수소연료전지용 탄탈륨 탄화물에 대한 암모니아 분해반응

Abstract

Tantalum carbide crystallites which is to be used for <TEX>$H_2$</TEX> fuel cell has been synthesized via a temperature-programmed reduction of <TEX>$Ta_2O_5$</TEX> with pure <TEX>$CH_4$</TEX>. The resultant Ta carbide crystallites prepared using two different heating rates and space velocity exhibit the different surface areas. The <TEX>$O_2$</TEX> uptake has a linear relation with surface area, corresponding to an oxygen capacity of <TEX>$1.36{\times}10^{13}\;O\;cm^{-2}$</TEX>. Tantalum carbide crystallites are very active for hydrogen production form ammonia decomposition reaction. Tantalum carbides are as much as two orders of magnitude more active than Pt/C catalyst (Engelhard). The highest activity has been observed at a ratio of <TEX>$C_1/Ta^{{\delta}+}=0.85$</TEX>, suggesting the presence of electron transfer between metals and carbon in metal carbides.