Abstract
This study develops a hydrogen production process from oxidative steam reforming of methanol using hydrogen peroxide as the oxidant (H2O2-OSRM). The liquid phase of H2O2 with methanol will facilitate the design and assembly of fuel cells. In the H2O2-OSRM system test, H2O2 could decompose completely at 150℃. For the catalytic activity of the catalysts in H2O2-OSRM reaction with MeOH:H2O2 volume ratio of 4:1(O2/MeOH =0.089, H2O/MOH=0.514), both CuPd2/Ce10Zn (30 wt% Cu, 2 wt% Pd, 10 wt% Ce and 58wt% Zn) and CuPd2/Ce20Zn (30 wt% Cu, 2 wt% Pd, 20 wt% Ce and 48wt% Zn) catalysts showed ~80% of CMeOH, ~2.4 of YH2, and only 3% of SCO at 250℃. With increasing the addition of Ce, the SCO can be reduced, even to 0%. In MeOH:H2O2 volume ratio of 3:1 (O2/MeOH =0.119, H2O/MOH=0.685), which can provide more oxygen to enhance catalytic activity of catalysts at low temperature. When catalysts were pre-reduced before reaction, it not only improve catalytic activity but also decrease SCO in H2O2-OSRM system .On the whole, compared with H2O2-OSRM and SRM at the same ratio of H2O/MeOH, H2O2-OSRM system can provide more hydrogen than SRM reaction. It approximately provided 1.7 times of hydrogen production at 250℃. The catalytic activity of CuPd2/Ce10Zn and CuPd2/Ce20Zn catalysts through OSRM reaction (O2/MeOH=0.3H2O/MeOH=0.514) showed good performance. CuPd2/Ce10Zn and CuPd2/Ce20Zn catalysts performed ~90% of CMeOH, ~ 2.5 of YH2 at 250℃, and the Sco was kept 0~4% at whole reaction. Since the oxygen content was limited by the concentration of hydrogen peroxide (~50%), the reactivity in H2O2-OSRM system cannot further be enhanced. To more realize the effect of Ce promoter and abatement of CO, O2-TPD, CO-TPR and in-situ DRIFT were investigated to explore the relation between Ce promoter and O2 and CO chemisorption. It obviously shows that more O2 and CO were adsorbed on catalyst with Ce. CuPd2/Ce20Zn catalyst has 10 times intensity of CO chemisorption than CuZn (30 wt% Cu and 70 wt% Zn) catalyst. The presence of CeO2 with oxygen vacancies enhanced the affinity to adsorb oxygen atoms of reactants, as well as even can catalyze CO oxidation at low temperature (90℃).