C_3N_4/AC结构对二氯乙烷催化热裂解性能的影响  

Effect of C_3N_4/AC Structure on Catalytic Pyrolysis Performance of Dichloroethane

作　　者：刘政[1] 孙玺[2] 张健[1] 秦玉才[1] 宋丽娟[1] Liu Zheng;Sun Xi;Zhang Jian;Qin Yucai;Song Lijuan(Key Laboratory of Petrochemical Catalytic Science of Liaoning Province,Liaoning Shihua University,Fushun Liaoning 113001,China;College of Chemistry and Chemical Engineering,Lanzhou University,Lanzhou Gansu 730000,China)

机构地区：[1]辽宁石油化工大学辽宁省石油化工催化科学与技术重点实验室,辽宁抚顺113001 [2]兰州大学化学与化工学院,甘肃兰州730000

出　　处：《石油化工高等学校学报》2018年第6期17-23,共7页Journal of Petrochemical Universities

基　　金：国家自然科学基金资助项目(U1662135;21376114)

摘　　要：采用等摩尔浸渍法,利用含相同物质的量氮的氰胺、硫脲、尿素作为前驱体,以活性炭为载体制备C_3N_4/AC催化剂。运用固定床反应器评价了C_3N_4/AC催化剂对1,2-二氯乙烷催化热裂解的反应性能,并采用SEM、XRD、BET、XPS、TGA表征了催化剂形貌、结构及表面组成等性质。结果表明,0.110 mol前驱体制备的催化剂初始活性和选择性都接近100%,但催化剂稳定性差异明显,以尿素为前躯体制备的C_3N_4/AC催化剂稳定性最高。然而,通过降低前驱体负载量合成的C_3N_4/AC催化剂结构与形貌及催化裂解性能均有差异。当负载量降到每10 g活性炭负载0.057 mol的氮时,以尿素为前躯体制备的C_3N_4/AC催化剂对1,2-二氯乙烷裂解催化活性较好、稳定性最高。不同前驱体合成的氮化碳形貌不同,硫脲、氰胺虽然可获得更多的氮化碳,但是所形成的氮化碳容易团聚从而影响了催化活性,尿素是用于该催化剂合成最优的前驱体。The C3N4/AC catalyst was prepared by using the same nitrogen content of cyanamide,thiourea,urea as precursor and activated carbon as the carrier. The reaction performance of C3N4/AC catalyst for the catalytic pyrolysis of 1,2-dichloroethane was evaluated by using fixed bed reactor,and the properties of catalyst structure were characterized by SEM,XRD,BET,XPS and TGA. The results showed that the initial activity and selectivity of the catalyst prepared from 0.110 mol precursor were close to 100%,but the stability of the catalyst was different obviously. The catalyst synthesized with urea as precursor had the highest catalyst stability compared with the other two precursors. However,the catalysts synthesized by using low loading of precursors showed differences on the catalytic performance. The structure and morphology of the catalysts with low loading of precursor were investigated. The results showed that when the load was reduced to 0.057 mol,the C3N4/AC catalyst prepared with urea had the highest catalytic activity for dehydrochlorination of 1,2-dichloroethane and the best stability.The different morphologies of carbon nitride was synthesized by different precursors. The carbon nitride productivity of thiourea and cyanamide is higher than urea but is more easily to form bulk carbon nitride which will result in poor stability. After all,urea is the optimal precursor for the C3N4/AC catalyst for dehydrochlorination of 1,2-dichloroethane.

关 键 词：前躯体 C3N4/AC 1 2-二氯乙烷 催化热裂解 

分 类 号：TE624[石油与天然气工程—油气加工工程] TQ4-26[化学工程]