Volume 8 Issue 2
Apr.  2023
Turn off MathJax
Article Contents
Article Navigation >  Green Energy&Environment  > 2023  >  8(2): 487-498
Chenyang Li, Yuan Zhang, Debao Li, Baojun Wang, Christopher K. Russell, Maohong Fan, Riguang Zhang. The newly-assisted catalytic mechanism of surface hydroxyl species performed as the promoter in syngas-to-C2 species on the Cu-based bimetallic catalysts. Green Energy&Environment, 2023, 8(2): 487-498. doi: 10.1016/j.gee.2021.06.001
Citation: Chenyang Li, Yuan Zhang, Debao Li, Baojun Wang, Christopher K. Russell, Maohong Fan, Riguang Zhang. The newly-assisted catalytic mechanism of surface hydroxyl species performed as the promoter in syngas-to-C2 species on the Cu-based bimetallic catalysts. Green Energy&Environment, 2023, 8(2): 487-498. doi: 10.1016/j.gee.2021.06.001
shu

The newly-assisted catalytic mechanism of surface hydroxyl species performed as the promoter in syngas-to-C2 species on the Cu-based bimetallic catalysts

doi: 10.1016/j.gee.2021.06.001

  • a. State Key Laboratory of Clean and Efficient Coal Utilization, Taiyuan University of Technology, Taiyuan, Shanxi, 030024, China;

  • b. Key Laboratory of Coal Science and Technology (Taiyuan University of Technology), Ministry of Education, China;

  • c. State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi, 030001, China;

  • d. College of Engineering and Applied Science, University of Wyoming, Laramie, WY, 82071, USA;

  • e. Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, 47906, USA;

  • f. School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA;

  • g. School of Energy Resources, University of Wyoming, Laramie, WY, 82071, USA

Funds:

This work is financially supported by Key Projects of National Natural Science Foundation of China (No. 21736007), National Natural Science Foundation of China (Nos. 22078221, 21776193, 21476155) and Top Young Innovative Talents of Shanxi.

  • Received date 26 December 2020, Accepted date 13 June 2021, RevRecd date 05 June 2021, Publish date 15 June 2021,
    Abstract
  • In the conversion process of syngas-to-C2 species, the OH species are inevitably produced accompanying the production of key intermediates CHx(x = 1–3), traditionally , the function of surface OH species is generally accepted as the hydrogenating reactive species. This work for the first time proposed and confirmed the assisted catalytic mechanism of surface OH species that performed as the promoter for syngas-to-C2 species on Cu-based catalysts. DFT and microkinetic modeling results reveal that the produced OH species accompanying the intermediates CHx production on the MCu (M = Co, Fe, Rh) catalysts can stably exist to form OH/MCu catalysts, on which the presence of surface OH species as the promoter not only presented better activity and selectivity toward CHx(x = 1–3) compared to MCu catalysts, but also significantly suppressed CH3OH production, providing enough CH sources to favor the production of C2 hydrocarbons and oxygenates. Correspondingly, the electronic properties analysis revealed the essential relationship between the electronic feature of OH/MCu catalysts and catalytic performance, attributing to the unique electronic micro-environment of the catalysts under the interaction of surface OH species. This new mechanism is called as OH-assisted catalytic mechanism, which may be applied in the reaction systems related to the generation of OH species.

     

