合成气制低碳醇Cu－Co尖晶石催化剂的在位ESCA研究

IN-SITU ESCA STUDY OF Cu-Co SPINEL CATALYSTS IN OXIDATION STATE FOR SYNTHESIS OF HIGHER ALCOHOL FROM SYNGAS

在位ＥＳＣＡ表征不同状态下Ｃｕ－Ｃｏ尖晶石催化剂表面状态和组成。氧化态催化剂表面富铜，钾表面浓度较低。Ｃｕ为Ｃｕ￣（＋２）；Ｃｏ大部为Ｃｏ￣（＋３），部分为Ｃｏ￣（＋２）。还原态催化剂表面形成富钾层。Ｃｕ为Ｃｕ￣０或Ｃｕ￣（＋１），Ｃｏ为Ｃｏ￣０。Ｃｕ、Ｃｏ间有强相互作用，合成气通过Ｃｕ、Ｃｏ的协同催化作用形成低碳醇。解析反应后脱附的Ｃ＿（１ｓ）峰表明存在三种类型的碳物种：非解离吸附ＣＯ，解离吸附的ＣＯ物种，表面碳酸钾。解离吸附与非解离吸附碳物种的合适比例是形成低碳醇的条件。

In-situ ESCA studies have provided information about the chemical state andsurface composition of spinel catalysts in different states. In the oxidation state copper ag-gregaties on the surface,The valence of Cu is+2and Co mainly is +3 , partially is +2.The binding energies of Cu after reduction is closed to that of Cu￣0 or Cu￣(+1)and Co closed thatof element Co. It was found that K migrates from bulk to surface at reduction state, By ana-lyzing desorption products from the surface after reaction with Mass Spectroscopy,some in-termediates can be monitered. It is thereby suggested that the mechanism for the synthesis ofhigher alcohols from syngas may undergo the following stages:CO dissociation, growth of C-C chain, CO insertion and hydrogenation.