Steam reforming of 1-methylnaphthalene over pure CeO2 under model coke oven gas conditions containing high H2S concentrations

Abstract Tar and H2S are obstacles to the efficient production of H2 from unused industrial gases and biomass gasification gases. Robust catalysts against tar and H2S are required to produce H2 from such resources. Herein, a stable steam reforming reaction is demonstrated over pure CeO2 under reaction conditions consisting of ~2 vol% 1-methylnaphthalene and ~1000 ppm H2S. The presence of H2S significantly suppressed Ni/MgO/Al2O3 activity and increased carbon deposition, regardless of the steam to carbon (S/C) ratio. In contrast, the promotion or suppression of CeO2 activity in the presence of H2S was dependent on the S/C ratio. At S/C = 1.2, H2S deactivated the CeO2 catalyst and increased carbon deposition. Conversely, H2S promoted the reforming reaction and decreased carbon deposition on CeO2 at S/C ≥ 2.0. The results of this study clarify that pure CeO2 exhibits outstanding and stable activity for the steam reforming reaction of 1-methylnaphthalene in the presence of H2S by controlling the S/C of the inlet gas.