La1-x AgxCoO3钙钛矿催化剂的制备及烟碳颗粒催化燃烧性能

摘要

A series of perovskite oxides La1-x Agx CoO3 were synthesized by a citrate-based sol-gel method and characterized by XRD and H2-TPR. The XRD results showed that in the Ag-containing samples,parts of Ag substituted La3+ at A-site while others existed in the form of metal on the surface of the perovskites. The H2-TPR results revealed that the low-temperature redox ability of the samples doped with Ag was observably enhanced. La1-xAgxCoO3 catalysts were tested for carbon(Printex-U and cigarette soot)oxidation under tight-contact mode. LaCoO3 catalysts exhibited moderately low ignition temperature for Printex-U oxidation. The catalytic activities of LaCoO3 catalysts doped with Ag were progressively enhanced with the increase of Ag contents. Similarly,La1-x Agx CoO3 catalysts exhibited excellent activities for cigarette soot oxidation,but their activities were less affected by Ag content. La1-x Agx CoO3 catalysts were added to tobacco surfaces and the effect of catalysts on the maximum combustion temperature of cigarette was investigated. The results showed that when the adding amount of the catalyst was 5% of tobacco mass,the maximum combustion temperature of cigarette reduced by 28 ℃.%采用柠檬酸溶胶-凝胶法制备La1-x Agx CoO3系列钙钛矿催化剂，并对催化剂进行XRD和H2-TPR表征。XRD结果表明，LaCoO3钙钛矿中掺杂Ag，部分Ag进入晶格，同时部分Ag以单质形式存在于钙钛矿表面。H2-TPR结果表明，Ag的掺杂有利于提高LaCoO3催化剂的低温还原性能。在此基础上，考察催化剂在紧密接触条件下对标准碳和烟碳的催化燃烧性能，发现LaCoO3钙钛矿可降低标准碳的起燃温度，在LaCoO3催化剂中掺入Ag，标准碳的燃烧温度进一步降低。催化剂对标准碳的催化燃烧活性随着Ag添加量的增加而逐渐增加。La1-x Agx CoO3催化剂对烟碳的催化燃烧具有较好活性，但Ag含量对催化剂在烟碳催化燃烧中的活性影响较小。为了在烟碳催化燃烧性能和降低卷烟燃烧温度之间建立关联，将催化剂添加到烟丝表面，考察催化剂的添加对卷烟最高燃烧温度的影响，结果表明，当催化剂添加量为烟丝质量的5%时，卷烟的最高燃烧温度可降低28℃。