Interactions of SO2 and H2S with amorphous carbon films

There is significant interest in development of efficient catalyst-sorbents for the capture and conversion of sulfur-compounds such as H2S and SO2. In this work, ultra-high vacuum (UHV) techniques have been used to carefully prepare and thoroughly characterize amorphous carbon (a-C) thin films as models of activated carbon sorbents. Films with modified surface chemistries were prepared by oxidation of a sputter deposited carbon film (a-COx) and by sputter depositing carbon in the presence of N2 (a-CNx) or methane (a-CHx). Temperature programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS) were used to study H2S and SO2 surface chemistry on these films and on a highly oriented pyrolytic graphite (HOPG) reference-surface. The modification of the carbons with different heteroatoms influences both the strength of their interactions with SO2 and H2S and their capacities for sulfurcompound adsorption. 2009 Elsevier B.V. All rights reserved.