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On 13 June, at VNUHCM–University of Science (HCMUS), doctoral researcher Trần Phương Dung, from the Theoretical and Physical Chemistry doctoral programme (2020 cohort), successfully defended a doctoral thesis entitled “A computational study of the oxygen reduction reaction on metalloporphyrin catalysts”. The research was supervised by Associate Professor Đỗ Ngọc Sơn (VNUHCM–University of Technology) and Associate Professor Phạm Trần Nguyên Nguyên (HCMUS).

During the viva, Trần Phương Dung presented key research findings regarding the catalytic activity of metalloporphyrin materials and heterogeneous metalloporphyrin catalysts supported on two-dimensional MoS₂ for the oxygen reduction reaction (ORR). The ORR represents a cornerstone reaction in energy conversion processes, particularly within the development of catalytic materials for fuel cells and clean energy systems.

To conduct the study, the doctoral researcher employed computational chemistry simulation methods based on density functional theory (DFT), combined with thermodynamic modelling. This approach enabled the investigation of electronic structure alterations, charge transfer processes, and the energetic mechanisms of reaction steps at the atomic level.

The thesis focuses on three primary research directions. Firstly, the study investigates the influence of functional groups (methyl, amino, and carboxyl) substituted at the meso position of the iron porphyrin ring. This investigation clarifies the role of these substituents in modulating charge distribution around the active iron (Fe) metal centre, alongside the subsequent impact on the catalytic activity of the material.

Secondly, the research evaluates the heterogeneous catalytic system MeTMP/MoS₂ (where Me = Fe, Co, Ni). Computational results indicate that the interaction between the porphyrin layer and the MoS₂ support medium can enhance catalytic properties. The cobalt-containing catalytic system was identified as possessing high potential for the ORR, owing to a capacity for reducing activation energy and suppressing the competing hydrogen evolution reaction (HER).

Thirdly, the thesis examines the impact of doping heteroatoms (B, P, S, Co) into the central region of the CoTMP/MoS₂ catalyst. The findings demonstrate that doping with certain elements, such as boron (B) and phosphorus (P), provides the capability to tune reaction energies, thereby contributing to enhanced selectivity of the catalytic material towards desired reaction pathways.

The outcomes of this thesis contribute valuable theoretical foundations to the study of reaction mechanisms on catalytic material surfaces via computational chemistry methods. Furthermore, the research offers significant insights to guide the design and development of metalloporphyrin-based oxygen reduction catalysts for applications within the clean energy sector.

The Examination Committee affirmed that the thesis rests upon a sound scientific foundation, employs appropriate research methodologies, and holds substantial reference value for subsequent studies in related fields. Consequently, the Committee recommended that Trần Phương Dung be awarded the degree of Doctor of Philosophy in Chemistry.