Catalytic Combustion of Methane over Tin Dioxide Supported Silver Catalysts

考察了Ag/SnO2系列催化剂对甲烷燃烧反应的催化活性,并采用XRD、BET、XPS、TEM和TPR等技术对催化剂中银的存在状态进行了表征.结果表明,Ag/SnO2体系具有较高的甲烷催化燃烧活性,样品的载银量不同,银物种的存在状态及样品的比表面和催化性能也很不相同.Ag/Sn原子比低于0.20的样品中,银物种为分散态氧化银及晶相氧化银,这些样品具有较高的比表面和催化活性;载银量继续增加时,金属银开始出现并成为主要的银物种,样品的比表面和催化活性也随之迅速下降.Ag/Sn原子比为0.20的样品具有最高的催化活性.Catalytic property of Ag/SnO2 catalysts for the combustion of methane was investigated and the state of silver was characterized by using XRD, BET, XPS, TEM and TPR. The results show that Ag/SnO2 system is quite active for the catalytic combustion of methane. When Ag/Sn atomic ratio is lower than 0.20, the main silver species is silver oxide existing in both dispersed state and crystal phase, and all the corresponding catalysts show relatively large surface areas and high catalytic activities. If silver content further increases, metallic silver shows up and becomes the main silver species, and the surface areas as well as the catalytic activities of the samples decrease dramatically. The sample with a Ag/Sn atomic ratio of 0.20 has the highest activity.国家自然科学基金SCI(E)中文核心期刊要目总览(PKU)中国科学引文数据库(CSCD)89850-8541