Mo的引入方式对CeO2脱硝性能的影响

doi:10.1016/S1872-2067(20)63778-0

催化学报 ›› 2021, Vol. 42 ›› Issue (9): 1488-1499.DOI: 10.1016/S1872-2067(20)63778-0

Mo的引入方式对CeO₂脱硝性能的影响

李露露^a^,^b^,^d^,^†, 葛成艳^e^,^†, 季稼伟^a, 谭伟^a, 王鑫^a, 魏小倩^a, 郭凯^a, 汤常金^a^,^b^,^f^,^#(), 董林^b^,^c^,^*()

^a南京大学化学化工学院, 江苏南京210093
^b南京大学现代分析中心, 江苏省机动车尾气污染控制重点实验室, 江苏南京210093
^c南京大学环境学院, 江苏南京210093
^d江苏科技大学环境与化学工程学院, 江苏镇江212003
^e盐城工学院化学化工学院, 江苏盐城224051
^f南京师范大学环境学院, 江苏南京210093

收稿日期:2020-11-24 接受日期:2021-01-25 出版日期:2021-09-18 发布日期:2021-05-16
通讯作者: 汤常金,董林
作者简介:第一联系人：
^†共同第一作者.
基金资助:
国家自然科学基金(21806077);国家自然科学基金(21773106);国家自然科学基金(21707066);国家自然科学基金(21607122)

Effects of different methods of introducing Mo on denitration performance and anti-SO₂ poisoning performance of CeO₂

Lulu Li^a^,^b^,^d^,^†, Chengyan Ge^e^,^†, Jiawei Ji^a, Wei Tan^a, Xin Wang^a, Xiaoqian Wei^a, Kai Guo^a, Changjin Tang^a^,^b^,^f^,^#(), Lin Dong^b^,^c^,^*()

^aSchool of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, Jiangsu, China
^bJiangsu Key Laboratory of Vehicle Emissions Control, Center of Modern Analysis, Nanjing University, Nanjing 210093, Jiangsu, China
^cSchool of Environment, Nanjing University, Nanjing 210093, Jiangsu, China
^dSchool of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, Jiangsu, China
^eSchool of Chemistry & Chemical Engineering, Yancheng Institute of Technology, Yancheng 224051, Jiangsu, China
^fSchool of Environment, Nanjing Normal University, Nanjing 210093, Jiangsu, China

Received:2020-11-24 Accepted:2021-01-25 Online:2021-09-18 Published:2021-05-16
Contact: Changjin Tang,Lin Dong
About author:^# E-mail: tangcj@njnu.edu.cn
^* E-mail: donglin@nju.edu.cn;
First author contact:
^†These authors contributed equally to this work.
Supported by:
National Natural Science Foundation of China(21806077);National Natural Science Foundation of China(21773106);National Natural Science Foundation of China(21707066);National Natural Science Foundation of China(21607122)

