Statistical modelling of adsorption processes on catalyst surfaces: preliminary report. [Heterogeneous catalysis]

Technical Report · Wed Dec 01 04:00:00 EST 1976

OSTI ID:7319609

Fuller, Jr, E L; Ebey, S; Uppuluri, V R.R.

A three-faceted approach was fruitful in modelling surface reactions involved in heterogeneous catalysis. The chemisorption reactions have been modelled as immobile binding, involving adjacent sites on the solid surfaces, forming the ''activated intermediate'' which is the key step in most intrafacial or suprafacial catalytic processes. The kinetics and stoichiometry of these processes was analyzed by a detailed comparison of experimental data, computer simulation, and mathematical analyses. Several unexplained experimental results are satisfactorily interpreted in terms of these models on a semi-quantitative basis. Previously, qualitative explanations had been proposed which embodied much of the logic of our models. The results are adequately developed to determine, by inference, the lattice structure of the surfaces in terms of the kinetics and stoichiometry of the adsorption processes. The results of this preliminary study indicate that additional analyses will be beneficial in interpreting surface reactions of interest in the field of heterogeneous catalysis. The results have been very successful in giving a phenomenological model where the restructuring process involves suprafacial desorption-readsorption to achieve the complete ideal monolayer. Data show that this process depends on the nature of the adjacent fluid phase. The process is virtually impossible for gas phase contact whereas it is slow and first order through the more structured liquid phase.

• Research Organization: Oak Ridge National Lab., Tenn. (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 7319609
• Report Number(s): ORNL-5231
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ADSORPTION
CATALYSIS
CATALYSTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISORPTION
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DESORPTION
KINETICS
MATHEMATICAL MODELS
REACTION KINETICS
SEPARATION PROCESSES
SIMULATION
SORPTION
SORPTIVE PROPERTIES
SURFACE PROPERTIES
SURFACES