Physicochemical properties of MnO/sub 2/ and MnO/sub 2/-CuO and their relationship with the catalytic activity for H/sub 2/O/sub 2/ decomposition and CO oxidation

Journal Article · Sun Jul 01 00:00:00 EDT 1979 · J. Catal.; (United States)

OSTI ID:6015917

Kanungo, S B

The catalytic activity of MnO/sub 2/ prepared by different methods has been determined from the initial rate of decomposition of H/sub 2/O/sub 2/ and the conversion of CO to CO/sub 2/. The activity is correlated with various physicochemical properties such as active oxygen, surface excess oxygen, surface OH groups, crystalline modifications, lattice parameters, and thermal decomposition data. Some of the above properties are interrelated. Experimental evidence shows that the presence of Mn/sup 3 +/ as MnOOH in the MnO/sub 2/ lattice is mainly responsible for the origin of catalytic activity in nonstoichiometric manganese dioxide where electron transfer between Mn/sup 4 +/ and Mn/sup 3 +/ ions can take place. The loss of strongly bound compositional water creates lattice defects which are also responsible for the increase in the catalytic activity. The reason for the promoting effect of CuO in MnO/sub 2/-CuO catalysts has been discussed in the light of the formation of surface CuMn/sub 2/O/sub 4/ through the exchange of Cu/sup 2 +/ on the hydrated manganese oxide surface. 10 figures, 3 tables.

• Research Organization: Regional Research Lab., Orissa, India
• OSTI ID: 6015917
• Journal Information: J. Catal.; (United States), Vol. 58:3
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CARBON MONOXIDE
OXIDATION
COPPER OXIDES
CATALYTIC EFFECTS
CHEMICAL PROPERTIES
PHYSICAL PROPERTIES
HYDROGEN PEROXIDE
DECOMPOSITION
MANGANESE OXIDES
CARBON DIOXIDE
COPPER
ELECTRON TRANSFER
HYDROXYL RADICALS
OXYGEN
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
COPPER COMPOUNDS
CRYOGENIC FLUIDS
ELEMENTS
FLUIDS
HYDROGEN COMPOUNDS
MANGANESE COMPOUNDS
METALS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PEROXIDES
RADICALS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
400201* - Chemical & Physicochemical Properties