摘要/Abstract

摘要：

固定源排放的氮氧化物(NO_x)导致了严重的环境污染问题, NH₃选择性催化还原(NH₃-SCR)被认为是目前控制NO_x排放的最有效技术, 已广泛应用于电力行业的烟气排放治理. 然而, 我国非电行业的NO_x减排仍然面临着重大挑战, 因为其排放的废气温度通常低于300 ºC, 且含有一定量的SO₂, 传统的钒基SCR催化剂因活性温度(300~400 ºC)较高而无法有效发挥作用. 因此, 亟待开发新型的高效低温SCR催化剂.
铈基催化剂由于氧化铈(CeO₂)的优异储氧能力(OSC)和良好的氧化还原能力而显示出较好的低温(80~300 ºC)脱硝性能, 如Mn-Ce, W-Ce, Ta-Ce, Cu-Ce和Nb-Ce等. 但这些铈基催化剂易被烟气中的SO₂毒化而导致催化活性降低. 因此, 提高铈基SCR催化剂抗硫中毒能力是其产业化应用的关键. 已有研究发现, 通过构筑结构保护层或添加另一种金属来保护活性组分是提高SCR催化剂抗硫性能的一种可行策略. 氧化钼(MoO₃)通常被用做传统V₂O₅/TiO₂催化剂的促进剂以提高其水热稳定性和表面酸性. 研究表明, 在V/Ti催化剂中引入钼物种不仅可以提高其SCR活性, 而且提高了V/Ti催化剂的抗SO₂性能, 这是由于VMo/Ti表面较少的V‒O‒V键削弱了对SO₂的氧化作用. Tang等开发了一种Fe₂O₃/MoO₃纳米片催化剂, 显示出比纯Fe₂O₃更好的抗SO₂能力, 主要是由于层状结构的MoO₃能阻止NH₄⁺在硫酸氢铵中的沉积. 目前关于Mo的引入方式即催化剂的制备方法对铈基催化剂物化性能和NH₃-SCR催化性能(特别是抗SO₂能力)的影响的研究还比较少.
本文分别采用浸渍法和沉淀法在CeO₂中引入钼物种, 制备了Mo-CeO₂和MoCe-cp催化剂来探究制备方法对MoCe催化剂的脱硝性能及抗SO₂中毒能力的影响. 结果表明, 引入Mo可以显著地提高CeO₂的低温脱硝性能, 其中Mo-CeO₂催化剂在150°C即可达到80%以上的脱硝效率, 同时抗SO₂中毒性能也得到了显著提高. 对催化剂结构、氧化还原能力、表面酸度和反应物分子的吸附脱附性质进行了表征, 并与MoCe催化剂脱硝性能和抗硫性能相关联. 结果表明, Mo-CeO₂和MoCe-cp催化剂的物理化学性质和脱硝性能有明显区别. 首先, Mo-CeO₂中的钼物种主要存在于CeO₂表面, 而MoCe-cp中的钼物种主要存在于CeO₂体相, 其为Mo-CeO₂表面带来大量的Brönsted酸位并抑制了硝酸盐的吸附, 促使NH₃-SCR反应按照Eley-Rideal机理进行, 进而表现出优于MoCe-cp的低温活性. 其次, Mo-CeO₂表面更多的Mo物种抑制了SO₂的吸附, 从而使Mo-CeO₂表现出更好的抗SO₂性能. 本文为具有实际应用前景的铈基NH₃-SCR催化剂的设计提供了参考.

关键词: 表面修饰, MoO₃-CeO₂, 氨选择催化还原, Br?nsted酸位, 抗SO₂中毒

Abstract:

Cerium-based catalysts are very attractive for the catalytic abatement of nitrogen oxides (NO_x) emitted from stationary sources. However, the main challenge is still achieving satisfactory catalytic activity in the low-temperature range and tolerance to SO₂ poisoning. In the present work, two series of Mo-modified CeO₂ catalysts were respectively obtained through a wet impregnation method (Mo-CeO₂) and a co-precipitation method (MoCe-cp), and the roles of the Mo species were systematically investigated. Activity tests showed that the Mo-CeO₂ catalyst displayed much higher NO conversion at low temperature and anti-SO₂ ability than MoCe-cp. The optimal Mo-CeO₂ catalyst displayed over 80% NO elimination efficiency even at 150 °C and remarkable SO₂ resistance at 250 °C (nearly no activity loss after 40 h test). The characterization results indicated that the introduced Mo species were highly dispersed on the Mo-CeO₂ catalyst surface, thereby providing more Brønsted acid sites and inhibiting the formation of stable adsorbed NO_x species. These factors synergistically promote the selective catalytic reduction (SCR) reaction in accordance with the Eley-Rideal (E-R) reaction path on the Mo-CeO₂ catalyst. Additionally, the molybdenum surface could protect CeO₂ from SO₂poisoning; thus, the reducibility of the Mo-CeO₂ catalyst declined slightly to an adequate level after sulfation. The results in this work indicate that surface modification with Mo species may be a simple method of developing highly efficient cerium-based SCR catalysts with superior SO₂ durability.

Key words: Surface modification, MoO₃-CeO₂, NH₃-SCR, Br?nsted acid sites, SO₂ resistance

李露露, 葛成艳, 季稼伟, 谭伟, 王鑫, 魏小倩, 郭凯, 汤常金, 董林. Mo的引入方式对CeO₂脱硝性能的影响[J]. 催化学报, 2021, 42(9): 1488-1499.

Lulu Li, Chengyan Ge, Jiawei Ji, Wei Tan, Xin Wang, Xiaoqian Wei, Kai Guo, Changjin Tang, Lin Dong. Effects of different methods of introducing Mo on denitration performance and anti-SO₂ poisoning performance of CeO₂[J]. Chinese Journal of Catalysis, 2021, 42(9): 1488-1499.

