高分散铈物种催化剂的可控制备及其光催化还原CO2为CH4的促进机制
Highly dispersed Ce species on g-C3N4 for the enhanced selectivity of photocatalytic CO2 reduction to CH4
赵馨 1邹伟欣 2董林2
作者信息
- 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. 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;江苏省机动车尾气污染控制重点实验室,南京大学,南京,210023
- 折叠
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CO2的反应性能.在本工作中,使用配位法将铈(Ce)物种嵌入g-C3N4的三嗪环(CeCN-urea-N2)中,相比于浸渍法制备的CeCN-N2样品,CeO2的颗粒尺寸变小,界面之间的相互作用增强.结果表明,CeCN-urea-N2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CO2分子发生反应.因此,CeCN-urea-N2样品可以形成更多·CO2-自由基,进而与表面H2O/OH产生质子化过程,提高了光催化还原CO2为CH4的选择性.
Abstract
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-C3N4(CeCN-urea-N2)for CO2 photoreduction.On CeCN-urea-N2,Ce species were highly dispersed,while for the impregnated sample of CeCN-N2,agglomerated CeO2 particles were found.The highly dispersed Ce species on g-C3N4 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 CO2 molecules,leading to more CO2-radicals on CeCN-urea-N2,which were attacked by the surface enriched protons of H2O/OH to enhance CH4 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CO2/内建电场/CH4选择性Key words
highly dispersed Ce/CO2 photoreduction/in-built electronic field/CH4 selectivity引用本文复制引用
基金项目
国家自然科学基金(62375120)
国家自然科学基金(21972062)
出版年
2024
NETL
NSTL
万方数据