助催化剂Co与单晶MoS2边缘面区域及离子溅射解理面相互作用

为了阐明Co原子在钼硫化态催化剂表面上的助催化作用,本文利用UPS,XPS和LEED,研究了Co-Mo催化剂活性相的层状硫化物半导体MoS₂单晶边缘面区域的成分较高的表面以及离子溅射解理面上过渡金属Co的亚原子单层淀积过程。在覆盖度为某个亚原子单层时,表面上存在的与淀积上去的Co有关的界面态,改变了E_F能级的钉扎位置(提高了0.30—0.35eV),使表面势垒下降,表面功函数减小。在E_F附近电子结构的明显变化和LEED研究的结果表明,在MoS₂表面的无序缺陷位置上,可能形成了有利于催化过程的Co-Mo-S类合金键型的活性相。关键词：

THE STUDIES OF THE INTERACTION BETWEEN THE PROMOTOR Co AND THE HIGHLY EDGED SURFACES OR ION SPUTTERED BASAL PLANE OF MoS2 CRYSTAL

To elucidate the promotion action of cobalt on Mo sulfide catalysts, UPS, XPS and LEED have been applied to study the submonolayer deposite process of promotor metal Co on the active catalytic phase for Co-Mo catalyst-the highly edged surfaces and ion sputtered basal plane of MoS₂ crystal. At a certain submonolayer coverage of deposited Co, the new Co-correlated interface states could raise surface E_F to a new higher pinning position by about 0.30-0.35eV. So the surface barrier and work function for these catalytic active phases are decreased. The remarkable changes for electronic structure near E_F and the studies of LEED patterns reveal that the active phase Co-Mo-S, in which the Co-Mo bond appears to behave in much the same way as in the intermetallic bond, could be formed by locating the promotor Co at the surface disorder defects in edge sites.