Pt/WN based fuel cell type methanol sensor

Methanol detection is known to be a challenge using the normal Pt/C based gas sensor. This is primarily due to CO poisoning of the Pt active sites, resulting in an irreversible loss of sensor performance. In this paper, a novel fuel cell type gas sensor based on platinized mesoporous tungsten nitride (Pt/WN) is fabricated by employing a hot-press method. The device shows considerable performance for methanol detection at room temperature without external potential applied. The mesoporous WN is prepared through a simple solid-state method with subsequent ammonolysis. An ethylene glycol reduction method is applied to load Pt nanoparticles on WN or on carbon blacks. Results show that Pt/WN gas sensor has the sensitivity of 0.037 mu A/ppm, which is four times higher than that of the Pt/C counterpart. In addition, replacing carbon with WN will increase the response to to methanol with excellent selectivity and stability. The synergistic effect between WN and Pt may play an important role. This investigation shows the potential of tungsten metal nitride in the gas sensor device reported; this offers a new way to change the selectivity of gas sensors using suitably chosen support materials.