    • • A newly-assisted function of surface OH as the promoter in syngas conversion on Cu-based catalysts is proposed and confirmed. • The produced surface OH along with CH production on Cu-based catalysts can stably exist to form OH/MCu catalysts. • The surface OH acted as the promoter presented better activity and selectivity toward CH (x = 1–3) and C2 species. • The surface OH acted as the promoter significantly suppressed the selectivity and productivity of CH3OH. • The unique electronic micro-environment of OH/MCu catalysts tunes their catalytic performance.
    Represents co-first authors, and contributed equally to this work.
    FullText(HTML)
  • loading
    • References(86)
  • [1]
    S.C. Chuang, J.G. Goodwin, I. Wender, J. Catal. 95 (1985) 435-446.
    [2]
    X.L. Pan, Z.L. Fan, W. Chen, Y.J. Ding, H.Y. Luo, X.H. Bao, Enhanced ethanol production inside carbon-nanotube reactors containing catalytic particles, Nat. Mater. 6 (2007) 507-511.
    [3]
    L.S. Zhong, F. Yu, Y.L. An, Y.H. Zhao, Y.H. Sun, Z.J. Li, T.J. Lin, Y.J. Lin, X.Z. Qi, Y.Y. Dai, L. Gu, J.S. Hu, S.F. Jin, Q. Shen, H. Wang, Cobalt carbide nanoprisms for direct production of lower olefins from syngas, Nature 538 (2016) 84-87.
    [4]
    X.H. Mo, Y.T. Tsai, J. Gao, D.S. Mao, J.G. Goodwin, Effect of component interaction on the activity of Co/CuZnO for CO hydrogenation, J. Catal. 285 (2012) 208-215.
    [5]
    Y. Chen, H.T. Zhang, H.F. Ma, W.X. Qian, F.Y. Jin, W.Y. Ying, Catal. Lett. 148 (2018) 691-698.
    [6]
    L.P. Han, D.S. Mao, J. Yu, Q.S. Guo, G.Z. Lu, Commun. 23 (2012) 20-24.
    [7]
    N. Kapur, J. Hyun, B. Shan, J.B. Nicholas, K. Cho, Ab initio study of CO hydrogenation to oxygenates on reduced Rh terraces and stepped surfaces, J. Phys. Chem. C 114 (2010) 10171-10182.
    [8]
    S.S.C. Chuang, R.W. Stevens, R. Khatri, Top Catal. 32 (2005) 225-232.
    [9]
    D.H. Mei, R. Rousseau, S.M. Kathmann, V.A. Glezakou, M.H. Engelhard, W.L. Jiang, C.M. Wang, M.A. Gerber, J.F. White, D.J. Stevens, J. Catal. 271 (2010) 325-342.
    [10]
    S. Zaman, K.J. Smith, A review of molybdenum catalysts for synthesis gas conversion to alcohols: Catalysts, mechanisms and kinetics, Catal. Rev. 54 (2012) 41-132.
    [11]
    M. Konarova, F.Q. Tang, J.L. Chen, G. Wang, V. Rudolph, J. Beltramini, Nano-and microscale engineering of the molybdenum disulfide-based catalysts for syngas to ethanol conversion, ChemCatChem 6 (2014) 2394-2402.
    [12]
    M. Ao, G.H. Phama, V. Sage, V. Pareek, Fuel 206 (2017) 390-400.
    [13]
    M.Y. Ding, J.L. Tu, M.H. Qiu, T.J. Wang, L.L. Ma, Y.P. Li, Impact of potassium promoter on Cu-Fe based mixed alcohols synthesis catalyst, Appl. Energ. 138 (2015) 584-589.
    [14]
    X.M. Yang, Y. Wei, Y.L. Su, L.P. Zhou, Characterization of fused Fe-Cu based catalyst for higher alcohols synthesis and DRIFTS investigation of TPSR, Fuel Process. Technol. 91 (2010) 1168-1173.
    [15]
    A.Y. Khodakov, W. Chu, P. Fongarland, Advances in the development of novel cobalt Fischer-Tropsch catalysts for synthesis of long-chain hydrocarbons and clean fuels, Chem. Rev. 107 (2007) 1692-1744.
    [16]
