用密度泛函理论研究H_2PO_2^-在镍催化作用下的氧化过程

Study on Oxidation Process of H_2PO_2^- with Nickel Catalyst Using Density Functional Theory

用密度泛函理论研究化学镀镍过程中还原剂次磷酸盐(如NaH_2PO_2)在气相和镍上的催化作用下的氧化机理.次磷酸盐中的次磷酸根([H2PO2]-)被氧化成亚磷酸根[HP(OH)O2]-,同时镍离子(Ni^(2+))被还原成单质镍并沉积在基底表面.有关还原剂的氧化过程,目前文献中提出了两种可能的反应机理,即"三配位"和"五配位"中间体机理.研究结果表明,镍的催化作用对该反应的进行起关键性的作用,并且"三配位"中间体氧化机理是[H2PO2]-氧化过程的优势反应机理.

The oxidation mechanism of hypophosphite（ [H2PO2]-）, as a Ni-electroless deposition reductant,in gas and with the nickel catalyst was investigated using density functional theory. Hypophosphite is oxidized into phosphite [HP（OH）O2]-and at the same time the nickel ion（ Ni2＋） is reduced into nickel and is deposited on the substrate. Two oxidation mechanisms via 3-coordinate and 5-coordinate intermediates of hypophosphite were proposed in the literature. Our results show that the nickel catalysis plays a key role,and the 3-coordinate intermediate mechanism is predominant in the reaction process for the oxidation of [H2PO2]-.