고진공계에서의 열탈착실험을 통하여 MoO_3촉매상에서의 CH_3OH 분해 및 부분산화반응에 관한 연구를 수행하였다. CH_3OH는 촉매표면에 methoxy (-OCH_3)와 수소원자 (-H) 의 형태로 흡착되어 있다가 흡착 수소원자가 methoxy와 재결합하면서 425K에서 CH_3OH로 탈착하였으며, methoxy로부터 수소원자가 떨어져 나가면서 545K에서 HCHO가 탈착되었다. 이때 반응에 의해서 생성된 물은 428K에서 탈착하는 α-피크와 586K에서 탈착하는 β-피크를 보였으며, α-피크는 표면에 형성된 hydroxyl에 기인하는 탈착피크, β-피크는 methoxy가 수소를 잃으면서 HCHO의 형태로 촉매표면에서 탈착하면서 남긴 표면수소원자와 격자산소가 반응하여 생성된 물에 각각 기인하는 것으로 보였다. 선흡착된 산소원자는 CH_3OH의 분해흡착을 촉진시킴으로써 CH_3OH의 흡착량을 중가시킨 반면, 선흡착된 물은 분해흡착하여 CH_3OH의 흡착점을 점유함으로써 CH_3OH의 흡착량을 감소시켰다.

The dissociation and partial oxidation of CH_3OH on polycrystalline MoO_3 powder catalyst were studied using thermal desorption spectrometry(TDS) under high vacuum condition. CH_3OH was dissociatively adsorbed on MoO_3 in the forms of surface methoxy(-OCH_3) and atomic hydrogen(-H). CH_3OH desorbed at 425 K via the re-association of methoxy and adsorbed hydrogen atom, and HCHO desorbed at 545 K through the bond breakage of C-H in methoxy. Water TDS spectra showed two desorption peaks, that is, α-peak at 428 K and β-peak at 586 K. It was suggested that α-peak was due to the hydroxyl formed on MoO_3 surface during the dissociation of CH_3OH, and that β-peak was from the association of lattice oxygen and surface hydrogen atom formed by the bond breakage of C-H in methoxy. Pre-adsorbed oxygen on the surface of MoO_3 catalyst increased the amount of adsorption of CH_3OH by promoting the dissociation of CH_3OH on the surface, whereas pre-adsorbed water decreased the amount of adsorption of CH_3OH by blocking of adsorption sites for CH_3OH.