    J. Yoshihara, S.C. Parker, A. Schafer, C.T. Campbell, Methanol synthesis and reverse water-gas shift kinetics over clean polycrystalline copper, Catal. Lett. 31 (1995) 313-324.
    [17]
    C.C. Si, H.Y. Ban, K. Chen, X.Y. Wang, R.W. Cao, Q. Yi, Z.F. Qin, L.J. Shi, Z. Li, W.J. Cai, C.M. Li, Appl. Catal. A-Gen. 594 (2020) 117466.
    [18]
    J.L. Gong, H.R. Yue, Y.J. Zhao, S. Zhao, L. Zhao, J. Lv, S.P. Wang, X.B. Ma, J. Am. Chem. Soc. 134 (2012) 13922-13925.
    [19]
    Q.L. Yang, A. Cao, N. Kang, H.Y. Ning, J.M. Wang, Z.T. Liu, Y. Liu, Bimetallic nano Cu-Co based catalyst for direct ethanol synthesis from syngas and its structure variation with reaction time in slurry reactor, Ind. Eng. Chem. Res. 56 (2017) 2889-2898.
    [20]
    M. Behrens, F. Studt, I. Kasatkin, S. Kuhl, M. Havecker, F. Abild-Pedersen, S. Zander, F. Girgsdies, P. Kurr, B.L. Kniep, M. Tovar, R.W. Fischer, J.K. Noerskov, R. Schlogl, Science 336 (2012) 893-897.
    [21]
    X.C. Sun, R.G. Zhang, B.J. Wang, Insights into the preference of CHx(x=1-3) formation from CO hydrogenation on Cu(111) surface, Appl. Surf. Sci. 265 (2013) 720-730.
    [22]
    X.C. Xu, J.J. Su, P.F. Tian, D.L. Fu, W.W. Dai, W. Mao, W.K. Yuan, J. Xu, Y.F. Han, J. Phys. Chem. C 119 (2015) 216-227.
    [23]
    G. Prieto, S. Beijer, M.L. Smith, M. He, Y. Au, Z. Wang, D.A. Bruce, K.P. de Jong, J.J. Spivey, P.E. de Jongh, Design and synthesis of copper-cobalt catalysts for the selective conversion of synthesis gas to ethanol and higher alcohols, Angew. Chem. Int. Ed. 126 (2014) 6515-6519.
    [24]
    K. Xiao, X.Z. Qi, Z.H. Bao, X.X. Wang, L.S. Zhong, K.G. Fang, M.G. Lin, Y.H. Sun, CuFe, CuCo and CuNi nanoparticles as catalysts for higher alcohol synthesis from syngas: A comparative study, Catal. Sci. Technol. 3 (2013) 1591-1602.
    [25]
    N.D. Subramanian, G. Balaji, C.S.S.R. Kumar, J.J. Spivey, Development of cobalt-copper nanoparticles as catalysts for higher alcohol synthesis from syngas, Catal. Today 147 (2009) 100-106.
    [26]
    M.Y. Ding, M.H. Qiu, J.G. Liu, Y.P. Li, T.J. Wang, L.L. Ma, C.Z. Wu, Influence of manganese promoter on co-precipitated Fe-Cu based catalysts for higher alcohols synthesis, Fuel 109 (2013) 21-27.
    [27]
    K. Xiao, Z.H. Bao, X.Z. Qi, X.X. Wang. L.S. Zhong, M.G. Lin, K.G. Fang, Y.H. Sun, Unsupported CuFe bimetallic nanoparticles for higher alcohol synthesis via syngas, Catal. Commun. 40 (2013) 154-157.
    [28]
    Z.H. Bao, K. Xiao, X.Z. Qi, X.X. Wang, L.S. Zhong, K.G. Fang, M.G. Lin, Y.H. Sun, J. Energy Chem. 22 (2013) 107-113.
    [29]
    X.P. Shi, H.B. Yu, S. Gao, X.Y. Li, H.H. Fang, R.J. Li, Y.Y. Li, L.J. Zhang, X.L. Liang, Y.Z. Yuan, Synergistic effect of nitrogen-doped carbon-nanotube-supported Cu-Fe catalyst for the synthesis of higher alcohols from syngas, Fuel 210 (2017) 241-248.
    [30]
    L.X. Ling, Q. Wang, R.G. Zhang, D.B. Li, B.J. Wang, Phys. Chem. Chem. Phys. 19 (2017) 30883–30894.
    [31]
    Y.H. Zhao, M.M. Yang, D.P. Sun, H.Y. Su, K.J. Sun, X.F. Ma, X.H. Bao, W.X. Li, Phys. Chem. C 115 (2011) 18247-18256.
    [32]
    R.G. Zhang, G.R. Wang, B.J. Wang, Insights into the mechanism of ethanol formation from syngas on Cu and an expanded prediction of improved Cu-based catalyst, J. Catal. 305 (2013) 238-255.
    [33]
