Plenary Lecturer

Professor Emiel Hensen

AffiliationDepartment of Chemical Engineering, Eindhoven University of Technology
AddressHet Kraneveld 14, 5612 AZ Eindhoven, The Netherlands
E-maile.j.m.hensen@tue.nl
Websitehttps://www.tue.nl/en/research/researchers/emiel-hensen
Educational Background1995-2000, Ph.D., Chemical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
Research InterestsHeterogeneous catalysis, Inorganic Chemistry, Materials Chemistry

Biography

Emiel Hensen received his BS, MS and PhD degrees, in chemical engineering, from Eindhoven University of Technology. Before joining the Department of Chemical Engineering of this university as a full professor in 2009, he was affiliated with the University of Amsterdam, Shell Research, Eindhoven University of Technology and KU Leuven. He was a visiting professor at Hokkaido University in Japan in 2016. He is a member of the management team of the gravitation program Multiscale Catalytic Energy Conversion, a member of the Advanced Research Center Chemical Building Blocks Consortium, and chairman of the Netherlands Institute for Catalysis Research (NIOK). Hensen was dean of the Department of Chemical Engineering and Chemistry at Eindhoven University of Technology from 2016 to 2020. He received Veni, Vidi, and Vici personal grants from the Netherlands Organization for Scientific Research. He is an editor of Applied Catalysis B and editorial board member of ACS Catalysis and Journal of Catalysis. He has published over 680 scientific papers, receiving more than 40,000 citations with an h-index of 105. His research focuses on the fundamental and applied aspects of catalytic materials relevant to clean and sustainable processes for producing energy carriers and chemicals.

Publications

  1. V. Muravev, G. Spezzati, Y. Su, A. Parastaev , F. Chiang, A. Longo, C. Escudero, N. Kosinov and E.J.M. Hensen, 'Interface dynamics of Pd-CeO2 single-atom catalysts during CO oxidation', Nature Catalysis 4 (2021) 469-478.
  2. V. Muravev, A. Parastaev, Y. van den Bosch, B. Ligt, N. Claes, S. Bals, N. Kosinov and E.J.M. Hensen, ‘Size of cerium dioxide support nanocrystals dictates reactivity of highly dispersed palladium catalysts’, Science 380 (2023) 1174-1178.
  3. Z. Luo, C. Liu, A. Radu, D.F. de Waard, Y. Wang, J.T. Behaghel de Bueren, P.D. Kouris, M.D. Boot, J. Xiao, H. Zhang, R. Xiao, J. Luterbacher and E.J.M. Hensen, ‘Carbon-carbon cleavage for a lignin refinery’, Nature Chemical Engineering 1 (2024) 61-72.
  4. P. Wang, F.-K. Chiang, J. Chai, A.I. Dugulan, J. Dong, W. Chen, R.J.P. Broos, B. Feng, Y. Song, Y. Lv, Q. Lin, R. Wang, I.A.W. Filot, Z. Men and E.J.M. Hensen, ‘Efficient conversion of syngas to linear α-olefins by phase-pure χ-Fe5C2’, Nature 635 (2024) 102-107.

Abstract

Catalysis at Interfaces: Atom-Efficient Metal Catalysts based on Single Atoms, Clusters and Nanoparticles

Efficient utilization of transition metals is critical for optimizing heterogeneous catalysts. Established design rules for nanoparticle catalysts often suggest that sub-optimal metal dispersion can enhance catalytic activity. Additionally, the interactions between metal nanoparticles and typical supporting oxides significantly influence catalytic performance. Notably, specific sites at the metal-support interface can exhibit exceptional reactivity. In this contribution, I will review the structure sensitivity of both monometallic and bimetallic catalysts and highlight strategies for tuning metal-support interfaces to enhance CO2 hydrogenation and CO oxidation performance. Our approach integrates experimental synthesis of uniform active phases, operando characterization, and transient kinetic analysis, supplemented by density functional theory (DFT) calculations for mechanistic insights and microkinetic simulations.

