TITLE:  Effects of Dispersion and Support on Adsorption, Catalytic and Electronic Properties of Cobalt/Alumina CO Hydrogenation Catalysts: Annual Progress Report, August 1, 1987-July 31, 1988.

AUTHOR:  C. H. Bartholomew.

INST.  AUTHOR:  Brigham Young Univ., Provo, UT. Catalysis Lab.

SPONSOR:  Department of Energy, Washington, DC.

LANGUAGE:  English

PUB.  TYPE:  Technical Report

PUB.  COUNTRY:  United States

SOURCE:  Department of Energy [DE],  22 Aug 88,  5p.

NTIS ORDER NO.: DE89000033/INW  

ABSTRACT: 

 An investigation of the effects of surface structure, dispersion, and support on the adsorption, catalytic, and electronic properties of cobalt/alumina is described, the objectives of which are to determine (1) the effects of surface structure and metal dispersion on the adsorption and catalytic properties of cobalt and (2) the effects of decorating support species on metal crystallites and of direct electronic interactions between metal clusters and support, on the adsorption, catalytic and electronic properties of cobalt supported on alumina. During the first year effects of surface structure and dispersion on the adsorption, activity/selectivity, and electronic properties of Co/W single crystal surfaces and alumina-supported cobalt were investigated in a surface science investigation, lab reactor studies, TPD/TPSR studies, and a Moessbauer spectroscopy study. The structure, stability, surface electronic properties, and chemisorptive properties of vapor-deposited cobalt overlayers (0-4 ML) on W(110) and W(100) were studied by Auger electron spectroscopy, low energy electron diffraction, work function changes, and temperature programmed desorption (TPD) of cobalt, hydrogen, and carbon monoxide. The CO chemisorptive properties of the two cobalt overlayers are quite different, CO adsorption being dissociative on the W(100) surface and nondissociative on the W(110) surface; comparison of the results with those for Ni/W(100) indicate that Co/W(100) as a result of electronic interaction with the tungsten substrate. Activities and selectivities of cobalt/alumina catalysts for CO hydrogenation prepared by decomposition of Co sub 4 (CO) sub 12 were determined as functions of metal loading, dispersion, and extent of reduction. Steady-state activity and product molecular weight were found to increase with increasing metal loading (decreasing dispersion and increasing extent of reduction). 10 refs. (ERA citation 13:057024)

REPORT  NUMBER:  DOE/ET/13763-1

CONTRACT  NUMBER:  FG02-87ER13763