    B.J. Wang, W.S. Guo, L.X. Ling, R.G. Zhang, Appl. Surf. Sci. 488 (2019) 434-444.
    [34]
    B.J. Wang, W.S. Guo, R.G. Zhang, L.X. Ling, Z.Q. Li, J. Phys. Chem. C 123 (2019) 19528-19539.
    [35]
    Y.H. Gao, L. Shi, S.G. Li, Q.H. Ren, Mechanistic insights into higher alcohol synthesis from syngas on Rh/Cu single-atom alloy catalysts, Phys. Chem. Chem. Phys. 22 (2020) 5070-5077.
    [36]
    M.A. Haider, M.R. Gogate, R.J. Davis, Fe-promotion of supported Rh catalysts for direct conversion of syngas to ethanol, J. Catal. 261 (2009) 9-16.
    [37]
    M.L. Smith, N. Kumar, J.J. Spivey, CO adsorption behavior of Cu/SiO2, Co/SiO2, and CuCo/SiO2 catalysts studied by in situ DRIFTS, J. Phys. Chem. C 116 (2012) 7931-7939.
    [38]
    M.A. Petersen, J.A. van den Berg, I.M. Ciobicǎ, P. van Helden, Revisiting CO activation on Co catalysts: Impact of step and kink sites from DFT, ACS Catal. 7 (2017) 1984-1992.
    [39]
    Z. An, X. Ning, J. He, Ga-promoted CO insertion and C-C coupling on Co catalysts for the synthesis of ethanol and higher alcohols from syngas, J. Catal. 356 (2017) 157-164.
    [40]
    W. Wang, Y. Wang, G.C. Wang, Ethanol synthesis from syngas over Cu(Pd)-doped Fe(100): A systematic theoretical investigation, Phys. Chem. Chem. Phys. 20 (2018) 2492-2507.
    [41]
    Y.H. Zhao, K.J. Sun, X.F. Ma, J.X. Liu, D.P. Sun, H.Y. Su, W.X. Li, Carbon chain growth by formyl insertion on rhodium and cobalt catalysts in syngas conversion, Angew. Chem. Int. Ed. 50 (2011) 5447-5450.
    [42]
    Y.H. Wang, W.G. Gao, K.Z. Li, Y.N. Zheng, Z.H. Xie, W. Na, J.G.G. Chen, H. Wang, Chem 6 (2020) 1-12.
    [43]
    Y.Y. Qi, C. Aaserud, A. Holmen, J. Yang, D. Chen, Promotional effect of in situ generated hydroxyl on olefin selectivity of Co-catalyzed Fischer-Tropsch synthesis, Phys. Chem. Chem. Phys. 21 (2019) 24441-24448.
    [44]
    X.M. Zhao, X. Liu, B.Y. Huang, P. Wang, Y. Pei, Hydroxyl group modification improves the electrocatalytic ORR and OER activity of graphene supported single and bi-metal atomic catalysts (Ni, Co, and Fe), J. Mater. Chem. A 7 (2019) 24583-24593.
    [45]
    Y.H. Peng, L.B. Wang, Q.Q. Luo, Y. Cao, Y.Z. Dai, Z.L. Li, H.L. Li, X.S. Zheng, W.S. Yan, J.L. Yang, J. Zeng, Molecular-level insight into how hydroxyl groups boost catalytic activity in CO2 hydrogenation into methanol, Chem 4 (2018) 613-625.
    [46]
    S. Krishnamoorthy, M. Tu, M.P. Ojeda, D. Pinna, E. Iglesia, An investigation of the effects of water on rate and selectivity for the Fischer-Tropsch synthesis on cobalt-based catalysts, J. Catal. 211 (2002) 422-433.
    [47]
    S. Logdberg, M. Boutonnet, J.C. Walmsley, S. Jaras, A. Holmen, E.A. Blekkan, Effect of water on the space-time yield of different supported cobalt catalysts during Fischer-Tropsch synthesis, Appl. Catal. A-Gen. 393 (2011) 109-121.
    [48]
    A.K. Dalai, T.K. Das, K.V. Chaudhari, G. Jacobs, B.H. Davis, Fischer-Tropsch synthesis: Water effects on Co supported on narrow and wide-pore silica, Appl. Catal. A-Gen. 289 (2005) 135-142.
    [49]
    E. Jimenez-Barrera, P. Bazin, C. Lopez-Cartes, F. Romero-Sarria, M. Daturi, J.A. Odriozola, Appl. Catal. B-Environ. 237 (2018) 986-995.
    [50]