The first example focuses on breaking structure sensitivity through the use of cobalt nanoparticles on ceria-zirconia supports. We first determine how the size of the support crystallites can stabilize cobalt nanoparticles. Following this, we explore the effects of incomplete cobalt oxide reduction, which leads to cobalt-cobalt oxide interfaces that demonstrate significantly enhanced CO2 methanation activity compared to conventional cobalt nanoparticle catalysts. This work illustrates the potential of utilizing small metal clusters stabilized on an oxide to achieve high CO2 methanation rates.

Next, I will discuss how the size of CeO2 crystallites can profoundly impact the stability and reactivity of single metal atoms. The enhanced reducibility of CeO2 nanoparticles, compared to bulk counterparts, facilitates the retention of single palladium (Pd) atoms, resulting in improved kinetics for low-temperature CO oxidation.

The final example shows a Cu-modified zincosilicate porous material designed for CO2 hydrogenation to methanol. We synthesized a novel Cu-Zn catalyst through ion exchange of Cu into crystalline porous zincosilicate CIT-6, which exhibited superior CO2 hydrogenation rates to methanol when compared to commercial CuZnAl catalysts. The distinctively dispersed Cu particles adjacent to isolated Zn2+ species present a novel type of active site for methanol synthesis, differing from traditional active phases like Cu-Zn alloys or Cu decorated with ZnOx. In situ IR spectroscopy further revealed the formation of Zn-formate species during CO2 hydrogenation, highlighting that Zn2+ ions effectively stabilize formate as a reaction intermediate in the conversion of CO2 to methanol.

Professor Younan Xia

AffiliationSchool of Chemistry and Biochemistry, Georgia Institute of Technology
AddressNorth Avenue, Atlanta, GA 30332
E-mailyounan.xia@bme.gatech.edu
Website https://www.nanocages.com/
Educational Background1993-1996, Ph.D., Physical Chemistry, Harvard University
Research InterestsNanocrystal synthesis, Nanomedicine, Structure-property relationship of shape-controlled nanocrystals, Catalysis

Biography

Dr. Younan Xia is the Brock Family Chair and Georgia Research Alliance (GRA) Eminent Scholar at the Georgia Institute of Technology. He received his B.S. degree in chemical physics from the University of Science and Technology of China (USTC) in 1987, M.S. degree in chemistry from University of Pennsylvania (with Alan G. MacDiarmid) in 1993, and Ph.D. degree in physical chemistry from Harvard University (with George M. Whitesides) in 1996. His group invented numerous nanomaterials with well-controlled properties for use in applications related to plasmonics, electronics, display, catalysis, energy conversion, controlled release, drug delivery, nanomedicine, and regenerative medicine. Notably, the silver nanowires invented by his group has been commercialized for the manufacturing of flexible, transparent, and conductive coatings pivotal to applications such as touchscreen display, flexible electronics, and photovoltaics. His technology on the alignment of electrospun nanofibers has been commercialized for multiple clinical products in regenerative medicine, including those for the management of surgical and trauma wounds. Xia has co-authored more than 900 publications in peer-reviewed journals, together with a total citation of about 200,000 and an h-index of 220. He has been named a Top 10 Chemist and Materials Scientist based on the citation data. He has received many prestigious awards, including the Linus Pauling Medal (2024), ACS Award for Creative Invention (2023), MRS Medal (2017), ACS Award in the Chemistry of Materials (2013), NIH Director's Pioneer Award (2006), and NSF CAREER Award (2000). More information can be found at http://www.nanocages.com.

