(6aw) Catalytic CO2 Conversion to Clean Fuels and Chemicals: Integration of Traditional Metallic Catalysts and Metal-Organic Frameworks

Satisfying the demand for efficient energy generation and sustainable chemical production via carbon resources while mitigating adverse environmental effects is a defining challenge of the 21^st century. Catalysis offers avenues to satisfy these demands by creating efficient and sustainable ways to produce chemicals using non-traditional carbon resources. My research primarily aims at developing efficient catalysts and adsorbents for clean energy applications. Both my doctoral and postdoctoral studies at Penn State focused on catalytic CO₂ conversion to cleans fuels and chemicals using bimetallic catalysts. My current postdoctoral research at Georgia Tech focuses on developing novel metal-organic framework (MOF) and carbon-based materials for efficient natural gas purification. Going forward, I envision incorporating MOFs materials with traditional metallic catalysts for sustainable value-added chemical synthesis from CO₂ hydrogenation.

As an important branch of Carbon Dioxide Capture, Utilization, and Storage (CCUS), catalytic CO₂ conversion for synthesizing chemical feedstocks and transportation fuels has recently attracted great attention worldwide. Major advances in energy-efficient catalytic CO₂ conversion using renewable energy could reduce both the greenhouse-gas emissions and dependence on non-renewable resources such as petroleum. The synthesis of oxygenates and hydrocarbons from CO₂ hydrogenation is one of the promising approaches for environmentally-friendly syntheses of sustainable chemical feedstocks and fuels. In my Ph.D. work and postdoctoral research at Penn State with Prof. Chunshan Song, I developed a selective, active, and stable Pd-Cu bimetallic catalyst for CO₂ hydrogenation to methanol, and systematically studied the composition-structure-catalytic performance relationship by combining activity tests, kinetic studies, and advanced characterization techniques, including X-ray and infrared spectroscopy. My research also advanced the fundamental understanding of alloy effects, key reaction intermediates, as well as plausible reaction pathways by incorporating both experimental results and theoretical calculations. Currently, I am expanding my research portfolio by working on ZIF-derived catalysts to address the challenge and opportunities involved with CO₂ hydrogenation to value-added hydrocarbons. Through my postdoctoral research at Georgia Tech with Prof. Krista Walton, I have designed carbon- and MOF-based adsorbents with tunable porosities and chemical functional groups for efficient natural gas purification. My most recent work introduced carbide-derived carbon (CDC) materials with tailorable porosity and metallic nanoparticles showing excellent synergetic effect for natural gas purification.

My future work aims to lead the development of novel catalysts by uniquely integrating traditional metallic sites with MOFs for catalytic CO₂ conversion to value-added fuels and chemicals, especially for higher-value alcohol syntheses, where the thermodynamic restraint is limited. These newly designed catalysts represent a class of novel catalysts with excellent tailorability comprising desired active centers, large accessible surface areas, and tunable porosity, as well as adjustable MOF/ZIF-metal site interaction. Design of these catalysts with desired features will be guided by fundamental understandings of adsorption property and structure-property-catalytic characteristic relationship, as well as metal-support interaction. The catalyst preparation method will include both “top-down” encapsulation and “bottom-up” impregnation strategies. With extensive experience in ZIF and MOF materials and strong expertise in catalyst preparation, testing, and characterization, I am uniquely suited to undertake these challenging research efforts. The research in novel MOF-derived catalysts will help to debottleneck current technological issues associated with catalytic CO₂ conversion, and enable the sustainable synthesis of value-added products, such as hydrocarbons and higher alcohols.

Teaching Interests:

I view teaching as an essential and enjoyable part of being a faculty member, so I am excited about the opportunity to lead both undergraduate- and graduate-level classes. As a post-doc at Penn State, I supervised graduate students in the CO₂-conversion project and contributed 3 publications already, and another 2 manuscripts in preparation. Furthermore, I have also served as both lecturer and teaching assistant for a graduate-level course since 2013. Drawing from my previous experiences working with students, I am excited to share my teaching and researching experiences with undergraduate students to help cultivate their interests for science, and contribute to the development of their educational paths. Courses I would particularly enjoy teaching include Chemical Reaction Engineering, Chemical Engineering Fundamentals, and Characterization of Catalytic Materials at both undergraduate and graduate levels. In addition, I also plan to develop a course introducing the fundamentals of catalysis, including reactor design, mass/heat transfer limitations, catalyst preparation and evaluation, and kinetic studies, as well as describing how state-of-the-art characterization techniques can be applied to gain insights into the structure-activity performance relationship and mechanistic study in heterogeneous catalysis.

Selected publications

1. Nie, X. Jiang, H. Wang, W. Luo, M. J. Janik, Y. Chen, X. Guo, C. Song, Mechanistic Understanding of Alloy Effect and Water Promotion for Pd-Cu Bimetallic Catalysts in CO₂ Hydrogenation to Methanol, ACS Catalysis, 8 (2018), 4873-4892. (considered as equal contribution).
2. Jiang, X. Wang, X. Nie, N. Koizumi, X. Guo, C. Song, CO₂ Hydrogenation to Methanol on Pd-Cu Bimetallic Catalysts: CO₂/H₂ Ratio Dependence and Surface Species, Catalysis Today, (2018), https://doi.org/10.1016/j.cattod.2018.02.055.
3. Li, X. Nie, X. Jiang, A. Zhang, F. Ding, M. Liu, Z. Liu, X. Guo, C. Song, ZrO₂ Support Imparts Superior Activity and Stability of Co Catalysts for CO₂ Methanation, Applied Catalysis B: Environmental. 220 (2017), 397-408.
4. Li, A. Zhang, X. Jiang, C. Chen, Z. Liu, C. Song, X. Guo, Low Temperature CO₂ Methanation: ZIF-67-Derived Co-Based Porous Carbon Catalysts with Controlled Crystal Morphology and Size, ACS Sustainable Chemistry & Engineering, 5 (2017), 7824-7831.
5. Jiang, N. Koizumi, X. Guo, C. Song, Bimetallic Pd-Cu Catalysts for Selective CO₂ Hydrogenation to Methanol, Applied Catalysis B: Environment. 170 (2015), 173-185.
6. Koizumi, X. Jiang, J. Kugai, C. Song, Effects of Mesoporous Silica Supports and Alkaline Promoters on Activity of Pd Catalysts in CO₂ Hydrogenation for Methanol Synthesis, Catalysis Today, 194 (2012), 16-24.