    S. Storsaeter, OE. Borg, E.A. Blekkan, A. Holmen, Study of the effect of water on Fischer-Tropsch synthesis over supported cobalt catalysts, J. Catal. 231(2005) 405-419.
    [51]
    G.T.K.K. Gunasooriya, A.P. van Bavel, H.P.C.E. Kuipers, M. Saeys, Key role of surface hydroxyl groups in C-O activation during Fischer-Tropsch synthesis, ACS Catal. 6 (2016) 3660-3664.
    [52]
    H. Zha, X.Q. Dong, Y.Z. Yu, M.H. Zhang, Hydrogen-assisted versus hydroxyl-assisted CO dissociation over Co-doped Cu(111): A DFT study, Surf. Sci. 669 (2018) 114-120.
    [53]
    J. Schweicher, A. Bundhoo, N. Kruse, Hydrocarbon chain lengthening in catalytic CO hydrogenation: Evidence for a CO-insertion mechanism, J. Am. Chem. Soc. 134 (2012) 16135-16138.
    [54]
    B. Bai, H. Bai, H.J. Cao, Z.H. Gao, Z.J. Zuo, W. Huang, Phys. Chem. Chem. Phys. 20 (2018) 12845-12857.
    [55]
    R.G. Zhang, C. Wei, D.B. Li, Z. Jiang, B.J. Wang, L.X. Ling, M.H. Fan, J. Catal. 377 (2019) 1-12.
    [56]
    G. Kresse, J. Furthmuller, Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set, Phys. Rev. B 54 (1996) 11169-11186.
    [57]
    G. Kresse, J. Hafner, Ab initio molecular dynamics for open-shell transition metals, Phys. Rev. B 48 (1993) 13115-13118.
    [58]
    J.P. Perdew, K. Burke, M. Ernzerhof, Generalized gradient approximation made simple, Phys. Rev. Lett. 77 (1996) 3865-3868.
    [59]
    H.J. Monkhorst, J.D. Pack, Special points for Brillonin-zone integrations, Phys. Rev. B 13 (1976) 5188-5192.
    [60]
    P.L. Hansen, J.B. Wagner, S. Helveg, J.R. Rostrup-Nielsen, B.S. Clausen, H. Topsoee, Atom-resolved imaging of dynamic shape changes in supported copper nanocrystals, Science 295 (2002) 2053-2055.
    [61]
    G. Henkelman, B.P. Uberuaga, H. Jonsson, A climbing image nudged elastic band method for finding saddle points and minimum energy paths, J. Chem. Phys. 113 (2000) 9901-9904.
    [62]
    R.A. Olsen, G.J. Kroes, G. Henkelman, A. Arnaldsson, H. Jonsson, Comparison of methods for finding saddle points without knowledge of the final states, J. Chem. Phys. 121 (2004) 9776-9792.
    [63]
    G. Henkelman, H. Jonsson, Improved tangent estimate in the nudged elastic band method for finding minimum energy paths and saddle points, J. Chem. Phys. 113 (2000) 9978-9985.
    [64]
    W. Fang, W.J. Liu, X.J. Guo, X.H. Lu, L.H. Lu, J. Phys. Chem. C 115 (2011) 8622-8629.
    [65]
    W.G. Reimers, M.A. Baltanas, M.M. Branda, CO, J. Mol. Model. 20 (2014) 2270.
    [66]
    M.K. Zhuo, A. Borgna, M. Saeys, Effect of the CO coverage on the Fischer-Tropsch synthesis mechanism on cobalt catalysts, J. Catal. 297 (2013) 217-226.
    [67]
    M.P. Andersson, S. Dobberschutz, K.K. Sand, D.J. Tobler, J.J. de Yoreo, S.L.S. Stipp, A microkinetic model of calcite step growth, Angew. Chem. Int. Ed. 128 (2016) 11252-11256.
    [68]
    J.M. Lu, A. Heyden, Theoretical investigation of the reaction mechanism of the hydrodeoxygenation of guaiacol over a Ru(0001) model surface, J. Catal. 321 (2015) 39-50.
    [69]
    L. Bui, A. Bhan, A kinetic model for propylene oxidation on a mixed metal oxide catalyst, Appl. Catal. A-Gen. 564 (2018) 1-12.
    [70]
    F. Polo-Garzon, J.K. Scott, D.A. Bruce, Microkinetic model for the dry reforming of methane on Rh doped pyrochlore catalysts, J. Catal. 340 (2016) 196-204.