×
扫码分享

导出引用管理器 EndNote|Ris|BibTeX

链接本文: https://www.cjcatal.com/CN/10.1016/S1872-2067(20)63778-0

https://www.cjcatal.com/CN/Y2021/V42/I9/1488

图/表 16

Fig. 1. The NO conversions of the synthesized catalysts.

Fig. 2. The H2O and SO2 durability of these catalysts at 250 °C. (a) SO2 durability over Mo-CeO2, MoCe-cp and CeO2 catalysts; (b) H2O+SO2 durability over Mo-CeO2 and MoCe-cp.

Fig. 3. The XRD (a) and Raman (b) patterns of these synthesized catalysts.

Fig. 4. The TEM images of CeO2 (a), Mo-CeO2 (b), and MoCe-cp (c); the HRTEM images of CeO2 (d), Mo-CeO2 (e), and MoCe-cp (f).

Table 1 The results of BET, pore diameter and the peak area of NH3-TPD curves and NOx-TPD curves over these samples.

Sample	S_BET (m²·g^‒1)	Pore diameter (nm)	peak area of NH₃-TPD curves/a.u.	peak area of NO_x-TPD curves/a.u.
CeO₂	88.1	2.9	—	—
Mo-CeO₂	66.4	8.7	5711	9641
MoCe-cp	119.6	8.9	6219	28130

Fig. 5. N2 adsorption-desorption isotherms (a) and BJH pore distribution curves (b) of these catalysts.

Fig. 6. XPS results of these synthesized catalysts. (a) Mo 3d; (b) S 2p; (c) Ce 3d; (d,e) O 1s.

Table 2 The fitting data of XPS over these samples.

Sample	Ce³⁺/ (Ce³⁺+Ce⁴⁺)/%	O_α/ (O_α+O_β)/%	Atomic concentration of Mo	Atomic concentration of S
CeO₂	17	22	—	—
Mo-CeO₂	18	12	3.42	—
MoCe-cp	22	28	0.49	—
CeO₂-U	38	47	—	3.07
Mo-CeO₂-U	22	29	3.04	1.65
MoCe-cp-U	33	48	0.49	2.71

Fig. 7. H2-TPR results of different catalysts.

Fig. 8. NH3-TPD (a) and NOx-TPD (b) results of different catalysts.

Fig. 9. NH3 adsorption in situ DRIFTS of the Mo-CeO2 (a) and MoCe-cp (b) catalysts at 150 °C.

Fig. 10. NO+O2 adsorption in situ DRIFTS of the Mo-CeO2 (a) and MoCe-cp (b) catalysts at 150 °C.

Fig. 11. NO+O2 adsorption in situ DRIFTS of Mo-CeO2 (a) and MoCe-cp (b) pre-adsorbed NH3 at 150 °C.

Fig. 12. NH3 adsorption in situ DRIFTS of Mo-CeO2 (a) and MoCe-cp (b) pre-adsorbed NO+O2 at 150 °C.

Fig. 13. TG curves of CeO2-U, Mo-CeO2-U and MoCe-cp-U catalysts.

Fig. 14. SO2+O2 adsorption in situ DRIFTS of CeO2 (a), Mo-CeO2 (b) and MoCe-cp (c) catalysts at 250 °C.

