FeCl_3/PVP胶体催化水合肼还原硝基苯

以聚乙烯吡咯烷酮(PVP)为保护剂,采用水热合成法制备了FeCl3/PVP胶体催化剂,通过XRD和TEM方法对催化剂的形貌与结构进行了表征;考察了催化剂的制备条件(水热时间、PVP与FeCl3的摩尔比)和反应条件(反应温度、水合肼用量和催化剂用量)对还原反应的影响。实验结果表明,在PVP与FeCl3摩尔比1∶40、100℃下水热2h制得的胶体稳定性好、分散度高,其胶粒呈70～90nm的棒状结构。该胶体催化剂在催化水合肼还原硝基苯的反应中表现出很高的催化活性,在反应温度80℃、反应时间80min、硝基苯用量4.89mmol、无水乙醇用量5mL、FeCl3/PVP胶体催化剂用量2.0mL(nFe=0.150 0mmol)、n(水合肼)∶n(硝基苯)=2.5的条件下,苯胺收率可达100%。

Reduction of Nitrobenzene with Hydrazine Hydrate over FeCl3/PVP Colloidal Catalyst

FeCl3/polyvinylpyrrolidone(PVP) colloidal catalysts were prepared through a hydrothermal process with PVP as protective agent and used in reduction of nitrobenzene with hydrazine hydrate to aniline.Structures and morphologies of the FeCl3/PVP colloidal catalysts were characterized by means of XRD and TEM.Effects of the hydrothermal time and the PVP dosage on performance of the FeCl3/PVP colloidal catalysts in the reduction were investigated.The effects of reaction temperature,catalyst dosage and hydrazine hydrate dosage on aniline yield were studied.The high-stable,high-dispersive and club-shaped FeCl3/PVP colloidal catalyst with a size of 70-90 nm was prepared under hydrothermal treatment conditions of n(PVP)∶n(FeCl3) 1∶40,temperature 100 ℃ and time 2 h.Under the optimal reaction conditions: reaction temperature 80 ℃,reaction time 80 min,nitrobenzene dosage 4.89 mmol,absolute alcohol dosage 5 mL,FeCl3/PVP colloidal catalyst dosage 2.0 mL(nFe 0.150 0 mmol) and n(hydrazine hydrate)∶n(nitrobenzene) 2.5,yield of aniline could reach 100%.