions attached to a molecular sieve would be expected to behave as their homogeneous analogs, even though they are located on a solid surface, because they are isolated from one another on the fixed sites of the molecular sieve. Although molecular sievebonded met a1 ions have been extensively studied1 and their catalytic activities have been reported for the oxidation of olefins,2 cycl~hexane,~ and carbon monoxide1 as well as for acid-base reactions,l there is little work in which the metal ion on the sieve is expected to have a chemical nature similar to that of homogeneous catalysts such as metal complexes. We have reported that bidentate ligands such as ethylenediamine formed chelated complexes vvitli an isolated cupric ion on a molecular sieve.4 In the present study, catalytic activities of transition metal ions and their complexes on the sieve were observed for the decomposition of hydrogen peroxide, which has been investigated extensively as a homogeneous reaction
catalyzed by transition metal ions and their complexes as well as by enzymes such as c a t a l a ~ e It . ~ may be of value to try to develop a novel catalytic utilization of the isolated metal ions dispersed on the sieve, taking advantage of the possibility that the nature of such 11 catalyst may be easily modified by ligands as in the case of homogeneous transition metal systemsS6The present. study is one of such trials.
Experimental Section Chemicals. Hydrogen peroxide (30% aqueous solution) was obtained from Wako Pure Chemical Industry. Ligands obtained from Tokyo Kasei Co. were used without purification. Catalysts. The ion-exchanged molecular sieves examined are listed in Table I. They were prepared by ion exchange of Y molecular sieves (Linde), Na(1)-Y, with aqueous solutions of metal sulfates or nitrates. except for Cu(II), Pd(II), and Co(II1) ions. Ammine complexes of the first two and ethylenediamine complexes of the latter The Journal of Physical Chemistry, Voi. 78. N o . 76, 1974
lsao Mochida and Kenjiro Takeshita
1654
TABLE I: Catalytic Activities of Metal Ions and Their Ethylenediamine Chelates on Y Sieve for the Decomposition of H I O ~
ActiVitya
1 2 3 4 5 6 7 8 9 10 11 12 13
4 . 8 ;< l o 3 6 . 8 X lo2 2.8 X lo2 1.4 :< 102 1 . 9 ;< 10 7.0 6.8 4 . 9 :< Po-' 3.8 4 . 9 :< 10-1 3 . 7 x 10-1 3 . 3 x 10-1 1 . 4 :< 10-1
Activity of ethylenediamine chelate"
AGI,~
AG*,
