摘要
Ce(SO_4)_2和V_2O_作为氧化性的助催化剂在硝基苯还原羰基地为苯氨基甲酸酯反应中能显著提高PdCl_2-邻菲咯啉(phen)体系的催化活性,应用LR,UV,循环伏安法和XPS测试结果表明Ce(SO_4)_2与Ptren容易生成配合物,Ce(Ⅳ)的作用在于维持Pd(Ⅱ)的氧化态,而Ce(Ⅲ)可能有助于硝基苯的脱氧。
The catalytic effectiveness of Pd( Ⅱ )-phen catalyst system in the reductive car-bonylation of nitrobenzene to phenylurethane can be significantly improved by using Ce(SO4)2 and V2O5 as promoters. The role and the chemical state of Ce(SO4)2 under the reaction conditions were investigated.The results obtained by using cyclic-vollammetry , IR and XPS show that there existed certain mode of coordination among Ce(SO4)2 and phen under reaction Condition, it is reasonable to suppose that a redox cycle involving Ce( Ⅲ /Ⅳ ) cations might occur in the catalytic system:At the high oxidation state Ce( Ⅳ ) may inhibit the reduction of Pd( Ⅱ ) by reoxidation of Pd(0) to Pd( Ⅱ ), while at the low oxidation slate Ce( Ⅲ ) would assist the deoxygenation of nitrobenzene with cocomitant reoxidation of Ce( Ⅲ) to Ce( Ⅳ ).
出处
《厦门大学学报（自然科学版）》
CAS
CSCD
北大核心
1993年第2期177-181,共5页
Journal of Xiamen University：Natural Science
基金
国家自然科学基金
关键词
还原羰基化
钯
邻菲咯啉
催化剂
Reductive Carbonylation, Nitrobenzene, Palladium, Phenanthroline, Phenylurethane
