高分散铈物种催化剂的可控制备及其光催化还原CO_(2)为CH_(4)的促进机制  

Highly dispersed Ce species on g-C_(3)N_(4) for the enhanced selectivity of photocatalytic CO_(2)reduction to CH_(4)

作　　者：赵馨 邹伟欣 董林 ZHAO Xin;ZOU Weixin;DONG Lin(State Key Laboratory of Pollution Control and Resource Reuse,School of the Environment,Nanjing University,Nanjing,210023,China;Jiangsu Key Laboratory of Vehicle Emissions Control,Nanjing University,Nanjing,210023,China)

机构地区：[1]南京大学环境学院,污染控制与资源化研究国家重点实验室,南京210023 [2]江苏省机动车尾气污染控制重点实验室,南京大学,南京210023

出　　处：《环境化学》2024年第10期3480-3488,共9页Environmental Chemistry

基　　金：国家自然科学基金(62375120,21972062)资助.

摘　　要：调控金属氧化物与载体间的界面作用可以有效提升光催化还原CO_(2)的反应性能.在本工作中,使用配位法将铈(Ce)物种嵌入g-C_(3)N_(4)的三嗪环(CeCN-urea-N_(2))中,相比于浸渍法制备的CeCN-N_(2)样品,CeO_(2)的颗粒尺寸变小,界面之间的相互作用增强.结果表明,CeCN-urea-N_(2)样品中存在高度分散的Ce物种,同时理论计算表明,Ce原子的f电子转移到七氮环上,促进光生电子流入Ce位点,并与吸附在其上的CO_(2)分子发生反应.因此,CeCN-urea-N_(2)样品可以形成更多·CO_(2)−自由基,进而与表面H_(2)O/OH产生质子化过程,提高了光催化还原CO_(2)为CH_(4)的选择性.Enhanced interfacial interaction between metal oxide and support is a promising alternative to photocatalysis.In the work,the coordination method was used to synthesize the photocatalyst of heptazine rings chelating Ce atoms on g-C_(3)N_(4)(CeCN-urea-N_(2))for CO_(2) photoreduction.On CeCN-urea-N_(2),Ce species were highly dispersed,while for the impregnated sample of CeCN-N_(2,)agglomerated CeO2 particles were found.The highly dispersed Ce species on g-C_(3)N_(4) was beneficial for the generation of in-built electronic field,i.e.,f electrons of Ce atoms transferred to heptazine rings.Therefore,the photogenerated electrons flowed into Ce and reacted with the adsorbed CO_(2) molecules,leading to more·CO_(2)−radicals on CeCN-urea-N_(2),which were attacked by the surface enriched protons of H_(2)O/OH to enhance CH_(4) selectivity,confirmed by the in situ DRIFTS result.The work provides a simple way to design efficient photocatalysts.

关 键 词：高分散铈物种 光催化还原CO_(2) 内建电场 CH_(4)选择性 

分 类 号：X-1[环境科学与工程] O6[理学—化学]