    [71]
    A. Salcedo, B. Irigoyen, Unraveling the origin of ceria activity in water-gas shift by first-principles microkinetic modeling, J. Phys. Chem. C 124 (2020) 7823-7834.
    [72]
    V. Subramani, S.K. Gangwal, A review of recent literature to search for an efficient catalytic process for the conversion of syngas to ethanol, Energ. Fuel 22 (2008) 814-839.
    [73]
    J. Schumann, A.J. Medford, J.S. Yoo, Z.J. Zhao, P. Bothra, A. Cao, F. Studt, F. ACS Catal. 8 (2018) 3447-3453.
    [74]
    M. Gupta, M.L. Smith, J.J. Spivey, Heterogeneous catalytic conversion of dry syngas to ethanol and higher alcohols on Cu-based catalysts, ACS Catal. 1 (2011) 641-656.
    [75]
    M. Ao, G.H. Pham, J. Sunarso, M.O. Tade, S.M. Liu, Active centers of catalysts for higher alcohol synthesis from syngas: A review, ACS Catal. 8 (2018) 7025-7050.
    [76]
    H. Xiao, T. Cheng, W.A. Goddard, J. Am. Chem. Soc. 139 (2017) 130-136.
    [77]
    H.Y. Zheng, R.G. Zhang, Z. Li, B.J. Wang, Insight into the mechanism and possibility of ethanol formation from syngas on Cu(100) surface, J. Mol. Catal. A-Chem. 404-405 (2015) 115-130.
    [78]
    R.G. Zhang, X.C. Sun, B.J. Wang, J. Phys. Chem. B 117 (2013) 6594-6606.
    [79]
    R.G. Zhang, F. Liu, B.J. Wang, Catal. Sci. Technol. 6 (2016) 8046-8054.
    [80]
    F. Besenbacher, I. Chorkendorff, B.S. Clausen, B. Hammer, A.M. Molenbroek, J.K. Noerskov, I. Stensgaard, Design of a surface alloy catalyst for steam reforming, Science 279 (1998) 1913-1915.
    [81]
    J.D. Li, E. Croiset, L. Ricardez-Sandoval, Methane dissociation on Ni(100), Ni(111), and Ni(553): A comparative density functional theory study, J. Mol. Catal. A-Chem. 365 (2012) 103-114.
    [82]
    P. Hu, W. Dai, Computer simulation and density functional theory study on relationship between structure of amino acid and inhibition performance, Mater. Res. Innov. 16 (2012) 67-72.
    [83]
    P. Hu, D.A. King, M.H. Lee, M.C. Payne, Orbital mixing in CO chemisorption on transition metal surfaces, Chem. Phys. Lett. 246 (1995) 73-78.
    [84]
    S.S. Sung, R. Hoffmann, How carbon monoxide bonds to metal surfaces, J. Am. Chem. Soc. 107 (1985) 578-584.
    [85]
    A. Alvarez, M. Borges, J.J. Corral-Perez, J.G. Olcina, L.J. Hu, D. Cornu, R. Huang, D. Stoian, A. Urakawa, CO2 activation over catalytic surfaces, Chem. Phys. Chem. 18 (2017) 3135-3141.
    [86]
    P. Zhao, Y.R. He, D.B. Cao, H.W. Xiang, H.J. Jiao, Y. Yang, Y.W. Li, X.D. Wen, J. Phys. Chem. C 123 (2019) 6508-6515.
    • Relative Articles
    • Supplements(0)
    • Cited By
  • 加载中

Catalog

    通讯作者: 陈斌, bchen63@163.com
    • 1. 

      沈阳化工大学材料科学与工程学院 沈阳 110142

    1. 本站搜索
    2. 百度学术搜索
    3. 万方数据库搜索
    4. CNKI搜索
    Get Citation
    PDF
    XML

    Article Metrics

    Article views (153) PDF downloads(19) Cited by()
    Proportional views

    Publish With GEE

    Contact

    • Email：gee@ipe.ac.cn
    • Tel：010-82627075
    • Address：North 2nd street, Zhongguancun, Haidian District, Beijing, China

    Links

    京ICP备10002620号-1京公网安备 11010802039050号

    Supported by: Beijing Renhe Information Technology Co. Ltd    

    /

    DownLoad:  Full-Size Img  PowerPoint
    Return
    Return