PART I: CONDUCTIVITY OF THORIA POWDER IN CARBON DIOXIDE ATMOSPHERES. PART II: A PLATINUM CATALYST FOR THE COMBINATION OF HYDROGEN AND OXYGEN IN THORIA SLURRIES

Journal Article · Tue May 01 04:00:00 EDT 1962 · Dissertation Abstr.

OSTI ID:4813088

Horton, R M

Carbon dioxide was adsorbed on pellets pressed from thoria powder (22.8 m/sup 2//gm) and the conductivity isotherms determined at temperatures between 250 and 550 deg C in a d-c electric field. The conductivity isotherms are explained by two parallel resistances, one consisting of bulk conduction controlled by the particle-to-particle contacts and the other resistance being explained by two alternate mechanisms: ionic conduction along the surface of the pores or thermionic emission across the pores. A theoretical interpretation of the results is given. A platinum catalyst was prepared by refluxing together an aqueous suspension of platinic acid and thorium hydroxide. A small amount of this catalyst was added to a thoria slurry in an autoclave. After the slurry was heated and while it was being agitated, oxygen and hydrogen were added to the autoclave and their rate of combination followed by recording the pressure as a function of time. The reactions were usually first order with respect to pressure. Results indicated that the catalyst was adsorbed on the previously inert thoria, causing an increase in the rate. The activation energy for the process was 4.0 kcal/mole. The kinetics were found to be first order with respect to oxygen. These facts suggested that the slow step in the reaction was the diffusion of oxygen to the cata1yst. The catalyst was found to maintain its activity even after 200 tests upon the same charge.

• Research Organization: Univ. of Utah, Salt Lake City
• NSA Number: NSA-16-022609
• OSTI ID: 4813088
• Journal Information: Dissertation Abstr., Journal Name: Dissertation Abstr. Vol. Vol: 22
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ACTIVATION ENERGY
ADSORPTION
CARBON DIOXIDE
CATALYSIS
CHEMICAL REACTIONS
CONTROL
CURRENTS
DIFFUSION
ELECTRIC CONDUCTIVITY
ELECTRIC FIELDS
HEATING
HYDROGEN
IONS
METALS, CERAMICS, AND OTHER MATERIALS
OXYGEN
PELLETS
PLATINUM
POROSITY
POWDERS
PREPARATION
PRESSURE
PRESSURE VESSELS
REACTION KINETICS
SLURRIES
SURFACES
SUSPENSIONS
TEMPERATURE
TESTING
THERMODYNAMICS
THORIUM HYDROXIDES
THORIUM OXIDES
WATER