Understanding FTS selectivity: the crucial role of surface hydrogen.
Monomeric forms of carbon play a central role in the synthesis of long chain hydrocarbons via the Fischer-Tropsch synthesis (FTS). We explored the chemistry of C1Hxadspecies on the close-packed surface of cobalt. Our findings on this simple model catalyst highlight the important role of surface hydrogen and vacant sites for product selectivity. We furthermore find that COadaffects hydrogen in multiple ways. It limits the adsorption capacity for Had, lowers its adsorption energy and inhibits dissociative H2adsorption. We discuss how these findings, extrapolated to pressures and temperatures used in applied FTS, can provide insights into the correlation between partial pressure of reactants and product selectivity. By combining the C1Hxstability differences found in the present work with literature reports of the reactivity of C1Hxspecies measured by steady state isotope transient kinetic analysis, we aim to shed light on the nature of the atomic carbon reservoir found in these studies.
SynCat@DIFFER, Syngaschem BV, PO Box 6336, 5600 HH Eindhoven, The Netherlands. c.j.weststrate@syngaschem.com.
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