Abstract

Colloidal Metal Nanocrystals as the Next Generation Catalytic Materials

Heterogeneous catalysis is of critical importance to the world’s economy as it is involved in more than 90% of the chemical processes. Among various catalytic materials, metals easily stand out because of their ability to donate and accept electrons for catalyzing both reduction and oxidation reactions, as well as the capability to adopt different oxidation states depending on the reaction environment. Heterogeneous catalysts based on metals are indispensable for the production of numerous industrial chemicals and pharmaceuticals. Recent success in the synthesis of colloidal metal nanocrystals with controlled shapes offers many opportunities to not only maneuver their physicochemical properties but also optimize their figure of merits in a wide variety of applications. In particular, heterogeneous catalysis and surface science have benefited enormously from the availability of this new class of nanomaterials as the atomic structure presented on the surface of a nanocrystal is ultimately determined by its geometric shape. The immediate advantages may include significant enhancement in catalytic activity and/or selectivity and substantial reduction in materials cost while providing a well-defined model system for mechanistic study. With a focus on the monometallic system, I aim to provide a comprehensive account of recent progress in the development of colloidal metal nanocrystals with controlled shapes, in addition to their remarkable performance in a large number of catalytic and electrocatalytic reactions. It is hoped that this talk offers the impetus and roadmap for the development of next-generation catalysts vital to a broad range of industrial applications.

Professor Hsisheng Teng

AffiliationDepartment of Chemical Engineering, National Cheng Kung University
E-mailhteng@mail.ncku.edu.tw
Websitehttp://www.che.ncku.edu.tw/FacultyWeb/TengH/home.html
Educational Background1992, Ph.D., Chemical Engineering, Brown University, USA
Research Interests
  • Photocatalysis for H2 Production and CO2 Conversion
  • Lithium Ion Batteries and Supercapacitors

Biography

Hsisheng Teng is the University Professor of National Cheng Kung University and the Scientific Coordinator of the TW-DE joint battery research program since September 2016. His research focuses on the in-depth understanding of photocatalytic reforming of biomass into solar fuels and reduction of CO2 into valuable chemicals and development of gel-state and solid-state electrolytes for high-energy lithium ion batteries and electrochemical capacitors. He is an international pioneer in the development of graphene-based photocatalysts for water splitting and co-author of 210 scientific papers with H-Index of 65 and cites per paper of >68 (Web of Science). He has received a number of awards including: Academic Award (Ministry of Education), Scientific Chair Professor Award (Yu-Ziang Hsu Foundation) Research Excellence Award (Ministry of Science and Technology, 3 times), Outstanding Engineering Professor Award (Taiwan Institute of Engineers), and Thomson Reuters Taiwan Research Front Award. He was the Present of the Electrochemical Society of Taiwan and the Taiwan Representative of the International Society of Electrochemistry. He was the Editor-in-Chief of the Taiwan Institute of Chemical Engineers.

