(6ap) Development of Novel Single-Site and Isolated Bimetallic Alloy Catalysts for C-H Bond Activation

Research Interests:

 

My research interests are primarily focused on the development of novel single-site and isolated bimetallic alloy catalysts and their application in heterogeneous catalysis, particular in the activation of C-H bonds of alkanes. In an era of cheap and abundant alkanes, there is a growing interest in the conversion of alkanes, to value-added products, in which C-H activation is the elementary first step. Despite extensive studies, C-H activation under mild conditions continues to be the â??holy-grailâ? of catalysis. The difficulty in C-H activation arises not only from the relatively inert nature of C-H bond, but also from the poor selectivity, which leads to unattractive products, carbon dioxide and water.

One particular important application of C-H activation is the methane activation and conversion to more valuable products, such as methanol and acetic acid. Many studies over the past several decades have failed to show promise for practical applications of the direct methane to desired liquid products. Examples include the approaches using Pd and Pt homogeneous catalysts, the conversion over CuFe/ZSM-5 catalysts using expensive H₂O₂ as the oxidant in aqueous media, and the non-catalytic two-step approaches focusing on Cu/MOR catalysts, which involves first the activation and conversion of methane at high temperatures, and second an ex-situ extraction process at room temperature. This stoichiometric reaction produces only trace amount of methanol; therefore is economically impractical. In my previous research, I have found the first truly catalytic cycle of the direct conversion of methane to practical yields of methanol and acetic acid with using molecular oxygen as the oxidant at low temperatures. The reactions are performed in aqueous media, under mild pressures of methane, oxygen and carbon monoxide, the latter used as catalyst promoter and reactant if the desired product is acetic acid. The catalysts are Rh/ZSM-5 with tunable high selectivity to acetic acid, and Cu promoted Ir/ZSM-5 with tunable high selectivity to methanol. The active sites are likely isolated Rh and Ir cations anchored on the internal walls of zeolite. This work opens a new door for the solving of long-standing problem of the direct catalytic conversion of methane to desirable liquid products using heterogeneous catalysts under mild operating conditions. Nevertheless, further investigations that avoid using precious metals and carbon monoxide are warranted.

My near future research will continue on the developing of novel heterogeneous catalysts for the activation of C-H bonds. In particular, I would like to using my obtained knowledge and experience to design novel single-site and isolated bimetallic alloy catalysts using non-precious metal to directly convert methane to value-added products.

Research Experience

My academic career path has been a blend of two main fields in heterogeneous catalysis. The first is the UHV study of the interaction of H₂O, CH₄, H₂, CO, CO₂ with single crystal surfaces, as well as with supported nanoparticles. The second involves synthesis of heterogeneous catalysts, performing catalytic measurements under realistic conditions, and in-situ characterizations with APXPS, XANES, EXAFS, DRIFTS, and various other techniques. In the meantime, I had trained and supervised new graduate students to start their respective projects. These experiences are very helpful to maintain a productive leading-edge research group when I start my own academic career.

Teaching Interests: 

 

In addition to doing research, I also had a strong interest in teaching undergraduate and graduate students. I spent a semester teaching high-school students basic science when I was an undergraduate student. As a graduate student, I taught courses in physical chemistry and general chemistry. Given my background and experience in chemistry and catalysis, I am most interested in teaching classes related to physical chemistry and interdisciplinary techniques used in heterogeneous catalysis.

Selected publications

 

25. J. Shan, M. Li, L. F. Allard, S. Lee, M. Flytzani-Stephanopoulos

Direct conversion of methane to methanol or acetic acid with molecular oxygen on Rh- or Ir-ZSM-5 catalysts

Submitted, under the revision.

24. J. Shan, N. Janvelyan, H. Li, J. Liu, T. M. Egle, J. Ye, M. M. Biener, J. Biener, C. M. Friend, M. Flytzani-Stephanopoulos

Selective non-oxidative dehydrogenation of ethanol to acetaldehyde and hydrogen on highly dilute NiCu alloys

Submitted, under the revision.

23. J. Shan, S. Zhang, T. Choksi, L. Nguyen, C. S. Bonifacio, Y. Li, W. Zhu, Y. Tang, Y. Zhang, J. C. Yang, J. Greeley, A. I. Frenkel, F. Tao

Tuning catalytic performance through a single or sequential post-synthesis reaction(s) in a gas phase

Submitted, under the revision.

 

22. J. Shan, F. R. Lucci, J. Liu, M. El-Soda, M. D. Marcinkowski, L. F. Allard, E. C. H. Sykes, M. Flytzani-Stephanopoulos

Water co-catalyzed selective dehydrogenation of methanol to formaldehyde and hydrogen

Surface Science, 2016, 650, 121-129.

21. S. Zhang, J. Shan, L. Nie, L. Nguyen, Z. Wu, F. Tao

In situ studies of surface of NiFe₂O₄ catalyst during complete oxidation of methane

Surface Science, 2016, 648, 156-162.

 

20. C. S. Bonifacio, J. Shan, F. Tao, J. C. Yang

Atomic-scale characterization of restructured PtCu nanocubes

Microscopy and Microanalysis, 2015, 21, 1067-1068.

