Reduction of Nitrobenzene with Hydrazine Hydrate Catalyzed by Acid-Treated Activated Carbon

Activated carbons, which were modified by chemical treatment in aqueous solutions of HNO3, HCl, and H2SO4 or in gaseous N2 and H2, have been tested as catalysts in the reduction of nitrobenzene using hydrazine hydrate as hydrogen donor. Fourier transform infrared spectroscopy analysis and Boehm titration reveal that the chemical treatment leads to the formation of various oxygen functional groups on the surface of the activated carbon. These oxygen functional groups can induce the decomposition of hydrazine hydrate and influence the adsorption of nitrobenzene on the surface of the activated carbon. The catalytic activity is correlated to that of the oxygen functional groups, which suggests that an abundance of surface oxygen functional groups is favourable for this reaction. The activated carbon treated by hydrochloric acid had the largest amount of oxygen functional groups and exhibited the highest activity for nitrobenzene reduction to aniline.

摘要以水合肼为还原剂, 采用硝酸 盐酸 硫酸及氮气或氢气氛处理的活性炭为催化剂, 考察了其催化硝基苯还原反应性能.结果表明, 经化学处理后, 活性炭表面形成了各种含氧官能团, 它们可引发水合肼分解, 并影响硝基苯的吸附. 活性炭表面形成的含氧官能团越多, 其催化硝基苯还原速率越快. 其中经盐酸处理的活性炭表面形成的含氧官能团最多, 因而表现出最高的硝基苯还原活性.

Oxygen functional groups formed on activated carbon treated by inorganic acids can induce the decomposition of N2H4·H2O, influence the adsorption of C6H5NO2 and increase the activity for C6H5NO2 reduction to C6H5NH2.Figure optionsDownload as PowerPoint slide