利用表面活性剂辅助模板机理,结合水热法合成出纳米有序的多孔 ZrO_2载体,采用等体积浸渍法制备了 Ni/ZrO_2催化剂;采用固定床微反装置评价了 Ni/ZrO_2催化剂对富氢气体中低含量 CO 选择性甲烷化反应的催化性能;采用 X 射线衍射和程序...利用表面活性剂辅助模板机理,结合水热法合成出纳米有序的多孔 ZrO_2载体,采用等体积浸渍法制备了 Ni/ZrO_2催化剂;采用固定床微反装置评价了 Ni/ZrO_2催化剂对富氢气体中低含量 CO 选择性甲烷化反应的催化性能;采用 X 射线衍射和程序升温还原等方法对载体和催化剂进行了表征。实验结果表明,利用模板剂十六烷基三甲基溴化铵(CTAB)制备的 ZrO_2载体再负载质量分数4%Ni 的 Ni/ZrO_2催化剂具有优异的催化活性,可将 CO 体积分数从1.1%降至0.01%以下,且该催化剂在220～260℃内均能保持较高的活性和选择性。表征结果显示,以 CTAB 为模板剂制备的多孔性纳米 ZrO_2具备优良的载体性能,能促进活性组分 Ni 的分散,载体与活性组分 Ni 之间存在较强的相互作用,提高了催化剂的活性。展开更多
Due to coexisting of H2, CO2 and H2O with CO in hydrogen-rich gas produced from methanol reforming, the selective CO oxidation is companied with the side reactions of H2 oxidation, as well as CO or CO2 methanation and...Due to coexisting of H2, CO2 and H2O with CO in hydrogen-rich gas produced from methanol reforming, the selective CO oxidation is companied with the side reactions of H2 oxidation, as well as CO or CO2 methanation and reverse water-gas shift reaction（RWGS）. This paper investigated the effects of the above side reactions on the selective CO oxidation over a 0.5% Pt/Al2O3 monolithic catalyst. The results showed that after 50% H2 is added into the reactants, the highest CO conversion is only 98.3% at 180℃ when the feed molar ratio of O2 to CO is 1, and the corresponding outlet CO concentration is 180×10 -6 . Adding 50% H2 into the reactants accelerate CO oxidation at low temperatures; the catalyst active reaction temperature window shifts down about 40℃ . CO produced from RWGS is 80×10 -6 at 200℃ indicating that the effect of RWGS on selective CO oxidation becomes obvious at temperatures higher than 200℃. On the other side, CO or CO2 methanation does not take place even at 300℃ under current conditions and has little effects on the selective CO oxidation.展开更多
文摘利用表面活性剂辅助模板机理,结合水热法合成出纳米有序的多孔 ZrO_2载体,采用等体积浸渍法制备了 Ni/ZrO_2催化剂;采用固定床微反装置评价了 Ni/ZrO_2催化剂对富氢气体中低含量 CO 选择性甲烷化反应的催化性能;采用 X 射线衍射和程序升温还原等方法对载体和催化剂进行了表征。实验结果表明,利用模板剂十六烷基三甲基溴化铵(CTAB)制备的 ZrO_2载体再负载质量分数4%Ni 的 Ni/ZrO_2催化剂具有优异的催化活性,可将 CO 体积分数从1.1%降至0.01%以下,且该催化剂在220～260℃内均能保持较高的活性和选择性。表征结果显示,以 CTAB 为模板剂制备的多孔性纳米 ZrO_2具备优良的载体性能,能促进活性组分 Ni 的分散,载体与活性组分 Ni 之间存在较强的相互作用,提高了催化剂的活性。
文摘Due to coexisting of H2, CO2 and H2O with CO in hydrogen-rich gas produced from methanol reforming, the selective CO oxidation is companied with the side reactions of H2 oxidation, as well as CO or CO2 methanation and reverse water-gas shift reaction（RWGS）. This paper investigated the effects of the above side reactions on the selective CO oxidation over a 0.5% Pt/Al2O3 monolithic catalyst. The results showed that after 50% H2 is added into the reactants, the highest CO conversion is only 98.3% at 180℃ when the feed molar ratio of O2 to CO is 1, and the corresponding outlet CO concentration is 180×10 -6 . Adding 50% H2 into the reactants accelerate CO oxidation at low temperatures; the catalyst active reaction temperature window shifts down about 40℃ . CO produced from RWGS is 80×10 -6 at 200℃ indicating that the effect of RWGS on selective CO oxidation becomes obvious at temperatures higher than 200℃. On the other side, CO or CO2 methanation does not take place even at 300℃ under current conditions and has little effects on the selective CO oxidation.
