(382w) Designing Advanced Materials for High-Performance Chemical Energy Conversion

Passionate about developing and optimizing advanced nanostructured catalysts and materials to improve the efficiency and durability of chemical and energy-related systems. Interested in translating fundamental insights into scalable, practical solutions for industrial applications, with a strong focus on materials design and modification, characterization, and electrochemical performance validation.

Highlights of qualifications

• Seven years of hands-on synthesis experience and developing catalysts and materials for various reactions.
• Fabrication of electrodes and utilized them for industrial-related proton exchange membrane (PEM) water electrolysis.
• Skilled in the characterization of nanostructured materials, including transmission electron microscopy (TEM), high-resolution TEM (HRTEM), X-ray diffraction (XRD), gas chromatography (GC), high-performance liquid chromatography (HPLC), ion chromatography (IC), Fourier-transform infrared spectroscopy (FTIR), X-ray absorption spectroscopy (XAS), UV/Visible spectrophotometer, nuclear magnetic resonance (NMR), potentiostat (CV, LSV, EIS, etc.).
• Delivered technical presentations and communicated complex findings to diverse audiences including collaborators from different scientific backgrounds.
• Solid collaboration and leadership skills in multidisciplinary teams.

Research experience

My research focuses on the design and development of advanced nanostructured catalysts and functional materials to improve the performance of chemical and energy conversion systems. I have extensive experience in materials design and modification, catalyst support engineering, and interfacial optimization to upgrade catalyst performance. My work integrates synthesis, structural characterization (such as TEM, XRD, and XPS), and performance evaluation using GC, HPLC, and other analytical techniques. One case study is reducing the iridium loading on support material for oxygen evolution reaction (OER) to decrease the overall catalyst cost. We first developed a framework for designing active and stable catalysts for OER based on density functional theory (DFT) predictions and experimental verification using well-defined thin film catalysts and then extended to practical powder-based catalysts with iridium oxide deposited on titanium nitride nanoparticles (IrO_x/TiN NPs). By using TiN as a conductive support, we successfully reduced the Ir loading to 30 wt%, compared to benchmark IrO₂ catalysts (85.7 wt%), while still achieving excellent acidic OER performance, that requiring only 1.69 V to achieve a current density of 1 A cm^-2, lower than the benchmark IrO₂ (above 1.8 V) in a proton exchange membrane water electrolyzer (PEMWE) cell. This study highlights the importance of combining computational design, precise materials engineering, and practical validation to develop cost-effective, high-performance catalysts for potential industrial energy applications.

Selected publications:

1) Han, X., Mou, T., Kang, S., Liu, P., Chen, J-G., Enhancing acidic oxygen evolution activity by controlling oxidation state of iridium. Angewandte Chemie International Edition, 2025, e202507468. https://doi.org/10.1002/anie.202507468.

2) Han, X., Mou, T., Islam, A., Kang, S., Chang. Q., Xie, Z., Zhao, X., Sasaki, K., Rodriguez, J-A., Liu, P., Chen, J-G., Theoretical prediction and experimental verification of IrOx supported on titanium nitride for acidic oxygen evolution reaction. Journal of the American Chemical Society, 2024, 146, 16499-16510.

3) Gao, Q., Han, X. (co-first author), Liu, Y., Zhu, H., Electrifying energy and chemical transformations with single-atom alloy nanoparticle catalysts. ACS Catalysis, 2024, 14, 6045-6061.

4) Han, X., Wu, B., Wang, Y., Nichols, N., Kwon, Y., Yuan, Y., Xie, Z., Kang, S., Gil, B., Wang, C., Mou, T., Lin, H., Nian, Y., Chang, Q., Experimental trends and theoretical descriptors for electrochemical reduction of carbon dioxide to formate over Sn-based bimetallic catalysts. Journal of Materials Chemistry A, 2024, 12, 23560-23569.

5) Mou, T., Han, X. (co-first author), Zhu, H., Xin, H., Machine learning of lateral adsorbate interactions in surface reaction kinetics. Current Opinion in Chemical Engineering, 2022, 36, 100825.

6) Han, X., Mou, T., Liu, S., Ji, M., Gao, Q., He, Q., Xin, H. and Zhu, H., Heterostructured Bi-Cu2S nanocrystals for efficient CO2 electroreduction to formate. Nanoscale Horizons, 2022, 7, 508-514. (Outside Front Cover)

7) Han, X., Gao, Q., Yan, Z., Ji, M., Long, C., Zhu, H., Electrocatalysis in confined spaces: interplay between well-defined materials and the microenvironment. Nanoscale, 2021,13, 1515-1528.

8) Peng, H., Zhang, X., Han, X., You, X., Lin, S., Chen, H., Dai, S., Catalysts in coronas: a surface spatial confinement strategy for high-performance catalysts in methane dry reforming. ACS Catalysis, 2019, 9(10), 9072-9080. (Cover)

ORAL PRESENTATIONS

06.2025 Han. X., Chen, J-G., “Theoretical Prediction and Experimental Verification of IrOx Sup-ported on Titanium Nitride for Acidic Oxygen Evolution Reaction”, The 29th North American Catalysis Society Meeting, Atlanta, GA

06.2023 Han. X., Mou, T., Xin, H, Zhu, H., “Heterostructured Bi-Cu2S Nanocrystals for Efficient CO2 Electroreduction”, The 28th North American Catalysis Society Meeting, Providence, RI

11.2022 Han. X., Mou, T., Xin, H, Zhu, H., “Heterostructured Bi-Cu2S Nanocrystals for Efficient CO2 Electroreduction”, Annual meeting of the American Institute of Chemical Engineers (AIChE), Phoenix, AZ

05.2022 Han. X., Zhu, H., “Microphone Structured Bismuth/Cuprasulfide Promoting Electrochemical Reduction of CO2 to Formate”, The 27th North American Catalysis Society Meeting, New York, NY

11.2021 Han. X., Zhu, H., “Microphone Structured Bismuth/Cuprasulfide Promoting Electrochemical Reduction of CO2 to Formate”, Annual meeting of the American Institute of Chemical Engineers (AIChE), Boston, MA