Growing concerns about the environmental impact of sulfur emissions from stationary sources, as well as recent regulatory initiatives, have prompted investigations for advanced sulfur reduction strategies. Herein, we present a novel process/catalyst combination for reducing tailgas SOx and H2S emissions to very low levels (1-5 ppmw). The Mobil Oil SOx Treatment Process (MOST) consists of the following steps: (1) combustion of tailgas sulfur species to convert all sulfur species to SO2/SO3; (2) adsorption of SOx onto a high-capacity sorbent; and (3) in a separate step, reductive desorption of the sulfur as a concentrated stream of mainly SO2 and H2S. The MOST Process utilizes a regenerable promoted spinel-based sorbent with very high SOx uptake capacities (>50 wt%), and is both, robust and operationally simple. Catalyst selection, process scoping studies, and characterization to help understand the nature of the oxidative sorption and reductive regeneration steps, as well as the state of the sorbent during these steps, are described. (C)2000 Elsevier Science B.V. All rights reserved.