(4cu) Tracing the Fate of Active Centers in Engineered Catalytic Systems for Sustainable Energy Applications

Heterogeneous catalysis represents one of the most significant scientific contributions to the world, impacting a wide range of industries. From fuel production, pollution control, biomass conversion, and hydrogen production to ammonia synthesis and waste conversion, the applications of heterogeneous catalysis are vast. Consequently, there are ongoing efforts to enhance and comprehend the dynamic nature and active site evolution of these materials at both industrial and fundamental levels through experimental and computational research.^1,2 The structure-function relationship is central to catalytic performance, as it facilitates the synthesis of target sites for optimal reaction kinetics and thermodynamics. The synthesis of well-defined catalytic sites is crucial for goals such as: 1. maximizing metal utilization for critical materials (noble metals), 2. understanding the mechanism of catalyst deactivation, and 3. employing advanced spectroscopic and reactor design approaches for operando studies. Integrating conventional techniques with advanced computational tools can significantly enhance the catalysis community's ability to address emerging global challenges in sustainable energy.^3–5

The diverse research skills acquired during my academic journey in heterogeneous catalysis, expand from 1. catalyst synthesis and reactor studies for hydrotreating and supercritical water gasification, 2. computational catalysis, 3. spectroscopic studies (x-ray absorption (XAS), x-ray photoelectron (XPS) and infrared (IR) spectroscopy), and 4. electrocatalysis. As an independent research group, my team will work on the interface of thermal and electrocatalysis for sustainable energy applications such as advanced hydrocarbon conversion, hydrogen and ammonia production, and deriving value-added products from greenhouse gases. Leveraging my prior training, we will couple catalyst synthesis with reaction kinetics under operando conditions. Our goal is to advance operando catalyst characterization through spectroscopic techniques, and computational tools to quantitatively map active centers. Utilizing these techniques the objectives are to 1. understand the structure-function relationship to tune catalyst activity, selectivity and stability, 2. conduct operando and computational studies on catalytic site evolution under reaction conditions for ‘engineered catalyst design’, and 3. designing methods for advancing spectroscopic measurements within my lab and through collaborations with national labs. Overall, the group aims to achieve 'engineered catalyst designs for a sustainable future' by targeting specific structure-function properties.

Doctoral Research (University of California, Davis; Chemical Engineering; Advisors: Prof. Ambarish Kulkarni and Dr. Simon Bare (Stanford Linear Accelerator (SLAC))

My doctoral research was centered around combining atomistic simulations and x-ray absorption spectroscopy to distinctively understand the nature of the catalytic site with particular focus on well-defined catalysts like atomically dispersed catalysts on different supports. My graduate research, which encompassed computational calculations, beamtime experiments at SLAC, and catalyst synthesis in the Gates lab at UC Davis, provided an invaluable opportunity for learning and growth. A key achievement of my research was the development of an automated python-based workflow called QuantEXAFS.⁴ This workflow performs one-to-one mapping of experimental EXAFS spectra with models from a database of thousands of DFT-optimized structures. This innovation led to several collaborative projects during my graduate studies. In the final year of my Ph.D., I interned jointly in the Cargnello Lab at Stanford University and at the Stanford Synchrotron Radiation Lightsource (SSRL), where I worked on gold nanoparticles synthesis and tested their application for epoxidation reactions. During this time, I also had the opportunity to conduct several beamtime experiments as part of the Co-ACCESS team.

Postdoctoral Research (Massachusetts Institute of Technology; Chemical Engineering; Advisor: Prof. Yuriy Romàn-Leshkov)

As part of my postdoctoral research, I work as a part of the Center for Programmable Catalysis (CPEC). My project focuses on the intersection of thermal catalysis and electrocatalysis, studying the promotional effect of electric fields on hydrogenation reactions at the solid-gas interface. I use metal thin-film based capacitive devices (catalytic condensers) to reduce the energy barrier of the rate-determining step in the reaction mechanism. In addition to conducting reactor studies and kinetics in the Romàn lab, I employ various characterization techniques, including microscopy (atomic force (AFM) and scanning electron (SEM)) and operando spectroscopy (IR, XPS, XAS). Through these characterizations, we aim to understand the mechanisms of charge transfer, the stability of the active metal layer, and the structure-function relationship. As part of my postdoc work, I have also led proposal submissions for XAS beamtime at SLAC and ambient pressure x-ray photoelectron spectroscopy (AP-XPS) at Brookhaven National Lab (BNL).

