Page 141 - 《精细化工》2022年第5期
P. 141
第 39 卷第 5 期 精 细 化 工 Vol.39, No.5
2022 年 5 月 FINE CHEMICALS May 2022
水处理技术与环境保护
表面磷酸化 CeO 选择性还原 NO 及其碱金属耐受性
2
*
李 顺,胡方方,王闻之,蔡思翔 ,姜 宏
(海南大学 材料科学与工程学院,南海海洋资源利用国家重点实验室,海南省特种玻璃重点实验室,海南
海口 570228)
摘要:以 Ce(NO 3 ) 3 •6H 2 O 和(NH 4 ) 3 PO 4 •3H 2 O 为原料,采用浸渍法制备了磷酸化 CeO 2 催化剂。以 NH 3 为还原剂,
考察了磷酸化 CeO 2 催化剂氨选择性催化还原(NH 3 -SCR)NO 的脱硝性能。利用 XRD、N 2 吸附-脱附、XPS、
NH 3 -TPD、原位漫反射红外光谱对催化剂结构和性能进行了表征。结果表明,在 250~500 ℃范围内,磷酸化
CeO 2 催化剂(CeP 0.05 )使 NO 的转化率在 90%以上,且在碱金属和碱土金属中毒后,在 300~400 ℃范围内,磷
酸化 CeO 2 催化剂使 NO 的转化率仍保持在 80%以上。磷酸化 CeO 2 催化性能的增强可归因于酸位点数量的增加,
3+
尤其是 Brønsted 酸位点数量的增加。磷酸化改性产生更多的 Ce 和化学吸附氧,提高了催化剂的氧化还原能力。
当碱金属沉积在催化剂上时,碱金属被诱导迁移到磷酸化 CeO 2 的表面与 Ce—O—P 碱捕获位点结合,从而阻止
4+
碱金属攻击 Ce 活性位点。
关键词:CeO 2 ;磷酸化;氨选择性催化还原;碱金属耐受性;氮氧化物;环境保护
中图分类号:X701;TQ426 文献标识码:A 文章编号:1003-5214 (2022) 05-0995-10
Surface phosphorylation of CeO 2 for selective reduction of
NO and its alkali metal tolerance
*
LI Shun, HU Fangfang, WANG Wenzhi, CAI Sixiang , JIANG Hong
(State Key Laboratory of Marine Resources Utilization of the South China Sea, Special Glass Laboratory of Hainan
Province, College of Materials Science and Engineering, Hainan University, Haikou 570228, Hainan, China)
Abstract: Phosphorylated CeO 2 catalysts were firstly prepared by impregnation method using Ce(NO 3 ) 3 •6H 2O
and (NH 4 ) 3 PO 4 •3H 2 O as raw materials, and then its denitration performance over selective catalytic reduction
of NO using NH 3 as reducing agent (NH 3-SCR) was investigated. The structures and properties of catalysts
were characterized by XRD, N 2 adsorption-desorption, XPS, NH 3-TPD and in situ DRIFTS. The results
showed that the NO conversion rate was more than 90% in temperature range 250~500 ℃, and remained
above 80% in the range of 300~400 ℃ even after phosphorylated CeO 2 catalyst was poisoned by alkali
metals and alkaline earth metals. The enhanced catalytic performance of phosphorylated CeO 2 was attributed
to the increase in the number of acid, especially Brønsted acid sites. The phosphorylation modification
3+
produced more Ce and chemisorbed oxygen, which improved the redox capacity of the catalyst. When
deposited on the catalyst, the alkali metals were induced to migrate to the surface of phosphorylated CeO 2
4+
and bound to the Ce—O—P base capture site, being prevented from attacking the Ce active site.
Key words: CeO 2; phosphorylation; NH 3-SCR; alkali metal tolerance; nitrogen oxides; environmental
protection
氮氧化物(NO x )是主要的大气污染物之一, 等一系列问题 [1-2] 。目前,使用氨气作为还原剂选择
会带来诸如光化学烟雾、PM 2.5 、臭氧层破坏、酸雨 性催化还原 NO x (NH 3 -SCR)的技术是应用最广且
收稿日期:2021-11-19; 定用日期:2022-03-20; DOI: 10.13550/j.jxhg.20211128
基金项目:海南省自然科学基金青年基金项目(221QN0859);海南省重点研发计划项目(ZDYF2020015);海南大学科研平台建设
(ZY2019HN09)
作者简介:李 顺(1996—),男,硕士生,E-mail:1208808626@qq.com。联系人:蔡思翔(1991—),男,博士,讲师,硕士生导
师,E-mail:993049@hainanu.edu.cn。