摘要
用程序升温还原（ＴＰＲ）、ＸＰＳ、磁化率测量等技术并结合ＣＯ加氢反应，对共沉淀方法制备的Ｎｉ—Ｃｕ／ＺｎＯ催化剂中组分间的相互作用进行了研究．结果表明，载体ＺｎＯ对ＣｕＯ具有分散作用，而与ＮｉＯ具有强相互作用．催化剂还原后Ｎｉ与Ｃｕ形成了Ｎｉ－Ｃｕ合金，而且Ｃｕ在一定程度上在合金表面富集．Ｎｉ与Ｃｕ间可能存在电子效应，即Ｃｕ向Ｎｉ供电子．在Ｎｉ－Ｃｉ／ＺｎＯ催化剂中，存在Ｎｉ－Ｃｕ金属间相互作用以及Ｚｉ－ＺｎＯ、Ｃｕ－ＺｎＯ金属－载体相互作用。金属间的相互作用能减弱（或破坏）金属与载体间的相互作用．
A series of Ni-Cu/ZnO catalysts were prepared by co -precipitation, characteed byternp erature - programmed reduction (TPR), magnetic susceptibility, X -ray photoelectronspectroscopy (XPS) techniques and studied in CO hydrogenation. TPR results revealed that thesupport, ZnO, disperses CuO, but strongly interactes with NiO. After reduction, Ni-Cu alloywas formed. Magnetic susceptibility and XPS results further indicated that Cu enriches on thealloy and there might be an electronic effect between Ni and Cu, i.e. Cu Aught donate electronsto Ni. In CO hydrogenation, all the catalysts seldrively catalyzed the formation of methanol.With the increase of Ni/Cu ratios, the selectivity to methanol decreases, while that to methaneincreases. None of the bimetallic catalysts showed the activity of a sample of combination ofNi/ZnO and Cu/ZnO with corresponding composition. The total reaction rates did not increaseappredably with increasing Cu concentration at constant Ni content, but decreased drasticallyWhen Ni was added at constant Cu content. The results of this study shows that there are bothinteractions between Ni and Cu metals and interactions between metals and support. Theinteraction between metals can weaken the interactions between metals and support.
关键词
双金属催化剂
镍
铜
相互作用
加氢
催化剂
Bimetallic catalyst Metal-support interaction Metal-mwtal interaction AlloyCO hydrogenation
