Citation: Zeng Jin-Long, Xiong Zhi-Tao, Lin Guo-Dong, Yu La-Jia, Zhang Hong-Bin. Spectroscopic Characterization of Mo/HZSM-5-based Catalysts for Dehydro-aromatization of Methane[J]. Acta Physico-Chimica Sinica, ;1998, 14(05): 394-400. doi: 10.3866/PKU.WHXB19980503
-
By using H2-TPR, XPS, and EPR spectroscopic methods, the reducibility of theMo/HZSM-5 based catalysts and valence-states of the Mthspecies on/in the functioning catalysts were investigated. The results of H2-TPR showed that the proportion of the Mo-species reducible to lower valence state(s) in the catalyst prepared at high calcination temperature (973K) was pronouncedly decreased, most probably due to aggregation of the Mo-species and formation ofMoO3 crystallites. XPS measurement on the acid-promoted Mo-ZnSO4/HZSM-5 catalyst indicated that there existed Mo-species with mixed valence-states at the surface of the functioning catalyst, with Mo4+ in major (ca. 85mol%) and Mo5+ in minor (ca. 15mol%) in quantities. A strong EPR signal (g|| =1.88, g⊥=1.93 ) assignable to Mo5+ appeared in the EPR spectrum taken on the Mo/HZSM-5 catalyst prepared at the calcination temperature of 973K; whereas the intensity of this signal was pronouncedly decreased for both MthZnSO4/HZSM-5 and Mo/HZSM-5 catalysts prepared at the calcination temperature of 673K- The results of the present work indicate the absence of proportional correlation between high activity of methane conversion over the strong acid-promoted Mo/HZSM-5-based catalysts and the concentration of Mo5-sites at the surface of functioning catalysts, and are in favor of the following viewpoints, i.e., the crucial first step of activation-dehydrogenation of methane was more likely to be mainly via the pathway of B-acid-assisted dehydrogenation by heterolytic splitting of C-H bond, whereas the lower valence Mo-species (mainly Mo4+) may play a key role in the stabilization of metal-carbene intermediates and in the sequent aromatization.
-
-
[1]
Yunhao Zhang , Yinuo Wang , Siran Wang , Dazhen Xu . Progress in Selective Construction of Functional Aromatics from Nitrogenous Cycloalkanes. University Chemistry, 2024, 39(11): 136-145. doi: 10.3866/PKU.DXHX202401083
-
[2]
Wen YANG , Didi WANG , Ziyi HUANG , Yaping ZHOU , Yanyan FENG . La promoted hydrotalcite derived Ni-based catalysts: In situ preparation and CO2 methanation performance. Chinese Journal of Inorganic Chemistry, 2024, 40(3): 561-570. doi: 10.11862/CJIC.20230276
-
[3]
Yinuo Wang , Siran Wang , Yilong Zhao , Dazhen Xu . Selective Synthesis of Diarylmethyl Anilines and Triarylmethanes via Multicomponent Reactions: Introduce a Comprehensive Experiment of Organic Chemistry. University Chemistry, 2024, 39(8): 324-330. doi: 10.3866/PKU.DXHX202401063
-
[4]
Zhiquan Zhang , Baker Rhimi , Zheyang Liu , Min Zhou , Guowei Deng , Wei Wei , Liang Mao , Huaming Li , Zhifeng Jiang . Insights into the Development of Copper-based Photocatalysts for CO2 Conversion. Acta Physico-Chimica Sinica, 2024, 40(12): 2406029-. doi: 10.3866/PKU.WHXB202406029
-
[5]
Caixia Lin , Zhaojiang Shi , Yi Yu , Jianfeng Yan , Keyin Ye , Yaofeng Yuan . Ideological and Political Design for the Electrochemical Synthesis of Benzoxathiazine Dioxide Experiment. University Chemistry, 2024, 39(2): 61-66. doi: 10.3866/PKU.DXHX202309005
-
[6]
Jingyu Cai , Xiaoyu Miao , Yulai Zhao , Longqiang Xiao . Exploratory Teaching Experiment Design of FeOOH-RGO Aerogel for Photocatalytic Benzene to Phenol. University Chemistry, 2024, 39(4): 169-177. doi: 10.3866/PKU.DXHX202311028
-
[7]
Yingchun ZHANG , Yiwei SHI , Ruijie YANG , Xin WANG , Zhiguo SONG , Min WANG . Dual ligands manganese complexes based on benzene sulfonic acid and 2, 2′-bipyridine: Structure and catalytic properties and mechanism in Mannich reaction. Chinese Journal of Inorganic Chemistry, 2024, 40(8): 1501-1510. doi: 10.11862/CJIC.20240078
