负载型金属催化剂上甲醇液相重整制氢研究

研究了Pt,Ru,Ni为活性金属的负载型催化剂上甲醇质量分数为5%的水溶液的液相重整反应。在合适的温度、体积空速下，Pt基催化剂表现出较好的反应性能，甲醇转化率可达99%，H2选择性达98%以上，产物中CO体积分数小于0.01%。Ni/Al2O3催化剂可使甲醇转化率最高达到98%以上，H2选择性随转化率升高而下降，但不低于80%。Ru/Al2O3催化剂上甲醇的转化率最高，可达到98%以上，但其H2选择性随着转化率的升高，从68%快速下降至20%，明显与Pt、Ni基催化剂上的反应机理不同。根据反应条件和产物组成变化，进一步探讨甲醇反应路径，当产物中H2与CH4选择性比值高于2/3时，反应路径以重整制氢为主；当比值低于2/3时，反应路径以甲烷化为主。

AQUEOUS-PHASE REFORMING OF METHANOL FOR HYDROGEN PRODUCTION OVER SUPPORTED METAL CATALYST

Aqueous-phase reforming (APR) of the water solution with methanol mass fraction of 5 % over catalysts with Pt, Ru, Ni as active metals was studied. Pt-based catalysts exhibited good reaction performance at suitable temperature and LHSV. The conversion rate of methanol reached 99%, the selectivity of hydrogen was over 98%, and CO volume fraction in the product was below 0.01%. The conversion rate of methanol over Ni/Al2O3 was > 98%, however, the hydrogen selectivity decreased with the increase of the conversion rate but it was still above 80%. The methanol conversion rate on Ru/Al2O3 was over 98%, but the hydrogen selectivity decreased rapidly from 68% to 20% with the increase of methanol conversion rate. The reaction mechanism was obviously different from that of Pt and Ni. According to the reaction conditions and the product composition, the reaction path of methanol APR was further discussed. When the ratio of H2 to methane (CH4) in the product was higher than 2/3, the main reaction path was mainly hydrogen production. When the ratio was lower than 2/3, the reaction path was dominated by methanation.