钴酸镧基钙钛矿耦合非热等离子体催化转化CO_(2)的实验研究

Experimental study on catalytic CO_(2) conversion by LaCoO_(3)-based perovskites coupled with non-thermal plasma

CO_(2)的减排与利用是实现碳达峰和碳中和目标的重要途径.本文通过溶胶凝胶法将Sr和Zr掺入钙钛矿型LaCoO_(3)结构中,合成了一系列钙钛矿催化剂,包括LaCoO_(3)、La_(0.9)Sr_(0.1)CoO_(3-σ)、La_(0.9)Sr_(0.1)Co_(0.9)Zr_(0.1)O_(3+σ)和La_(0.9)Sr_(0.1)Co_(0.9)Zr_(0.1)O_(3),并考察了非热等离子体催化还原CO_(2)为CO和CH4的性能.同时在A位掺杂Sr和B位掺杂Zr的催化剂(La_(0.9)Sr_(0.1)Co_(0.9)Zr_(0.1)O_(3))反应活性最高,其CO_(2)转化率为28.7%,分别比空管和LaCoO_(3)提高了23.7%和10.7%.结合XRD、SEM、Raman、XPS、H_(2)-TPR以及CO_(2)-TPD等表征结果,发现相比LaCoO_(3)催化剂,La_(0.9)Sr_(0.1)Co_(0.9)Zr_(0.1)O_(3)催化剂结构稳定,具有较小的粒径、更大的比表面积、良好的孔道结构以及丰富的氧空位,有利于吸附活化更多的CO_(2),并显著促进了等离子催化转化CO_(2).该催化剂的开发对等离子体催化体系高效应用于CO_(2)的减排与利用具有积极意义.

The reduction and utilization of CO_(2)is one of the important ways to achieve carbon peaking and carbon neutrality.In this work,a series of perovskite catalysts by the Sr and Zr cations doping into the LaCoO_(3)structure,including LaCoO_(3),La_(0.9)Sr_(0.1)CoO_(3-σ),La_(0.9)Sr_(0.1)Co_(0.9)Zr_(0.1)O_(3+σ),and La_(0.9)Sr_(0.1)Co_(0.9)Zr_(0.1)O_(3),were synthesized by a sol-gel strategy and investigated the plasma-catalytic CO_(2)reduction to CO and CH4.The highest performances were obtained when the catalysts(La_(0.9)Sr_(0.1)Co_(0.9)Zr_(0.1)O_(3))were co-doped with the Sr and Zr cations at the A sites and B sites,respectively.The CO_(2)conversion rate(28.7%)of the La_(0.9)Sr_(0.1)Co_(0.9)Zr_(0.1)O_(3)catalysts was better than that of the empty reactor(23.7%)and LaCoO_(3)(10.7%).The XRD,SEM,Raman,XPS,H_(2)-TPR,and CO_(2)-TPD results showed that compared with LaCoO_(3)catalysts,the La_(0.9)Sr_(0.1)Co_(0.9)Zr_(0.1)O_(3)catalysts with the stable architecture presented the smaller particle size,larger specific surface areas,promising pore structure,and abundant oxygen vacancies,which facilitated the adsorption and activation of more CO_(2)and thus contributed to the plasma-catalytic conversion of CO_(2).The development of the catalysts is of profound significance for the application of high-efficiency plasma-catalytic system to CO_(2)reduction and utilization.