参考文献

[1]	J. K. Lai, I. E. Wachs, ACS Catal., 2018,8, 6537-6551.
[2]	T. Xu, X. Wu, Y. Gao, Q. Lin, J. Hu, D. Weng, Catal. Commun., 2017,93, 33-36.
[3]	S. Zhang, S. Liu, W. Hu, X. Zhu, R. Qu, C. Zheng, X. Gao, Appl. Surf. Sci., 2019,466, 99-109.
[4]	K. Zha, S. Cai, H. Hu, H. Li, L. Shi, D. Zhang, J. Phys. Chem. C, 2017,121, 25243-25254.
[5]	F. Eigenmann, M. Maciejewski, A. Baiker, Appl. Catal. B, 2006,62, 311-318.
[6]	W. Shan, F. Liu, H. He, X. Shi, C. Zhang, Chem. Commun., 2011,47, 8046-8048.
[7]	T. Zhang, R. Qu, W. Su, J. Li, Appl. Catal. B, 2015, 176-177, 338-346.
[8]	M. Xing, Q. Sun, C. Zeng, D. Zhao, N. Zhang, S. Hong, RSC Adv., 2017,7, 18830-18837.
[9]	R. Qu, X. Gao, K. Cen, J. Li, Appl. Catal. B, 2013, 142-143, 290-297.
[10]	L. Han, M. Gao, J. Y. Hasegawa, S. Li, Y. Shen, H. Li, L. Shi, D. Zhang, Environ. Sci. Technol., 2019,53, 6462-6473.
[11]	Y. Zhang, G. Li, P. Wu, K. Shen, S. Wang, T. Huang, Chem. Eng. J., 2020,400, 122597.
[12]	Y. Qiu, B. Liu, J. Du, Q. Tang, Z. Liu, R. Liu, C. Tao, Chem. Eng. J., 2016,294, 264-272.
[13]	H. Li, J. Wan, Y. Ma, Y. Wang, Chem. Eng. J., 2016, 315-324
[14]	Y. Chen, C. Li, J. Chen, X. Tang, Environ. Sci. Technol., 2018,52, 11796-11802.
[15]	L. Zhang, L. Li, Y. Cao, C. Ge, F. Gao, Y. Deng, C. Tang, L. Dong, Appl. Catal. B, 2015,165, 589-598.
[16]	X. Yao, L. Chen, F. Yang, W. Tan, L. Dong, Ind. Eng. Chem. Res., 2018,57, 12407-12419.
[17]	W. Yu, J. Zhu, L. Qi, C. Sun, F. Gao, L. Dong, Y. Chen, J. Colloid Interface Sci., 2011,364, 435-442.
[18]	J. Zhu, F. Gao, L. Dong, W. Yu, L. Qi, Z. Wang, L. Dong, Y. Chen, Appl. Catal. B, 2010,95, 144-152.
[19]	Z. Sheng, D. Ma, D. Yu, X. Xiao, B. Huang, L. Yang, S. Wang, Chin. J. Catal., 2018,39, 821-830.
[20]	Z. Fei, Y. Yang, M. Wang, Z. Tao, Q. Liu, X. Chen, M. Cui, Z. Zhang, J. Tang, X. Qiao, Chem. Eng. J., 2018,353, 930-939.
[21]	L. Kang, L. Han, J. He, H. Li, T. Yan, G. Chen, J. Zhang, L. Shi, D. Zhang, Environ. Sci. Technol., 2019,53, 938-945.
[22]	Y. Peng, R. Qu, X. Zhang, J. Li, Chem. Commun., 2013,49, 6215-6217.
[23]	Z. Huang, Y. Du, J. Zhang, X. Wu, H. Shen, G. Jing, Environ. Sci. Technol., 2019,53, 5309-5318.
[24]	X. Hu, Q. Shi, H. Zhang, P. Wang, S. Zhan, Y. Li, Catal. Today, 2017,297, 17-26.
[25]	C. Sun, H. Liu, W. Chen, S. Yu, A. Liu, L. Dong, S. Feng, Chem. Eng. J., 2018,347, 27-40.
[26]	B. Shen, X. Zhang, H. Ma, Y. Yao, T. Liu, J. Environ. Sci., 2013,25, 791-800.
[27]	Y. Zeng, W. Song, Y. Wang, S. Zhang, T. Wang, Q. Zhong, J. Hazard. Mater., 2020,383, 121212.
[28]	H. Liu, Z. Fan, C. Sun, S. Yu, S. Feng, W. Chen, D. Chen, C. Tang, F. Gao, L. Dong, Appl. Catal. B, 2019,244, 671-683.
[29]	L. Zhang, W. Zou, K. Ma, Y. Cao, Y. Xiong, S. Wu, C. Tang, F. Gao, L. Dong, J. Phys. Chem. C, 2015,119, 1155-1163.
