【摘要】 以ZrO2,La2O3或MgO为助剂制备了氧化铝担载型铱基催化剂,考察了其对甲醇裂解反应的催化性能,并用X射线光电子能谱、程序升温还原、H2程序升温脱附和CO程序升温脱附等技术对催化剂进行了表征.结果表明,ZrO2,La2O3和MgO助剂的引入均能提高主产物氢气和CO的选择性.ZrO2是甲醇裂解反应的优良助剂,可以显著提高甲醇的转化率和氢气的收率.氧化铝担载型贵金属铱基催化剂上存在强的氢溢流现象,这使催化剂具有良好的反应性能,同时有利于产物的脱附,氧化物助剂的加入能够进一步促进氢的溢流.更多还原

【Abstract】 The alumina-supported noble metal iridium catalysts were prepared by the impregnation method.The effect of additive ZrO₂,La₂O₃,or MgO on the catalytic performance was investigated.The supported catalysts were used for the methanol decomposition reaction and were characterized by（X-ray） photoelectron spectroscopy,temperature-programmed reduction（TPR）,temperature-programmed desorption of hydrogen（H₂-TPD）,and temperature-programmed desorption of carbon monoxide.The promoter addition could remarkably improve the hydrogen selectivity and CO selectivity of Ir/Al₂O₃ catalyst in the methanol decomposition.La₂O₃ and ZrO₂ were also good promoters for enhancing the methanol conversion.Both hydrogen and CO were held strongly by the MgO-modified Ir/Al₂O₃ catalyst,which was not favorable for the methanol conversion.The results of TPR and H₂-TPD showed that hydrogen spillover existed in the alumina-supported iridium catalyst.The addition of one of the three promoters could significantly enhance the hydrogen spillover effect.更多还原