Sulfur as a catalyst promoter or selectivity modifier in heterogeneous catalysis

Abstract

For most heterogeneous catalysts adsorbed sulfur and sulphur-containing molecules are generally regarded as a poison. However, a growing number of reports from academia and industry demonstrate that sulfur may act as an activity promoter or selectivity modifier in heterogeneous catalysis. Reports from a variety of areas such as Fischer–Tropsch synthesis, catalytic reforming, regio and chemoselective hydrogenation as well as CO oxidation, hydrocarbon oxidation and NO_x reduction are discussed. Based on the literature cited, comments on the levels of sulfur necessary to observe a promotional effect are suggested/proposed, as well as some of the techniques which can be applied to understand such effects.