洁净煤技术

2020, v.26;No.128(04) 162-167

[打印本页] [关闭]
本期目录(Current Issue) | 过刊浏览(Past Issue) | 高级检索(Advanced Search)

Pt、Cu共改性TiO_2选择性光催化还原CO_2制CH_4
Selective photocatalytic reduction of CO_2 into CH_4 by Pt and Cu co-modified TiO_2

李长华;赵江婷;熊卓;赵永椿;
LI Changhua;ZHAO Jiangting;XIONG Zhuo;ZHAO Yongchun;National Energy Group Jiangxi Power Generation Corporation;State Key Laboratory of Coal Combustion,Huazhong University of Science and Technology;

摘要(Abstract):

光催化还原CO_2是具有前景的可再生能源技术,但由于光生电子-空穴对的快速复合和对可见光的有限利用,Ti O_2表现出较低的光催化反应效率,为了提高Ti O_2光催化还原CO_2的效率,用金属改性Ti O_2是一种有效的方式。笔者通过化学还原法将Pt和Cu_2O纳米颗粒沉积在锐钛矿TiO_2晶体表面,系统研究了Pt、Cu共改性对Ti O_2光催化还原CO_2性能的影响。光催化试验结果表明,Pt沉积有利于生成CH_4和H_2,而Cu_2O会抑制H_2的生成,且对CH_4的选择性低于Pt。Pt和Cu_2O同时沉积在Ti O_2晶体上时,H_2的生成受到抑制,CO_2被选择性地还原为CH_4,选择性达96.6%。催化剂表征结果表明,Pt能捕获光生电子,从而提高催化剂上的电子密度,有利于多电子还原反应发生,高选择性地生成CH_4。Cu_2O提高了催化剂对CO_2的化学吸附能力,同时对水的吸附能力较弱,从而抑制H_2的生成,提高了光生电子对CO_2还原的选择性。此外,反应后的Pt-Cu/Ti O_2中Cu2O几乎被完全还原为Cu,这可能是由于在光催化反应过程中,Pt沉积可促进光生电子向Cu_2O迁移,在Cu_2O还原为Cu的同时为光催化还原反应提供更多的电子,有利于CH_4的选择性生成。因此,Pt-Cu/TiO_2催化剂可将CO_2选择性地还原为CH_4。经3次循环试验,催化剂的活性未降低,具有良好的稳定性。
Photocatalytic reduction of CO_2 is a challenging renewable energy production technology.However,due to the rapid recombination of photogenerated electron hole pairs and the limited utilization of visible light,TiO_2 shows low photocatalytic reaction efficiency.In order to improve the efficiency of photocatalytic reduction of CO_2 by Ti O_2,it is an effective way to modify TiO_2 by metal.In this paper,Pt and Cu_2O nanoparticles were co-deposited on the surface of TiO_2 nanocrystals by chemical reduction method.The influence of Pt and Cu co-modification on the photocatalytic reduction of CO_2 by Ti O_2 was systematically studied.The experimental results show that Pt deposition tends to promote the production of CH_4 and H_2.However,Cu_2O can suppress H2 production and exhibites lower CH_4 selectivity than that of Pt.Furthermore,after co-deposition of Pt and Cu_2O on Ti O_2 crystal,the formation of H_2 is inhibited,and CO_2 is selectively converted to CH_4,with a selectivity of 96.6%.The characterization experiments and a series of photocatalytic reduction selectivity experiments show that Pt can not only capture the photogenerated electrons,but also improve the electron density on the catalyst,which is conducive to the multi-electron reduction reaction and the formation of CH_4 with high selectivity.Cu_2O enhances the chemical adsorption of CO_2 on TiO_2 and inhibites the adsorption of water,thus the formation of H_2 is inhibited and the selectivity of photogenerated electrons for CO_2 reduction is improved.In addition,Cu_2O in Pt-Cu/TiO_2 after the reaction is almost completely reduced to Cu,which may be caused by the process of photocatalytic reaction,Pt deposition can promote the transfer of photogenerated electrons to Cu_2O. This phenomenon can provide more electrons for the photocatalytic reduction while reducing Cu_2O to zero valent Cu,which is conducive to the selective generation of CH_4.Therefore,Pt-Cu/TiO_2 catalyst can selectively reduce CO_2 to CH_4.After three cycles of tests,the activity of the catalyst is not reduced and has good stability.

关键词(KeyWords): CO_2光催化还原;TiO_2;选择性;共沉积;CH4
CO_2 photocatalytic reduction;TiO_2;selectivity;co-deposited;CH4

Abstract:

Keywords:

基金项目(Foundation): 国家自然科学基金资助项目(51706082,U1610110)

作者(Author): 李长华;赵江婷;熊卓;赵永椿;
LI Changhua;ZHAO Jiangting;XIONG Zhuo;ZHAO Yongchun;National Energy Group Jiangxi Power Generation Corporation;State Key Laboratory of Coal Combustion,Huazhong University of Science and Technology;

Email:

DOI: 10.13226/j.issn.1006-6772.20032011

参考文献(References):

文章评论(Comment):

序号(No.) 时间(Time) 反馈人(User) 邮箱(Email) 标题(Title) 内容(Content)
反馈人(User) 邮箱地址(Email)
反馈标题(Title)
反馈内容(Content)
扩展功能
本文信息
服务与反馈
本文关键词相关文章
本文作者相关文章
中国知网
分享