(2im) Toward a More Sustainable World with Heterogeneous Photocatalysis: From Bench to Industry

Heterogeneous catalytic processes account for an annual production of trillions of dollars of value-added chemicals and products. However, their frequent demand for energy-intensive conditions, even with the use of current catalysts, establishes the chemical sector as one of the largest industrial energy consumers globally, with annual CO₂ emissions near the gigaton level. Heterogeneous photocatalysis with optically active metal nanoparticles that supports collective electronic resonance (Plasmon) is an emerging paradigm that has created exciting opportunities for developing more sustainable alternatives to the traditional petroleum-based thermal catalysis approaches. Strong light-matter interactions creates a local environment on the nanoparticle surface that facilitates chemical bond activations, enabling otherwise energetically unfavorable chemical reactions to proceed with high efficiencies and at milder operating conditions than those typify conventional catalysts. Photocatalysis with this approach shows promise for overcoming the energy demands of traditional thermal catalysis and unlocking new reactivity channels with higher reactivity and selectivity that cannot be accessed only by thermal means.

This work summarize our recent advances in developing tailored visible-light activated plasmonic photocatalysts for driving several environmentally and industrially relevant high-value reactions, including mitigation of anthropogenic compounds, such as CO₂ and CFCs, and production of clean fuel and fertilizer (H₂, NH₃) along with the mechanistic understanding of the processes by which illumination can give rise to chemical reactivity and modify the reaction pathways on plasmonic nanoparticle surfaces via controlling the elementary step energetics. Our efforts toward commercializing this technology and addressing challenges lay ahead (materials, scalability, photon management, process development, etc.) will also be discussed. Toward this goal, we are pioneering state-of-art electrified high-throughput photoreactor platforms that use light-emitting diodes (LEDs) to power chemical reactions for producing fuels and major commodity chemicals on an industrially relevant scale at low costs and zero carbon emission. Electrified photocatalysis, ideally fueled by renewable electricity, presents a feasible and sustainable route for replacing heat from fossil fuels with photons from LEDs in practical applications. LED technologies are experiencing a step-change in their efficiency and stability, providing a highly efficient yet cheap and reliable photon source across the visible spectrum. This and a continuous decline in the cost of renewable energies could establish the foundation for the electrified photocatalysis to potentially turn into a transformative technology to revolutionize the future of the energy and chemical industries once technological barriers are overcome. A transition from fossil-based burners in thermal plants to electrified photocatalysis for clean chemical manufacturing while reducing the energy cost also represents a significant leap toward decarbonizing chemical sectors with a substantial economic implication, in line with sustainability development goals determined by the United Nations.

Research Interests

My research has been driven by a central goal of exploring nanomaterials engineering and nanophotonic research for sustainable visible light-driven catalysis of industrially, energetically, and environmentally important reactions together with mechanistic study of light-driven chemistry. Additionally, I focused on studying catalysis with supported atomically dispersed species and exploring unusual metal-support interactions for controlling active sites to correlate atomic-scale structures to macroscale functionalities. Motivated by bringing sustainability to chemical and energy industry, I have been also contributing to technology development for electrified photocatalysis on an industrial relevant scale through developing one-of-a kind photoreactor platforms that use photons from LEDs, ideally fueled by renewable electricity, instead of heat from fossil fuels to power chemical reaction for fuel and commodity chemical productions. Once realized, this technology can revolutionize the global energy landscape and chemical industries by reducing energy usage, cost, and carbon emission.

In the future, I seek to build an inclusive, interdisciplinary, and dynamic research program that will integrate principles from chemistry and materials with advances in the design and atomic-level material engineering to create innovative photo-, magneto-, and electro-catalytic platforms for sustainable chemical transformations. The Robatjazi lab will investigate the basic and applied science of catalysis with those materials to further uncover the role of light, magnetic and electric fields on chemical reactivity at heterogeneous interfaces and exert control over the reaction dynamics by unconventional means. Toward this goal, we will develop operando spectroscopy and microscopy tools and design new reactors to build a comprehensive atomic-level understanding of chemical kinetics and reaction mechanisms in order to determine the structure-activity relationships of our catalysts. We will build upon a combination of my diverse academic training, the knowledge and expertise gained from conducting fundamental academic research as well as industry-level applied research and development, my passion for exploring new frontiers, and my mentoring and collaboration skills. My background uniquely positions me to propose novel approaches for developing next-generation catalytic platforms to address grand challenges in catalysis, environment, and global energy sustainability. My lab will bring together a vibrant and diverse team driven by the common goal of using our science to help humanity.

Keywords: Heterogeneous photocatalysis, plasmonics, electrochemistry, material engineering, clean fuel and energy, sustainability.

Teaching interests

I believe that excellent teaching and mentorship are vital to train the next generation of students, researchers, and science leaders in STEM. Based on extensive experiences, my teaching philosophy stands for providing students with a holistic learning experience for scientific and personal developments, both in the context of classrooms and my research group. My multidisciplinary training makes me well equipped to teach the existing undergraduate and graduate level courses in chemistry, heterogeneous catalysis, materials, nanophotonics, solar energy conversion spectroscopy, and electrochemistry topics. I am also keen to develop advanced courseworks bridging concepts in those topics. Examples include:

Heterogeneous catalysis and photocatalysis (graduate level): This course aims to provide an understanding of fundamental topics in catalysis, such as surface phenomena, reaction kinetics, scaling relationships, metal-support interactions, and the link between the thermodynamics and kinetics of elementary surface processes and reactivities, etc. The course also discusses nanophotonics principles and detailed insights of light-matter interactions for promoting catalysis on optically active metal nanoparticles, rational design of functional (photo)catalysts with tailored functionalities and methods for their advanced characterizations.

Sustainable energy production and storage (graduate and undergraduate level): This course aims to provide an understanding of photovoltaic and photoelectrochemical systems for renewable solar-energy generation. It will review fundamental principles of semiconductor- and photonics-based devices for the conversion of solar energy into electricity and artificial photosynthesis for green fuel production. Various topics will be discussed, including the design of thin-film light-absorbers, charge carrier dynamics in devices, their limitations, and characterization methods, and the design and discovery of state-of-art material systems for solar energy conversion.

Nanomaterials for energy (Undergraduate level): This course aims to provide a holistic overview of the growth, fabrication, and molecular-level modifications of a range of essential nanomaterial systems and their characterizations with emphasis on energy applications. In addition to lectures, this course will be consisted of several lab sections to provide hand-on experiments for synthesis and basic characterizations of simple nanomaterial systems for energy-related applications. This course will be specifically designed to provide an excellent opportunity for undergraduate students to stimulate their research curiosity, interests, and intellectual creativity.

My role as an educator extends far beyond the classroom, and as a principal investigator, the success of the students and researchers I mentor will be paramount. Students in my lab will be trained with the technical, analytical, and communication skills to succeed in their future careers.