不同晶面Co基催化剂上CO活化行为研究  

CO dissociation over cobalt-based catalysts with different crystal facets

作　　者：卢文丽 王俊刚[1] 孙德魁[1] 马中义[1] 陈从标[1] 侯博[1] 王宝俊[3] 李德宝[1] LU Wen-li;WANG Jun-gang;SUN De-kui;MA Zhong-yi;CHEN Cong-biao;HOU Bo;WANG Bao-jun;LI De-bao(State Key Laboratory of Coal Conversion,Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001,China;University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi Province,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]中国科学院山西煤炭化学研究所煤转化国家重点实验室,山西太原030001 [2]中国科学院大学,北京100049 [3]太原理工大学煤科学与技术教育部和山西省重点实验室,山西太原030024

出　　处：《燃料化学学报》2022年第5期583-590,共8页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(21736007,21872162,21902170);山西省重点研发计划(201903D121039,202103021224444)资助。

摘　　要：本研究用溶剂热法合成了三种暴露不同晶面的Co基催化剂,排除载体、助剂、晶粒尺寸等参数的影响,通过程序升温脱附、原位拉曼光谱、原位漫反射红外光谱等表征手段和化学瞬变反应技术,对不同晶面Co催化剂在费托反应过程中CO活化行为进行了研究。结果表明,CO的活化在不同晶面的Co基催化剂上具有结构敏感性。Co(10-11)晶面上CO以直接解离的方式进行活化,且CO解离生成的碳物种部分形成积炭,其余碳物种加氢生成CH_(x);Co(0001)晶面上CO以氢助解离的方式活化,大量解离为积炭,少量碳物种氢化为CH_(x);Co(11-20)晶面上CO直接解离,该催化剂上CO弱解离得到微量的积炭,其余碳物种在氢的存在下生成微量的CH_(x)中间体。The way of CO dissociation,as a crucial step in the Fischer-Tropsch(F-T)synthesis process,has been a subject of intense debate in literature.In order to understand the F-T synthesis reaction behavior of cobalt catalysts with different crystal planes,the CO dissociation behavior over three cobalt catalysts with different crystal facets during F-T reaction was investigated by excluding the influence of support,promoter and particle size.The catalysts were characterized by temperature programmed desorption(TPD),diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS),in-situ Raman and Chemical Transient Kinetics(CTK).The results show that CO on the Co(10-11)is activated by direct dissociation,among which small amount of carbonaceous species generated by CO dissociation forms carbon depositing on the catalyst surface under F-T reaction condition,and a large amount of carbonaceous species are hydrogenated to CH_(x) species.The CO on the Co(0001)crystal surface is activated predominantly by hydrogen-assisted dissociation,a large fraction of CO is dissociated into carbon deposition and a tiny fraction of CO is hydrogenated into CH_(x).CO is directly dissociated on the Co(11-20)plane.The weak dissociation of CO on this catalyst results in a trace amount of carbon deposition,and a trace amount of CH_(x) intermediate in the presence of hydrogen.

关 键 词：费托合成 Co基催化剂 CO活化 化学瞬变反应技术 

分 类 号：O643.36[理学—物理化学]