C2H2,C2H4与K在Ru(1010)表面上共吸附的UPS研究

摘要

The ethylene (C2H4)and acetylene (C2H2)co-adsorbed with K on Ru(1010)surface has been studied by using ultraviolet spectroscopy(UPS).The results show that ethylene (C2H4) is absorbed in molecular state on Ru(1010)surface stably below 200K.The dehydrogenated of ethylene occurs at 200K.The main product of the dehydrogenation of the absorbed ethylene (C2H4)is the acetylene (C2H2).After the dehydrogenation of the absorbed ethylene(C2H4),the binding energies of σCC and σCH bonds have an increase of 0.2eV and 0.5eV respectively.The acetylene is absorbed in molecular state on Ru(1010)surface stably at room temperature.On a K pre-covered surface,the σCC peak disappears at room temperature.The element K promotes the dissociation of acetylene on Ru(1010)surface.%利用紫外光电子谱(UPS)对乙烯(C2H4)和乙炔(C2H2)气体在Ru(1010)表面的吸附及与K的共吸附进行了研究，实验结果表明：当衬底温度超过200!K，乙烯即发生脱氢反应后，σCH和σCC能级均向高结合能方向移动.在室温下，σCH和σCC能级位置与乙炔在Ru(1010)表面的吸附时的分子能级完全一致.乙烯发生脱氢反应后的主要产物为乙炔.衬底温度从120!K升到室温，Ru(1010)表面上乙炔的σCH和σCC能级均未发现变化.室温下乙炔仍然可以在Ru(1010)表面以分子状态稳定吸附.在有K的Ru(1010)表面上，室温时σCC谱峰几乎消失.碱金属K的存在促进了乙炔的分解.