【摘要】 一氧化碳常压气相催化偶联制草酸二乙酯的反应中,由于氢的引入致使偶联反应催化剂Pd-Fe/α-Al2O3失活。研究了不同氢含量条件下催化剂失活以及失活催化剂再生规律,发现催化剂的失活为可逆的,且失活速率随原料气中氢含量的增加而加快。应用X射线光电子能谱、程序升温还原等方法对催化剂中Pd的形态变化进行了分析,发现临氢失活催化剂比反应后催化剂的Pd2+含量要低得多。结果表明,原料气中氢的存在抑制了二价钯的烷氧基中间体Pd(OC2H5)2在催化剂上的产生,从而抑制了草酸二乙酯的生成,导致了催化剂的失活。更多还原

【Abstract】 Pd-Fe/α-Al₂O₃ catalyst was deactivated with introduction of H₂ to gaseous phase reaction of CO coupling to diethyl oxalate（DEO）.Study on effect of different H₂ concentration showed that deactivation of catalyst was reversible and rate of deactivation was correspondent to concentration of H₂.XPS and TPR showed that after CO reaction,Pd on catalyst would be partially oxidized to Pd²⁺,but the amount of Pd²⁺ was much less than that in deactivated catalyst.Due formation of Pd²⁺（OC₂H₅）₂,an intermediate to DEO,was inhibited by H₂,leading to catalyst deactivation.更多还原