Teaching Interests

Continuous acquisition of wisdom, sharing knowledge, and effective mentoring are the cornerstones of scientific progress. My major motivation for pursuing academia is the opportunity to always be surrounded by enthusiastic minds– eager to learn, and the profound impact efficient mentoring can have on students. This forms the core of my teaching philosophy– I aim to inspire future chemical engineers to be curious, to seek answers, and to develop solutions for the unanswered questions they encounter. My diverse background, spanning experimental to computational catalysis, equips me with the skills to understand various fundamental subjects in chemical engineering. While I am particularly inclined to teach thermodynamics or chemical reaction engineering, my prior experience has prepared me to teach any chemical engineering course. I have served as a teaching assistant for undergraduate thermodynamics and mass balance courses during my Ph.D. and M.S. programs. I particularly enjoyed developing Python-based modules and demonstrating them for the undergraduate thermodynamics class at UC Davis. I also had the opportunity to teach an invited lecture in graduate Kinetics class at UC Davis. For graduate teaching, I believe in a discussion-based model and incorporating subject-related guest lectures from experts to foster creative thinking, collaboration, and application-focused learning among students. Due to my interest in mentoring, I have participated in mentor-mentee relationship-building programs at UC Davis and have been involved in DEI-focused roles. I am committed to providing an inclusive space for learning and growth for students and individuals from all backgrounds and cultures. My group culture will focus on making science enjoyable, fostering great friendships and collaborations among group members, while seeking innovative and sustainable energy solutions for the world. Our core-values will be centered on democracy, equity, and opportunities for all curious minds.

A complete list of publications (google scholar)

Selected publications (*co-first authors)

(1) Rana, R.; Vila, F. D.; Kulkarni, A. R.; Bare, S. R. ACS Catal. 2022. 12 (22), 13813-13830.

(2) Shaw, W. J.; Kidder, M. K.; Bare, S. R.; Delferro, M.; Morris, J. R.; Toma, F. M.; Senanayake, S. D.; Autrey, T.; Biddinger, E. J.; Boettcher, S.; Bowden, M. E.; Britt, P. F.; Brown, R. C.; Bullock, R. M.; Chen, J. G.; Daniel, C.; Dorhout, P. K.; Efroymson, R. A.; Gaffney, K. J.; Gagliardi, L.; Harper, A. S.; Heldebrant, D. J.; Luca, O. R.; Lyubovsky, M.; Male, J. L.; Miller, D. J.; Prozorov, T.; Rallo, R.; Rana, R.; Rioux, R. M.; Sadow, A. D.; Schaidle, J. A.; Schulte, L. A.; Tarpeh, W. A.; Vlachos, D. G.; Vogt, B. D.; Weber, R. S.; Yang, J. Y.; Arenholz, E.; Helms, B. A.; Huang, W.; Jordahl, J. L.; Karakaya, C.; Kian, K.; Kothandaraman, J.; Lercher, J.; Liu, P.; Malhotra, D.; Mueller, K. T.; O’Brien, C. P.; Palomino, R. M.; Qi, L.; Rodriguez, J. A.; Rousseau, R.; Russell, J. C.; Sarazen, M. L.; Sholl, D. S.; Smith, E. A.; Stevens, M. B.; Surendranath, Y.; Tassone, C. J.; Tran, B.; Tumas, W.; Walton, K. S. Nat. Rev. Chem. 2024, 8 (5), 376–400.

(3) Chen, Y.*; Rana, R.*; Huang, Z.; Vila, F. D.; Sours, T.; Perez-Aguilar, J. E.; Zhao, X.; Hong, J.; Ho, A. S.; Li, X.; Shang, C.; Blum, T.; Zeng, J.; Chi, M.; Salmeron, M.; Kronawitter, C. X.; Bare, S. R.; Kulkarni, A. R.; Gates, B. C. J. Phys. Chem. Lett. 2022.

(4) Chen, Y.*; Rana, R.*; Sours, T.; Vila, F. D.; Cao, S.; Blum, T.; Hong, J.; Hoffman, A. S.; Fang, C. Y.; Huang, Z.; Shang, C.; Wang, C.; Zeng, J.; Chi, M.; Kronawitter, C. X.; Bare, S. R.; Gates, B. C.; Kulkarni, A. R. J. Am. Chem. Soc. 2021, 143 (48), 20144–20156.

(5) Chen, Y.*; Rana, R.*; Zhang, Y.; Hoffman, A. S.; Huang, Z.; Yang, B.; Vila, F. D.; Perez-Aguilar, J. E.; Hong, J.; Li, X.; Zeng, J.; Chi, M.; Kronawitter, C. X.; Wang, H.; Bare, S. R.; Kulkarni, A. R.; Gates, B. C. Chem. Sci. 2024, 6454–6464.