(4oi) Insight into Selectivity of (photo)Catalytic Reactions

Fascinated by how nature can directly transfer solar energy into a chemical reaction, Tien Le applied ab initio Density Functional Theory (DFT) to investigate photo-driven reactions to design new generation of photocatalyst. Although several studies on the photocatalyst have been performed and hoped to imitate nature’s process to achieve similar conversion, the ultralow efficiencies of the photocatalyst unfortunately largely remained. Plasmonic catalyst based on the local surface plasmon resonance of noble metal nanoparticles is then investigated to increase the utilization of the visible wavelength and tailor the reaction selectivity toward a more sustainable future. In this process, plasmonic nanostructures are leveraged to harvest photonic energy, which triggers an energy and/or charge transfer to a catalytic active site where the reactions can take place. However, insights into the mechanisms of excited electrons can shift the selectivity remain elusive, particularly regarding the roles of structural defects, surface coverages and their interplay with the non-equilibrium charge carriers. Using CO2 conversion as the probe, she found that the non-equilibrium does not change much the intrinsic activation energy of CO2 dissociation on Cu2O pristine surface at the excited state compared to the ground state. In contrast, if the oxygen vacancies are introduced, the intrinsic barrier could be reduced at the ground state, and this remaining barrier could be further eliminated at the excited because of the non-equilibrium electrons. By employing the hydrogenation of phenylacetylene as a model transformation, she provided the insight of how employe visible-light irradiation can change the reaction selectivity, steering the reaction pathway from hydrogenation to homocoupling. Particularly, the role of surface coverage under the illumination condition is highlighted in controlling the reaction selectivity, i.e., the decrease in the concentration of H species at the surface, leading to plasmon- enhanced H2 desorption and promote the homocoupling pathway. Her calculations also suggest that the H-bonds between solvents and molecules can inhibit or promote the charge transfer process due to the shift of the frontier orbitals. The findings could be valuable for hybrid plasmonic catalyst design for sustainable energy and chemical transformation.

Teaching Interests

With her unique working experiences both industrial and academic area, her teaching interests include Chemical Engineering Fundamental, Process Design and Safety, Thermodynamics and Kinetics.