热燃烧式瓦斯传感器催化剂失活机理研究

热燃烧式催化瓦斯传感器是煤矿矿井瓦斯监控系统的核心部件,用于检测瓦斯体积分数,实现风电闭锁功能。由于矿井环境条件恶劣,常常使瓦斯传感器表现出稳定性能差,校准期短等缺点,一直是困扰热燃烧式催化瓦斯传感器应用的难题。通过研究热燃烧式催化瓦斯传感器的失活模式及响应分析,重点探讨了铂催化剂失活的3种机理:烧结、结焦、中毒,建立了催化剂失活速率方程,提出了添加Pt-Pd复合催化剂的方法来改善催化剂失活,改进后,传感器的稳定性得到了明显提高。

Study on catalyst's activation vanishing mechanism of burning type gas sensors

Burning type catalyzing gas sensors are the devices of the gas monitoring system in coal mines,which realizes the auto on-off of the ventilation system based on detecting the gas volume fraction.Due to the bad environmental conditions in the mines,gas sensors are limited by the shortcomings of low stability and short calibration periods,which has been a problem to limit the sensors'application.By studying the thermal firing type gas sensors'activation vanishing modes and analyzing the responses,three activation vanishing mechanisms of the Pt catalyst are major discussed,including the firing,coking and toxicosix mechanism.The catalyst's activation vanishing velocity function is built up.The activation vanishing situation is improved by adding the Pt-Pd complex catalyst.Experimental results demonstrate that the sensor's stability is apparently improved.