Publications

  1. Putri, NP; Nguyen, VC; Sanoe, M; Lee, YL; Teng, H* “Concurrent Photocatalytic Bicarbonate (Aqueous-CO2) Reduction and Xylose Reforming to Produce Compounds from C−C Coupling”, Chemical Engineering Journal 2024, 486, 150318. https://doi.org/10.1016/j.cej.2024.150318
  2. Nguyen, VC; Sanoe, M; Putri, NP; Lee, YL; Teng, H* “Co-catalyst Design to Control Charge Transfer and Product Composition for Photocatalytic H2 Production and Biomass Reforming”, Sustainable Energy & Fuels 2024, 8, 1412–1423 https://doi.org/10.1039/d3se01544k
  3. Nguyen, ML; Nguyen, VC; Lee, YL; Jan, JS; Teng, H* “Synergistic Combination of Ether-Linkage and Polymer-in-Salt for Electrolytes with Facile Li+ Conducting and High Stability in Solid-State Lithium Batteries”, Energy Storage Materials 2024, 65, 103178. https://doi.org/10.1016/j.ensm.2024.103178
  4. Nguyen, VC; Nimbalkar, DB; Huong, VH; Lee, YL; Teng, H* “Elucidating the Mechanism of Photocatalytic Reduction of Bicarbonate (Aqueous CO2) into Formate and Other Organics”, Journal of Colloid and Interface Science 2023, 649, 918-928. https://doi.org/10.1016/j.jcis.2023.06.155
  5. Lin, YH; Wu, LT; Yu-Ting Zhan, YT; Jiang, JC; Lee, YL; Jan, JS; Teng, H* “Self-Assembly Formation of Solid-Electrolyte Interphase in Gel Polymer Electrolytes for High Performance Lithium Metal Batteries”, Energy Storage Materials 2023, 61, 102868. https://doi.org/10.1016/j.ensm.2023.102868
  6. Shih, CY; Wang, PT; Wei-Pang Chung, WP; Wang, WH; Chiang, IT; Wu-Chou Su, WC; Wei-Lun Huang, WL;* Teng, H* “Concise Nanotherapeutic Modality for Cancer Involving Graphene Oxide Dots in Conjunction with Ascorbic Acid”, Nanoscale 2023, 15, 10232-10243. https://doi.org/10.1039/d3nr00431g
  7. Nguyen, HTT; Nguyen, DH; Zhang, QC; Nguyen, VC; Lee, YL; Jan, JS; Teng, H* “Facile Li+ Transport in Interpenetrating O- and F-Containing Polymer Networks for Solid-State Lithium Batteries”, Advanced Functional Materials 2023, 33, 2213469. https://doi.org/10.1002/adfm.202213469
  8. Nimbalkar, DB; Nguyen, VC; Shih, CY; Teng, H* “Melem-derived poly(heptazine imide) for effective charge transport and photocatalytic reforming of cellulose into H2 and biochemicals under visible light”, Applied Catalysis B-Environmental 2022, 316, 121601. 
  9. https://doi.org/10.1016/j.apcatb.2022.121601
  10. Lin, YH; Shih, CY; Subramani, R; Lee, YL; Jan, JS; Chiu, CC; Teng, H* “Ternary-Salt Gel Polymer Electrolyte for Anode-Free Lithium Metal Batteries with an Untreated Cu Substrate”, Journal of Materials Chemistry A 2022, 10, 4895-4905. https://doi.org/10.1039/d1ta09819e
  11. Pham, MN; Subramani, R; Yu-Hsing Lin, YH; Lee, YL; Jan, JS; Chiu, CC; Teng, H* “Acylamino-Functionalized Crosslinker to Synthesize All-Solid-State Polymer Electrolytes for High-Stability Lithium Batteries”, Chemical Engineering Journal 2022, 430, 132948. https://doi.org/10.1016/j.cej.2021.132948
  12. Nguyen, VC; Nimbalkar, DB; Nam, LD; Lee, YL; Teng, H* “Photocatalytic Cellulose Reforming for H2 and Formate Production by Using Graphene Oxide-Dot Catalysts”, ACS Catalysis 2021, 11, 4955-4967. https://doi.org/10.1021/acscatal.1c00217

Abstract

Radical Interacting Mechanisms of Photocatalytic CO2 Reduction Combined with CH3OH Reforming

The increasing concentration of atmospheric CO2 due to human activities has become a major global concern, contributing significantly to climate change. While photocatalytic reduction of CO2 offers a promising strategy for converting this greenhouse gas into valueadded chemicals using renewable solar energy, significant challenges remain in terms of efficiency and selectivity. The competition from photocatalytic H2 evolution and the low efficiency of oxidative counter reactions are key limitations that need to be addressed.

Our work presents a novel approach to selective C2 production through concurrent photocatalytic reactions of reductive CO2 conversion and oxidative CH3OH reforming. The key points of our work are summarized below:

(1) Strategic System Design: We demonstrate an active potassium poly(heptazine imide) (K-PHI) photocatalyst decorated with Pt as a co-catalyst in an alkaline aqueous system, enabling effective interaction between CO2 and CH3OH as electron acceptor and donor respectively.

(2) Exceptional Selectivity Achievement: Our system achieved a remarkable 95% selectivity for acetate (CH3COO⁻) production in the liquid phase when the CH3OH:CO2 feedstock ratio was close to 2:1, with acetate exclusively produced from the combination of CH3OH and CO2. When the CH3OH:CO2 ratio became higher (at a fixed CO2 feed), the CO2 conversion increased and the contribution of CH3COO− production from CO2 coupling also increased.

(3) Mechanistic Insights: Through comprehensive analysis of intermediates and radical species, we unraveled the complete reaction mechanism and pathways involved in this photocatalysis system, demonstrating how charge accumulation control in the photocatalyst can effectively modulate product selectivity.　

This work provides valuable insights into achieving selective C2 production through photocatalytic CO2 reduction and CH3OH reforming, offering an advantageous pathway toward net-zero emission goals.