-
[8]
Tao Cao , Fang Fang , Nianguang Li , Yinan Zhang , Qichen Zhan . Green Synthesis of p-Hydroxybenzonitrile Catalyzed by Spinach Extracts under Red-Light Irradiation: Research and Exploration of Innovative Experiments for Pharmacy Undergraduates. University Chemistry, 2024, 39(5): 63-69. doi: 10.3866/PKU.DXHX202309098
-
[9]
Zhanggui DUAN , Yi PEI , Shanshan ZHENG , Zhaoyang WANG , Yongguang WANG , Junjie WANG , Yang HU , Chunxin LÜ , Wei ZHONG . Preparation of UiO-66-NH2 supported copper catalyst and its catalytic activity on alcohol oxidation. Chinese Journal of Inorganic Chemistry, 2024, 40(3): 496-506. doi: 10.11862/CJIC.20230317
-
[10]
Qingqing SHEN , Xiangbowen DU , Kaicheng QIAN , Zhikang JIN , Zheng FANG , Tong WEI , Renhong LI . Self-supporting Cu/α-FeOOH/foam nickel composite catalyst for efficient hydrogen production by coupling methanol oxidation and water electrolysis. Chinese Journal of Inorganic Chemistry, 2024, 40(10): 1953-1964. doi: 10.11862/CJIC.20240028
-
[11]
Qiangqiang SUN , Pengcheng ZHAO , Ruoyu WU , Baoyue CAO . Multistage microporous bifunctional catalyst constructed by P-doped nickel-based sulfide ultra-thin nanosheets for energy-efficient hydrogen production from water electrolysis. Chinese Journal of Inorganic Chemistry, 2024, 40(6): 1151-1161. doi: 10.11862/CJIC.20230454
-
[12]
Yingxian Wang , Tianye Su , Limiao Shen , Jinping Gao , Qinghe Wu . Introduction of Chinese Lacquer from the Perspective of Chemistry: Popularizing Chemistry in Lacquer and Inherit Lacquer Art. University Chemistry, 2024, 39(5): 371-379. doi: 10.3866/PKU.DXHX202312015
-
[13]
Liyang ZHANG , Dongdong YANG , Ning LI , Yuanyu YANG , Qi MA . Crystal structures, luminescent properties and Hirshfeld surface analyses of three cadmium(Ⅱ) complexes based on 2-(3-(pyridin-2-yl)-1H-pyrazol-1-yl)benzoate. Chinese Journal of Inorganic Chemistry, 2024, 40(10): 1943-1952. doi: 10.11862/CJIC.20240079
-
[14]
Kaihui Huang , Dejun Chen , Xin Zhang , Rongchen Shen , Peng Zhang , Difa Xu , Xin Li . Constructing Covalent Triazine Frameworks/N-Doped Carbon-Coated Cu2O S-Scheme Heterojunctions for Boosting Photocatalytic Hydrogen Production. Acta Physico-Chimica Sinica, 2024, 40(12): 2407020-. doi: 10.3866/PKU.WHXB202407020
-
[15]
Jinyao Du , Xingchao Zang , Ningning Xu , Yongjun Liu , Weisi Guo . Electrochemical Thiocyanation of 4-Bromoethylbenzene. University Chemistry, 2024, 39(6): 312-317. doi: 10.3866/PKU.DXHX202310039
-
[16]
Yuanyin Cui , Jinfeng Zhang , Hailiang Chu , Lixian Sun , Kai Dai . Rational Design of Bismuth Based Photocatalysts for Solar Energy Conversion. Acta Physico-Chimica Sinica, 2024, 40(12): 2405016-. doi: 10.3866/PKU.WHXB202405016
-
[17]
Dan Li , Hui Xin , Xiaofeng Yi . Comprehensive Experimental Design on Ni-based Catalyst for Biofuel Production. University Chemistry, 2024, 39(8): 204-211. doi: 10.3866/PKU.DXHX202312046
-
[18]
Juntao Yan , Liang Wei . 2D S-Scheme Heterojunction Photocatalyst. Acta Physico-Chimica Sinica, 2024, 40(10): 2312024-. doi: 10.3866/PKU.WHXB202312024
-
[19]
Ling Liu , Haibin Wang , Genrong Qiang . Curriculum Ideological and Political Design for the Comprehensive Preparation Experiment of Ethyl Benzoate Synthesized from Benzyl Alcohol. University Chemistry, 2024, 39(2): 94-98. doi: 10.3866/PKU.DXHX202304080
-
[20]
Feng Sha , Xinyan Wu , Ping Hu , Wenqing Zhang , Xiaoyang Luan , Yunfei Ma . Design of Course Ideology and Politics for the Comprehensive Organic Synthesis Experiment of Benzocaine. University Chemistry, 2024, 39(2): 110-115. doi: 10.3866/PKU.DXHX202307082
-
[1]
Metrics
- PDF Downloads(2191)
- Abstract views(4161)
- HTML views(20)