Kinetics of biomolecular reactions on platinum

Thesis/Dissertation · Mon Jan 01 04:00:00 EST 1979

OSTI ID:6356614

Blieszner, J W

The rate of the water gas shift reaction on polycrystalline platinum at 0.12-6.5 mm Hg total pressures and 500/sup 0/-1500/sup 0/K catalyst temperature in a Pyrex flow reactor with excess carbon monoxide or water vapor displayed both first-order and negative first-order carbon monoxide pressure dependence and half-order water vapor pressure dependence. The reaction is one of few with shifting order in a bimolecular reaction with competitive adsorption. Constant parameter one-state (Langmuir-Hinshelwood) kinetics were used to fit the experimental data. The rate of hydrogen oxidation on the platinum catalyst at 0.03-1.0 mm Hg total pressure and 400/sup 0/-1700/sup 0/K was first order in oxygen at low pressures and independent of hydrogen pressure at low temperature. At high temperature, the rate became limited by the flux of oxygen to the surface before the expected positive hydrogen pressure dependence was observed. An extension of fixed parameter Langmuir-Hinshelwood kinetics was developed to include coverage-dependent heats of adsorption from surface heterogeneities or lateral interactions between absorbate molecules, and a coverage-dependent activation energy of reaction.

• OSTI ID: 6356614
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400301 -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
CATALYTIC EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DATA
ELEMENTS
EQUATIONS
EXPERIMENTAL DATA
HIGH TEMPERATURE
HYDROGEN
INFORMATION
KINETIC EQUATIONS
KINETICS
LOW PRESSURE
MEDIUM VACUUM
METALS
NONMETALS
NUMERICAL DATA
OXIDATION
PLATINUM
PLATINUM METALS
PRESSURE DEPENDENCE
REACTION KINETICS
SHIFT PROCESSES
TRANSITION ELEMENTS
VERY HIGH TEMPERATURE
WATER GAS PROCESSES