Iron nitride catalysts preparation

Iron and its compounds (carbide, nitride), as well as ruthenium, cobalt, rhodium, and molybdenum compounds (sulfide, carbide), are used most frequently to produce high-molecular-weight hydrocarbons. Iron can be prepared as a high-surface-area catalyst (==300 m /g) even without using a microporous oxide support. 7-AI2O3, Ti02, and silica are frequently used as supports of the dispersed transition-metal particles. Recently zeolites, as well as thorium oxide and lanthanum oxide, have... 

Today s most stable Me-N-C catalysts are the Me-PANI-C catalysts of Zelenay s group [11]. In order to obtain the nitrogen precursor, aniline is impregnated on a carbon support and then an oxidative polymerization is initiated in the presence of iron chlorine and/or cobalt nitride (both in various concentrations). As oxidant, either hydrogen peroxide or ammonium peroxydisulfate can be used [38]. In order to obtain the final catalysts, two heat treatment steps are performed, both at the same temperature and both followed by an acid leaching. Best results were obtained for catalysts prepared at 900 °C [29]. These catalysts were stable for 4 weeks of FC run under potentiostatic conditions (0.4 V) and even showed increasing currents... 

Shultz, Seligman, Shaw, and Anderson (5) attempted to prepare nitrides by treating raw (oxide) iron catalysts directly with ammonia. An analogous reaction, the formation of iron carbides by treatment of raw precipitated catalysts with carbon monoxide or synthesis gas, can be carried out at temperatures between 200° and 325°C. However, ammonia treatment of a precipitated catalyst (Fe203-Cu0-K2C03, Bureau of Mines number P3003.24) at 300°, 350°, and 400°C. resulted... 

---