Student(s): Alexandra Tsarenkov
Project: Understanding the Role of Platinum and Bismuth in Selective Alcohol Oxidation
Advisor(s): Steve McIntosh
Abstract
Bismuth has been observed to have a promotional effect on the catalytic properties of platinum, particularly in the selective oxidation of alcohols. Used together, they significantly enhance the catalytic activity of benzyl alcohol oxidation, producing industrially important products such as benzaldehyde and benzoic acid. Several mechanisms for this effect have been proposed. Among these are the ideas that the formation of a Pt/Bi alloy allows them to work synergistically, or that Bi inhibits the corrosion of Pt, enhancing its catalytic stability. However, experimental data show these mechanisms are inconsistent. Herein, we present that the synergistic effect between Pt and Bi is supported by the Co-Operative Redox Enhancement (CORE) mechanism, which demonstrates synergistic redox coupling between two disparate metals by spontaneous polarization, using benzyl alcohol oxidation as a model reaction. This was investigated using a single chamber electrochemical cell, loaded with Bi2O3/C and Pt/C coated on carbon cloths as separate electrodes. The two electrodes used in tandem resulted in a substantial increase in the conversion of benzyl alcohol to benzaldehyde and benzoic acid. More importantly, a short-circuit current, accounting for 12.94.1 % of the total reaction conversion, was observed, strongly supporting the CORE mechanism. Stability tests showed that the Bi2O3/C and Pt/C mixture maintained CORE efficiency across 4 runs, while Pt/C alone showed more stable but generally lower conversion. The results of the experiments conducted strongly support that the Bi promotional effect on Pt is at least partially rooted in the CORE mechanism.
About Alexandra Tsarenkov
Major: Chemical and Biomolecular Engineering
Alexandra Tsarenkov is a junior studying chemical engineering. She has been conducting research in the McIntosh Lab for over a year as a Rossin Research Scholar. Alexandra hopes her research will help make essential chemical processes more efficient and environmentally sustainable. Alexandra presented her work at the American Institute of Chemical Engineers conference in October 2025 and was awarded second place in the Reaction and Catalysis Engineering poster competition. She is currently a Thermodynamics TA in Prof. Gartner’s class. After graduation, she hopes to continue working on sustainability goals within the chemical engineering industry. Alexandra grew up in Brooklyn, N.Y., and graduated from Stuyvesant High School in Manhattan. She attends Lehigh as part of the University’s Soaring Together Scholarship program. Outside of the lab, she enjoys spending time outdoors, hiking with her rescue dog, camping, and climbing.