(357au) Towards a More Sustainable Chemical Process Industry: Rational Design of Catalysts with Process Intensified Technologies for Applications in Heterogeneous Catalysis

Heterogeneous catalysis plays a crucial role in the development of sustainable, economical, and environment-friendly processes in the chemical industry. However, despite a long history in catalysis, these catalysts are designed mostly via lengthy and costly trial and error methods. Therefore, there is an increase in interest in the rational design of these catalysts to improve their catalytic performance. This objective of rational catalyst design can be combined with innovative technologies and process intensification principles to achieve drastic improvements in existing operations. Specifically, my research focuses on applying this approach systematically across the many length scales that govern chemical processes. At the nanoscale, we are developing a fundamental understanding of metal nanoparticle-support interactions for designing functional nanomaterials. At the mesoscale, we are using novel forms of energy i.e., microwave energy in zeolite-based catalysts for optimizing heat transport processes. Whereas, at the macroscale, we are designing energy and resource-efficient reactor configuration for zeolite synthesis.

Metal nanoparticle - support interactions.

Metal nanoparticles play an important role in advanced industries and technologies from electronics and pharmaceuticals to catalysts and sensors. A critical challenge in the use of these nanoparticles is their loss of functionality via particle coarsening, thus degrading their performance. Towards this end, in this collaborative project, we developed a novel method to measure the adhesion energy between metal nanoparticles and their supports, a crucial descriptor for their stability. We are further in the process of developing property-function relationships which would enable the rational design of nanocatalysts to tune adhesion, and thus control the rate of particle coarsening. Ultimately, more stable nanoparticles will lead to significant advances in human and environmental health, clean energy, and more efficient manufacturing.

Design of microwave-sensitive catalysts for methane upgrading to higher-value chemicals.

Microwave-assisted catalysis offers great promise as an intensified technology for chemical processing since energy is delivered directly to the active site. However, due to their complexity, it is poorly understood to date and no design criterion for microwave-sensitive catalysts exists. In this research, we set out to systematically explore how microwave radiation interacts with catalytic materials in order to guide the development of a microwave-sensitive catalyst. The work is focused on zeolite catalysts for application in methane upgrading via non-oxidative dehydro-aromatization. Such an intentional design of catalysts for microwave-assisted heterogeneous catalysis can be expected to enable taking full advantage of this promising microwave reactor concept.

Transitioning zeolite synthesis from batch to continuous

The transition of chemical synthesis processes from batch to continuous operation offers the prospect of strong improvements in energy intensity, capital cost, and physical footprint. In this study, we applied process intensification principles leading to a decrease in zeolite crystallization time from typically >24 hrs. in batch synthesis to ~1 min in continuous operation, i.e., improving the space-time yield of ZSM-5 by three orders of magnitude. Furthermore, a continuous mode of operation offers easier scale-up and improved operational flexibility for zeolite synthesis.

Overall, our overarching goal throughout these projects is to combine a fundamental understanding of rational catalyst design and intensified process technologies to achieve strong performance improvements in applications of heterogeneous catalytic processes. Through the course of my Ph.D. research, I have developed technical expertise in catalyst synthesis (nanocatalyst and zeolite synthesis) and characterization (electron microscopy, Energy-dispersive X-ray spectroscopy, X-Ray diffraction, X-ray photoelectron spectroscopy, BET surface area analysis, infrared spectroscopy), gas chromatography, mass spectrometry, and thermo-gravimetric analysis. I have also acquired skills in maintaining, troubleshooting, and upgrading lab equipment which helped me further advance my problem-solving abilities. In addition to the technical skills, I also developed interpersonal skills by training, mentoring, and supervising junior students, working on collaborative projects with both academic and industry partners as well as actively participating in and organizing graduate student activities.

My Research Interests include Chemical reaction engineering; Heterogeneous catalysis; Microwave catalysis; Catalyst synthesis and characterization; Zeolites or other mesoporous and microporous materials; Supported-metal nanoparticle catalysts or other nanomaterials and Process intensification.