19. F. Tao, J. Shan, L. Nguyen, Z. Wang, S. Zhang, L. Zhang, Z. Wu, W. Huang, S. Zeng, P. Hu

Understanding of complete oxidation of methane on spinel oxides on a molecular level

Nature Communications, 2015, 6, 7798.

18. J. Shan, L. Nguyen, S. Zhang, F. Tao

Waterâ??gas shift on Pd/α-MnO₂ and Pt/α-MnO₂

Catalysis Letters, 2015, 145, 1571-1580.

 

17. J. Shan, W. Huang, L. Nguyen, Y. Yu, S. Zhang, Y. Li, A. I. Frenkel, F. Tao

Conversion of methane to methanol with a bent mono(µ-oxo)dinickel anchored on internal surface of micro-pores

Langmuir, 2014, 30, 8558-8569.

 

16. S. Zhang, J. Shan, Y. Zhu, L. Nguyen, W. Huang, H. Yoshida, S. Takeda, F. Tao

Restructuring transition metal oxide nanorods for 100% selectivity in reduction of nitric oxide with carbon monoxide

Nano letters, 2013, 13, 3310-3314.

 

15. S. Zhang, J. Shan, Y. Zhu, A.I. Frenkel, A. Patlolla, W. Huang, S. Yoon, L. Wang, H. Yoshida, S. Takeda, F. Tao

WGS catalysis and in-situ studies of CoO_1-x, PtCo_n/Co₃O₄, and Pt_mCo_mâ??/CoO_1-x nanorod catalysts

Journal of the American Chemical Society, 2013, 135, 8283-8293.

 

14. J. Shan, Y. Zhu, S. Zhang, T. Zhu, R. Seigei, F. Tao

Catalytic performance and in-situ surface chemistry of pure α-MnO₂ nanorods in selective reduction of NO and N₂O with CO

Journal of Physical Chemistry C, 2013, 117,8329-8335

13. J. Shan, A. Chakradhar, K. Andeson, J. Schmidt, S. Dhuey, U. Burghaus

Butane adsorption on silica supported MoO_x clusters nanofabricated by electron beam lithography

Nanotechnology for Sustainable Energy, American Chemical Society, Washington DC, USA, 2013, Chapter 12, pp 295-310.

 

12. J. Shan, A. Chakradhar, M. Komaneni, M. Lu, U. Burghaus

Rim effects in the adsorption of CO₂ on silica supported copper oxide clusters - utilizing electron beam lithography

Journal of Physical Chemistry C, 2012, 116, 18930-18936.

 

11. A. Chakradhar, J. Shan, M. Komaneni, M. Lu, U. Burghaus

Identifying rims along nano-sized clusters as catalytically active sites â?? The case of CuO_x/silica model catalysts nanofabricated by electron beam lithography

Chemical Physics Letters, 2012, 544, 70-72.

 

10. M. Komaneni, J. Shan, A. Chakradhar, E. Kadossov, S. Cabrini, U. Burghaus

Adsorption dynamics of CO on silica supported CuO_x clusters: utilizing electron beam lithography to study methanol synthesis model systems

Journal of Physical Chemistry C, 2012, 116, 5792-5801.

 

9. C. Hahn, J. Shan, Y. Liu, O. Berg, A. W. Kleyn, L. B. F. Juurlink

Employing a cylindrical single crystal in gas-surface dynamics

Journal of Chemical Physics, 2012, 136, 114201.

 

8. J. Shan, A. Chakadhar, Z. Yu, U. Burghaus

Adsorption of water on a hydrophobic surface â?? the case of antimony(111)

Chemical Physics Letters, 2011, 517, 46-50.

 

7. J. Shan, M. Komameni, U. Burghaus

Adsorption dynamics of CO on copper and gold clusters supported on silica â??how special is nanogold?

Chemical Physics Letters, 2011, 517, 59-61.

 

6. M. Komaneni, J. Shan, U. Burghaus

Adsorption dynamics of CO on silicaâ??supported Cu clusters: a molecular beam scattering study

Journal of Physical Chemistry C, 2011, 115, 16590-16597.

5. C. Hahn, J. Shan, I. M. N. Groot, A. W. Kleyn, L. B. F. Juurlink

Selective poisoning of active sites for D₂ dissociation on platium

Catalysis Today, 2010, 154, 85-91.

 

4. J. Shan, A. W. Kleyn, L. B. F. Juurlink

Adsorption of molecular hydrogen on an ultrathin layer of Ni(111) hydride

Chemical Physics Letters, 2009, 474, 107-111.

3. J. Shan, A. W. Kleyn, L. B. F. Juurlink

Identification of hydroxyl on Ni(111)

Chemphyschem, 2009, 10, 270-275.

2. J. Shan, J. F. M. Aarts, A. W. Kleyn, L. B. F. Juurlink

Co-adsorption of water and hydrogen on Ni(111)

Physical Chemistry Chemical Physics, 2008, 10, 4994-5003.

1. J. Shan, J. F. M. Aarts, A. W. Kleyn, L. B. F. Juurlink

The interaction of water with Ni(111) and H/Ni(111) studied by TPD and HREELS

Physical Chemistry Chemical Physics, 2008, 10, 2227-2232.