NI-CO-B非晶态合金催化剂用于氯代硝基苯液相加氢制氯代苯胺  

Liquid-Phase Hydrogenation of Chloronitrobenzene to Chloroaniline over Ni-CoB Amorphous Alloy Catalyst

作　　者：严新焕[1] 孙军庆[1] 徐颖华[1] 杨建峰[1] 

机构地区：[1]浙江工业大学绿色化学合成技术国家重点实验室培育基地,浙江杭州310032

出　　处：《催化学报》2006年第2期119-123,共5页

基　　金：国家自然科学基金(20276071);浙江省重大自然科学基金(ZE0102)资助项目

摘　　要：用化学还原法制备了NI-CO-B非晶态合金催化剂,并采用透射电子显微镜、扫描电子显微镜、选区电子衍射、X射线衍射、X射线能谱和差热-热重分析等表征手段研究了催化剂的非晶性质和原子组成等.将此催化剂用于邻氯硝基苯和3,4-二氯硝基苯的液相催化加氢反应,结果表明,当CO/(CO+NI)=0.5(摩尔比)时,NI-CO-B催化剂具有较好的加氢性能和较高的抑制脱卤性能.在不加脱卤抑制剂的情况下,两种氯代硝基苯的转化率均接近100%,脱卤率分别为1.12%和0.42%,优于使用NI-B和CO-B非晶态合金催化剂时的结果.还讨论了将CO引入到NI-B非晶态合金催化剂时对其性能的影响.The Ni-Co-B bimetallic amorphous alloy with Co/（Co ＋ Ni） molar ratio varying from 0 to 1 was prepared by chemical reduction of N i（NO3）2 and Co（NO3）2 with KBH4 in solution. Its amorphous structure was verified by X-ray powder diffraction and selected area electron diffraction. The thermostability of the amorphous alloy was characterized by thermogravimetry-differential thermal analysis. Scanning electron microscopy and transmission electron microscopy were used to determine its morphology and particle size. The Ni-Co-B amorphous catalyst with a Co/（Co＋ Ni） molar ratio of 0.5 exhibits a much higher activity and selectivity than the Ni-B and Co-B catalysts in the liquid-phase hydrogenation of chloronitrobenze to chloroaniline. The maximum conversion of both o-chloronitrobenzene and 3,4-dichloronitrobenzene reaches 99.9 % , whereas the dechlorination of chloroaniline was 1.12 % and 0.42 %, respectively, showing a good potential for industrial applications. The higher activity and selectivity of the Ni-Co-B catalyst can be attributed to the electron donation from the alloying B and metallic CO to the metallic Ni. Following this, the B and Co atoms become electron-deficient whereas the Ni atom becomes electron-enriched, which can activate the N=O bond, inhibit the hydrodechlorination of chloronitrobenzene, and increase the thermostability of the amorohous alloy.

关 键 词：镍 钴 硼 非晶态合金 邻氯硝基苯 3 4-二氯硝基苯 催化加氢 氯代苯胺 

分 类 号：O643.32[理学—物理化学]