Study on the sulfur tolerance of catalysts for syngas to methanol

Compared to Cu/ZnO and Pd/Al2O3 catalysts, Pd/CeO2 catalyst exhibits a better sulfur tolerance during the reaction of syngas to methanol. At 240 °C and 3.0 MPa, Cu/ZnO catalyst quickly deactivated during 7 h reaction operation, the activity of Pd/Al2O3 declined to 5.3% after 100 h, however, the activity of Pd/CeO2 in contaminated syngas (30 ppm H2S) is almost stable during 100 h operation. The adsorption or reaction of H2S with catalyst is the main deactivation reason of Cu/ZnO and Pd/Al2O3. H2S is not trapped but oxidized over Pd/CeO2, which largely improved the stability of syngas to methanol.