Speaker: Nursaya Zhumabay

Title: Comparison of Rh and Pt catalysts for photoelectrocatalytic water splitting

Abstract

PEC water splitting for solar fuel production is one of the most promising artificial photosynthesis approaches.               

Noble metal particles (Rh, Pt, Pd, Ir) coated with a thin layer of Cr₂O₃ to form a core/shell structure are excellent cocatalysts for the (Ga_1-xZn_x)(N_1-xO_x) system.¹

In the current study to compare Rh and Pt cocatalysts, SrTiO₃ was chosen as a photocatalyst.² From comparison SrTiO₃/Rh catalyst shows better photocatalytic HER and OWS activity than SrTiO₃/Pt catalysts. However, it is known that Pt itself is the best electrocatalyst for HER. We hypothesize that the improved photocatalytic activity of Rh over Pt is related to the difference in band alignments of Rh and Pt with the Fermi level of the photocatalytic semiconductor.³

References

1. M.Yoshida, K.Takanabe, K.Maeda, A.Ishikawa, J.Kubota, Y.Sakata, Y.Ikezawa and K.Domen, J.Phys.Chem.C,2009,113,10151—10157.
2.  K.Domen, S.Naito, M.Soma, T.Onishi and K.Tamaru, J.Chem.Soc.,Chem.Commun.,1980,543—544;
3. M.Yoshida, A.Yamakata, K.Takanabe, J.Kubota, M.Osawa and K.Domen, J.Am.Chem.Soc.,2009,131,13218

Bio

Nursaya is currently in her 4th year of Ms/Ph.D. program under the supervision of Professor Magnus Rueping at KAUST Catalysis Center. In 2018, she completed her BSc in Chemical Engineering from Al-Farabi Kazakh National University in Kazakhstan. Her Ph.D. research focuses on the study of overall water splitting and hydrogen evolution reactions via electrochemical, photoelectrochemical and spectroelectrochemical techniques.

Speaker: Edwin Guevara

Title: Heavy Fuel Oil Surrogate Formulation Based on FT-ICR MS

Abstract

Generally, surrogate molecules are used to represent complex mixtures for property predictions and kinetic development. The aim of surrogate formulation is to replicate chemical and physical properties of a complex matrix using single or multiple molecules. However, creating surrogate formulations for heavy fuel oils requires using expensive, time-consuming, and hard to interpret chemical analytical techniques. This study presents a novel methodology for heavy fuel oil surrogate formulation based only on high-resolution mass spectrometry. The methodology was tested in a heavy fuel oil and a vacuum residue oil from the region. The results shows that surrogate molecules generated through this methodology agree with functional groups estimated by NMR and can predict some physical properties of the oils via quantitative structural property calculations. This study is expected to facilitate the estimation of surrogate molecules by making the process semi-automatic, without the need for multiple analytical techniques, reducing time, costs and subjectivity associated with conventional approaches. 

Bio

Edwin Guevara is a chemist graduated from the National University of Colombia. He obtained his master’s degree in petroleum engineering from the University of Los Andes and has more than ten years of experience working as a support engineer for one of Agilent Technologies’ subsidiarie in Colombia and Research assistant in the Department of Chemistry at the University of Los Andes.

Currently, Edwin is a PhD candidate at KAUST under the supervision of Professor Mani Sarathy. His research focuses on the development of advanced carbon materials from waste oil fractions with aim of expanding the use of petroleum beyond fuel production. 

Speaker: Serik Zhumagazy

Title: Selective Mono-Defluorinative Cross-Coupling of Trifluoromethyl arenes and Styrenes via Multiphoton Photoredox Catalysis

Abstract

Jiaqi Jia‡, Serik Zhumagazy‡, Chen Zhu, Salman Alsharif, Huifeng Yue* and Magnus Rueping*  

KAUST Catalysis Center, KCC, King Abdullah University of Science and Technology, KAUST, Thuwal 23955-6900, Saudi Arabia.

Organofluorines represent one of the most important classes of organic compounds which have wide application in the fields of pharmaceutical, chemical biology, and material science.1-6  The presence of fluorine atoms in molecules can significantly modulate the chemical and biological properties such as metabolic stability, lipophilicity, and bioavailability without bringing about significant alterations to their existing framework.7-10  As such, fluorine chemistry has developed into an important branch of organic synthesis, and the methods to access such compounds are always in high demand.

An unprecedented cross-coupling of trifluoromethyl arenes and styrenes has been realized via multiphoton photoredox catalysis. The trifluoromethyl arenes could undergo selective mono-defluorinative alkylation under mild reaction conditions, providing access to a series of valuable α, α-difluorobenzylic compounds. The reaction shows broad substrate scope and general functional group tolerance. In addition to the electron-deficient trifluoromethyl arenes that are easily reduced to the corresponding radical anion, the challenging electron-rich substrates were also successfully applied.

Bio

Serik received his Bachelor’s degree in Chemical Engineering from Al-Farabi Kazakh National University in Almaty, Kazakhstan. In 2019, he joined Professor Magnus Rueping’s research group to pursue doctoral degree. As part of his PhD studies, Serik’s research work is dedicated to exploring the application of transition-metal catalysis, photoredox catalysis, and electrochemistry in the context of cross-coupling reactions.