The Chemical and Biological Engineering Department is pleased to present student seminars by [student name] and [student name] as part of our ChBE Seminar Series.

Camila Kofman will present a seminar titled "From Sequence to Function: RNA engineering towards elucidating ribosome design rules."

ABSTRACT: The ribosome is a highly complex macromolecular machine that plays a crucial role in protein synthesis. Rapidly catalyzing the formation of peptide bonds between amino acids in a sequence-defined manner, it exhibits an impressively low error rate of less than 0.01%. The ability to engineer the ribosome for novel functions has the potential to enable advances in medicine and materials, as well as help elucidate the intricacies of molecular translation. However, engineering the ribosome is challenging due to its sequence and structural complexity as well as its essential role in maintaining life. Towards this goal, I have employed novel methods to probe the flexibility of the ribosomal active site and identify mutants with improved functionality. These findings advance basic understanding of ribosome function and translation, as well as help map the mutational landscape of the ribosome to aid in the development of modified ribosomes and specialized strains for synthetic biology.

Brianna Ruggiero will present a seminar titled "Exploring the relationship between bulk and local reaction environments for electrocatalytic oxygen reduction to hydrogen peroxide."

ABSTRACT:

The electrocatalytic oxygen reduction reaction (ORR) is a promising method for the sustainable production of hydrogen peroxide (H2O2), offering improved energy and resource efficiency vs. the conventional production route, but H2O2 activity and selectivity remain significant challenges. To address these issues, significant attention has focused on designing highly active and selective carbon-based catalysts which are promising based on their low cost, elemental abundance, excellent stability, and tunable physical properties. In addition to modifying material properties, the ORR is also strongly impacted by the local catalyst environment, which is controlled by bulk reactor properties (e.g. electrolyte ion composition, pH), operating conditions (e.g. electric potential, mass transport), and complex phenomena at the catalyst/electrolyte interface. While some local catalyst environment effects have been studied using model Pt electrocatalysts, these effects on other ORR catalysts, such as carbon-based materials, are not widely reported. It is crucial to improve our fundamental understanding of the relationships between catalyst material, electrolyte composition, and catalytic performance to further enhance overall H2O2 activity and selectivity.

In this talk, I will discuss strategies to enhance H2O2 electrosynthesis via catalyst design, reaction environment tuning, and electrochemical reactor development. To investigate the activity and selectivity of the ORR in different reaction environments, I employed a rotating ring disk electrode (RRDE) technique which precisely controls mass transport. Additionally, I modified the RRDE with a pH sensing material to monitor local pH changes near the catalyst surface during operation, which provided critical insights to understand ORR performance trends. I found that electrolyte cations impact the magnitude of local pH changes and therefore play an important role in modifying ORR performance. Aside from tuning the reaction environment, I successfully synthesized a series of boron and nitrogen co-doped carbon catalysts that achieve high H2O2 performance under neutral pH conditions, compared to most H2O2 catalysts which operate in strong base. These catalysts were further evaluated in a gas diffusion electrode electrochemical flow cell to assess their practical viability and potential for real-world applications. By tuning the catalyst properties and reaction environment, I achieved selective H2O2 production at industrially-relevant rates and concentrations. This work improves our understanding of the origin of H2O2 selectivity, providing valuable insights for the design and optimization of electrochemical systems for various applications, including energy conversion, water treatment, and chemical synthesis.

Bagels and coffee will be provided at 9:30am, and the seminar will start at 9:40am. Please plan to arrive on time to grab a bagel and mingle!

*Please note that there will be no Zoom option for seminars this year.