【摘要】 用XPS考察了低碳混合醇合成用CuO-ZnO-Al₂O₃-K₂CO₃催化剂在反应条件下的表面状态及助剂K的作用。结果表明,在还原及反应后,表面没有稳定的Cu⁺和Cu²⁺存在,仅能检测到Cu⁰物种,Cu⁰是催化剂的活性组分之一。在表面存在着混合醇合成活性单元（□为氧空位）和甲醇合成活性单元,助剂K被稳定地联结在Al₂O₃上。当Al₂O₃不存在时,K会大量富集在催化剂表面。未还原催化剂中,K与CuO之间存在着强的电子相互作用,K作为施主把电子传递给CuO。但在反应条件下,未检测到K与Cu⁰之间明显的电子相互作用。K的存在可适当提高高级醇的选择性。更多还原

【Abstract】 The surface states of CuO-ZnO-Al2O3-K2CO3 catalysts for mixed alcohol synthesis and the role of modifier potassium v ere studied by XPS measurement under simulated reaction conditions. After reduction and reaction, no stable Cu+ and Cu2+ ions were found, only Cu0 v as detected. Cu0 is believed to be dispersed in oxygen-deficient species ZnOx(x≤1 )and A12O3 in the form of microcr -stallites. It is proposed that Cu?is one of the active components on the surface,the active units exist as Cu- Zn-O-K("□" is oxygen vacancy) for mixed alcoholas well as Cu - Zn-O for CH3OH synthesis.The potassium was bonded to Al2O3. In the absence of Al2O3, surface enrichment in K was observed. There exists strong elecironic interaction between K and reduced CuO with K acting as a donor and transferring electrons to CuO. But no obvious electronic interaction between K and Cu0 v, as detected during reaction. It is suggested that besides the possible action of neutralizing the acidit of Al2O3, K can act on Cu through ZnO to stabilize ox gen-containing intermediates, promoting C-C chain grov, th and improving higher alcohol selectivity .更多还原