[30]	L. Zhang, L. Li, C. Ge, T. Li, C. Li, S. Li, F. Xiong, L. Dong, Ind. Eng. Chem. Res., 2019,58, 6325-6332.
[31]	Y. Peng, R. Y. Qu, X. Y. Zhang, J. Li, Chem. Commun., 2013,49, 6215-6217
[32]	X. Wang, Z. Rui, H. Ji, Catal. Today, 2020,347, 124-133.
[33]	L. Yan, Y. Liu, K. Zha, H. Li, L. Shi, D. Zhang, Catal. Sci. Technol., 2017,7, 502-514.
[34]	H. Chang, J. Li, X. Chen, S. Yang, J. W. Schwank, J. Hao, Catal. Commun., 2012,27, 54-57.
[35]	Y. Xiong, C. Tang, X. Yao, L. Zhang, L. Li, X. Wang, Y. Deng, F. Gao, L. Dong, Appl. Catal. A, 2015,495, 206-216.
[36]	M. Chen, Q. Jin, X. Tao, Y. Pan, Y. Shen, Catal. Today, 2019,319, 254-262
[37]	Z. Y. Wang, R. T. Guo, X. Shi, X. Liu, H. Qin, Y. Liu, C. P. Duan, D. Y. Guo, W. G. Pan, Chem. Eng. J., 2020,381, 122753.
[38]	X. Li, X. Li, J. Li, J. Hao, J. Hazard. Mater., 2016,318, 615-622.
[39]	Y. Geng, X. Chen, S. Yang, F. Liu, W. Shan, ACS Appl. Mater. Intefaces, 2017,9, 16951-16958.
[40]	Z. Liu, H. Su, J. Li, Y. Li, Catal. Commun., 2015,65, 51-54.
[41]	L. Li, W. Tan, X. Wei, Z. Fan, A. Liu, K. Guo, K. Ma, S. Yu, C. Ge, C. Tang, L. Dong, Catal. Commun., 2018,114, 10-14.
[42]	S. Cai, D. Zhang, L. Zhang, L. Huang, H. Li, R. Gao, L. Shi, J. Zhang, Catal. Sci. Technol., 2014,4, 93-101.
[43]	M. Qiu, S. Zhan, H. Yu, D. Zhu, S. Wang, Nanoscale, 2015,7, 2568-2577.
[44]	P. Fabrizioli, T. Bürgi, A. Baiker, J. Catal., 2002,206, 143-154.
[45]	T. Gu, R. Jin, Y. Liu, H. Liu, X. Weng, Z. Wu, Appl. Catal. B, 2013,129, 30-38.
[46]	T. Gu, Y. Liu, X. Weng, H. Wang, Z. Wu, Catal. Commun., 2010,12, 310-313.
[47]	T. H. Vuong, J. Radnik, J. Rabeah, U. Bentrup, M. Schneider, H. Atia, U. Armbruster, W. Grünert, A. Brückner, ACS Catal., 2017,7, 1693-1705.
[48]	L. Li, L. Zhang, K. Ma, W. Zou, Y. Cao, Y. Xiong, C. Tang, L. Dong, Appl. Catal. B, 2017,207, 366-375.
[49]	D. Meng, W. Zhan, Y. Guo, Y. Guo, L. Wang, G. Lu, ACS Catal., 2015,5, 5973-5983.
[50]	X. Wang, Y. Shi, S. Li, W. Li, Appl. Catal. B, 2018,220, 234-250.
[51]	L. Zhang, L. Li, Y. Cao, Y. Xiong, S. Wu, J. Sun, C. Tang, F. Gao, L. Dong, Catal. Sci. Technol., 2015,5, 2188-2196.
[52]	K. Guo, Y. X. Zhu, Z. Yan, A. Liu, X. Wang, W. Tan, L. Li, J. Sun, Q. Tong, C. Tang, L. Dong, Chem. Eng. J., 2020,389, 124271.
[53]	Z. Y. Wang, R. T. Guo, X. Shi, W. G. Pan, J. Hazard. Mater., 2020,381, 12253.
[54]	S. Yang, Y. Guo, H. Chang, L. Ma, Y. Peng, Z. Qu, N. Yan, C. Wang, J. Li, Appl. Catal. B, 2013, 136-137, 19-28.
[55]	X. X. Wang, Q. Cong, L. Chen, Y. Shi, S. J. Li, W. Li, Appl. Catal. B, 2019,246, 166-179
[56]	Z. P. Zhang, R. M. Li, M. J. Wang, Y. Li, Y. Tong, P. P. Yang, Y. J. Zhu, Appl. Catal. B, 2021,282, 119542.

