(2o) Fundamental Catalytic Reaction Design for Sustainable and Green Chemical Engineering

From the creation of synthetic fertilizers that helped feed the world to the invention of innovative materials used in various applications, chemical engineering has contributed to the transformation of society and individual lives during the past century. However, owing to the overuse of fossil fuels and inevitable environmental pollution from the industrial processes, the role of current chemical engineering has to be evolved into designing green chemical manufacturing to protect the environment and ecosystems. Innovative and interdisciplinary approaches grounded in fundamental scientific understanding can aid the development of sustainable chemical engineering. Atomic-scale design of novel catalysts and fundamental catalytic understanding combined with machine learning are required for material discovery toward efficient catalytic reactions. Upgrading the green synthesis of chemicals and fuels via renewable energy and electrocatalysis is critical to reshaping the traditional chemical process.

The availability of renewable energy sources (solar and wind) provides opportunities to replace many traditional chemical reactions with electrochemical processes to achieve industrial upgrading. For example, ethanol produced from agriculture feedstocks can work as a green and sustainable fuel in direct ethanol fuel cells (DEFCs) used for electric vehicles. To acquire the highest energy efficiency, ethanol needs to be completely oxidized to CO₂ via the twelve-electron transfer, rather than forming acetic acid as a common product through the four-electron transfer. During my Ph.D. work, the decoration effect of single Ir atomic layers on Pt(100) surface was evidenced to strongly adsorb the *CxHyO/CxHy reaction intermediates and to promote the CO oxidation from the catalyst surface. In order to fully oxidize ethanol to CO₂ and maximize the use of precious metals, unalloyed single atomic, partially oxidized Rh was deposited on the Pt nanocube surface to completely oxidize ethanol to CO₂ at a record-low potential of 0.35 V. The effect of the reversible configuration of Rh-O and C-Rh-O bonds during the reaction was demonstrated via in situ surface characterization. For the green synthesis of chemicals, the novel catalyst design strategy for on-site producing H₂O₂ from the two-electron oxygen reduction reaction was developed. The special Pd-O-C coordination between oxidized carbon nanotubes and clusters of three to four partially oxidized Pd atoms optimized its binding energy of key intermediate and thus enhanced the H₂O₂ production rate. The other possible way to control the reaction performance at the electrode interface is by modifying catalysts with specific functional groups of different polymeric binders in the electrode fabrication process. Combined with theoretical calculations, the mechanistic study of hydrophilic and hydrophobic polymeric binders was performed, which provided a relatively simple and promising methodology to tune the product selectivity from the electrochemical CO₂ reduction reaction.

Future plans for my independent research group will not only continue atomic-scale design of novel catalysts and fundamental mechanistic understanding of catalytic reactions, but also use hybrid technologies to invent sustainable chemical production processes, including machine learning, electrochemical react device design, reaction process optimization/reagent activation coupled with different methodologies. Projects will focus on coupling machine learning with experimental study to develop a fundamental understanding of descriptors for catalyst design toward various catalytic reactions and guide an efficient material discovery. In situ X-ray and infrared characterizations will be employed to study the surface reaction intermediates and catalyst evolution during the reaction. Electrochemical devices and reaction process optimization together with reagent activation will be explored in fertilizer production, CO₂ capture, storage and utilization, and alkane activation.

Teaching Interests

As a faculty, my goal is to train students to take ownership of their education and develop critical and creative thinking skills. Methodologies for achieving this objective include student-driven learning through the feedback-loop method in the class to learn “how to do it” rather than “what to do” based on systematic questioning and active feedback, group work to develop communication and collaborative skills for their future career, project-based tasks with toolbox teaching mechanism to train the student ability to solve problems independently and learn how to apply theory to obtain scientific understanding toward chemical engineering. These teaching methodologies have been obtained during my teaching activities: training over 20 students from underrepresented groups in a rural primary school as a volunteer teacher, working as a teaching assistant for undergraduate and graduate-level courses and mentoring undergraduate and graduate students in the laboratory for their research projects.

I would be excited to teach courses in heat transfer, mass transfer, and chemical reaction engineering. I will be interested to develop new courses including 1) Electrochemical and electrocatalysis focusing on different electrochemical applications under study including fuel cells, CO₂ conversion, chemical production via renewable energy, reactor design, and catalytic challenges for accelerating the industrial of these processes; 2) Principles of catalyst design with applications covering the current challenges and opportunities in various applications focused on the science of the preparation, characterization, and evaluation of catalysts as well as the recent progress in both academic and industrial fields; 3) Surface characterization for catalysts with an emphasis on the experimental examples and proposal writing. Given the significance of communication in the advancement of science, I would strive to integrate exercises that help students strengthen their written and oral communication abilities.