Study of Catalysts for Hydrogen Production by the High Temperature Steam Reforming of Methanol

Abstract

Abstract In the present study, a series of Ir‐based catalysts, supported on Al 2 O 3 , ZrO 2 , CeO 2 , and Ce x Zr 1‐x O 2 , are investigated for the production of hydrogen by the high temperature steam reforming of methanol (SRM). Results show that CeO 2 and Ce x Zr 1‐x O 2 can promote the CO water gas shift (WGS) reaction, which is involved in the SRM network. Ir/CeO 2 exhibits a better initial methanol conversion and its stability can be enhanced by the addition of ZrO 2 to CeO 2 . The TPR and XRD characterization of the CeO 2 ‐ZrO 2 mixed oxides shows that Ce 0.5 Zr 0.5 O 2 is the optimum support in maintaining catalyst activity, as well as stability. The addition of the precious metal Pt to Ir/Ce 0.5 Zr 0.5 O 2 demonstrates a synergistic effect and can obviously increase the selectivity of H 2 . In the meantime, the CO content in the reformate products decreases from 9 mol‐% to 6 mol‐%. Under the conditions of H 2 O / CH 3 OH=1.5 (molar ratio), LHSV=2.5 h –1 , and a reaction temperature of 400 °C, a 92% methanol conversion is obtained during a 200 hour test on a 0.3%Ir‐0.3%Pt/Ce 0.5 Zr 0.5 O 2 catalyst and the stability is better than that of a commercial copper‐based catalyst.