Mo的引入方式对CeO₂脱硝性能的影响

Effects of different methods of introducing Mo on denitration performance and anti-SO₂ poisoning performance of CeO₂

RichHTML

PDF

可视化

摘要/Abstract

引用本文

使用本文

扫码分享

图/表 16

参考文献

相关文章 15

编辑推荐

Metrics

[1]	龚隽, 李金梦, 刘畅, 魏丰源, 殷金龙, 李文正, 肖丽, 王功伟, 陆君涛, 庄林. 鸟嘌呤调控质子转移促进铜电催化CO₂还原选择制甲烷[J]. 催化学报, 2022, 43(12): 3101-3106.
[2]	李佳原, 朱勇, 李斐, 刘国权, 许素显, 孙立成. 修饰吡啶衍生物的染料敏化光阳极水氧化性能的研究[J]. 催化学报, 2021, 42(8): 1352-1359.
[3]	张祥勇, 刘添滢, 郭挺, 韩雪莹, 木宗云, 陈强, 蒋江民, 闫婧, 袁加仁, 王德志, 吴壮志, 寇宗魁. 可控表面磷原子修饰提升超细W₂C纳米颗粒电解水析氢反应性能[J]. 催化学报, 2021, 42(10): 1798-1807.
[4]	李露露, 李佩晓, 谭伟, 马凯莉, 邹伟欣, 汤常金, 董林. 表面Mo修饰提高CeTiO_x催化剂低温脱硝性能[J]. 催化学报, 2020, 41(2): 364-373.
[5]	黎小芳, 伍晓锋, 刘升卫, 李宇涵, 范佳杰, 吕康乐. 光催化的氟效应[J]. 催化学报, 2020, 41(10): 1451-1467.
[6]	王蘅, 胡仙桃, 马亚娟, 朱大建, 李涛, 王靖宇. 硝酸根接枝诱导组装金红石相TiO₂纳米束以增强光催化产氢[J]. 催化学报, 2020, 41(1): 95-102.
[7]	刘梦, 石松, 赵丽, 陈晨, 高进, 徐杰. 脂肪胺修饰的CoO纳米粒子催化分子氧选择氧化芳香烃[J]. 催化学报, 2019, 40(10): 1488-1493.
[8]	蒋华麟, 刘军, 厉梦琳, 田磊, 丁攻圣, 陈萍华, 罗旭彪. 通过一种新型共前驱体的方法简单合成能增强TiO₂可见光光催化活性的C修饰及Fe,N共掺杂的TiO₂材料[J]. 催化学报, 2018, 39(4): 747-759.
[9]	郑龙辉, 于晓娟, 龙明策, 李琪琳. 磷酸根和Nafion修饰TiO₂表面腐植酸调控的可见光催化降解苯酚性能[J]. 催化学报, 2017, 38(12): 2076-2084.
[10]	李昱琳, 韩小金, 侯亚芹, 郭耀萍, 刘勇进, 向宁, 崔燕, 黄张根. F127辅助制备介孔Fe/TiO₂催化剂用于中温NH₃选择性催化还原反应[J]. 催化学报, 2017, 38(11): 1831-1841.
[11]	龙雨, 袁冰, 马建泰 . 埃洛石表面修饰并负载salen钼高效催化烯烃环氧化反应[J]. 催化学报, 2015, 36(3): 348-354.
[12]	李轩, 叶霜, 赵建波, 李磊, 彭路明, 丁维平. 表面修饰的钒氧化物纳米带上甲苯选择氧化反应[J]. 催化学报, 2013, 34(7): 1297-1302.
[13]	彭定芬;余皓;彭峰;王红娟;杨剑. 碳纳米管表面羧基对纳米 RuO2 颗粒的分散作用[J]. 催化学报, 2009, 30(6): 570-576.
[14]	贾永涛;王闯;梁长海;邱介山;. CNT表面修饰对Pt/CNT在邻氯硝基苯加氢反应中催化性能的影响[J]. 催化学报, 2009, 30(10): 1029-1034.
[15]	王林芳;马磊;王爱琴;刘茜;张涛. 氨基硅烷修饰的SBA-15用于CO2的吸附[J]. 催化学报, 2007, 28(9): 805-810.