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SUMMARY:Prof. Boon Siang Yeo : Electrosynthesis of long-chain hydrocarbons
DTSTART:20260907T141500
DTEND:20260907T151500
DTSTAMP:20260922T133023Z
UID:2f0e45bedd9173dce8db6a417fe3e3ba4450e6a529710f9529c3ed02
CATEGORIES:Conferences - Seminars
DESCRIPTION:Prof. Boon Siang Yeo\,\nNational University of Singapore\,\nSi
 ngapore\nAbstract : In this presentation\, we share our works related to 
 the development of catalysts and discovery of the mechanisms for the elect
 roreduction of CO2 and CO to long-chain hydrocarbons. In particular\, we s
 hall show how C1-C6 alkanes and alkenes such as n-hexane could be selectiv
 ely formed. The catalysts that were found to work well were unexpectedly b
 ased on polarized nickel and cobalt\, rather than copper (which is general
 ly known to reduce CO2 to C1-C3 molecules). We reveal how we probe both th
 e identities of the catalytic sites and mechanistic pathways by which hydr
 ocarbon products were formed by using spectroscopy\, probe molecules and d
 ensity functional theory calculations. In particular\, we show how the sel
 ectivities of the products\, such as their linear / branching ratios\, cou
 ld be controlled by using pulsed electrolysis.  \nWhile it is possible to
  break the limitations of copper catalysts by using nickel- or cobalt- bas
 ed materials\, the ability of the latter to selectively generate hydrocarb
 ons is highly limited by the competing water reduction to H2 gas. We shall
  present a strategy to suppress H2 formation and enhance hydrocarbon forma
 tion during CO2 reduction by tuning the proton activity of proton donors d
 issolved in an aprotic dimethyl sulfoxide (DMSO) electrolyte. Across this 
 donor series\, the selectivity of hydrocarbons exhibits a volcano-shape de
 pendence on the acidity of the proton donors. The Faradaic efficiency of C
 1-C6 hydrocarbon increases from 4 % in aqueous 0.1 M KHCO3 electrolyte to 
 22.1 % in DMSO electrolyte spiked with 0.2 M ethylene glycol (EG). Nuclear
  magnetic resonance (NMR) spectroscopy shows that\, at 0.2 M\, EG preferen
 tially forms DMSO-EG hydrogen bonds that inhibit EG-EG clustering\, thereb
 y maintaining a well-dispersed proton donor environment. This solvation st
 ructure establishes a moderate proton-activity regime that facilitates CO2
  activation and C–C chain growth\, while suppressing H2 formation. Colle
 ctively\, our results reveal that tuning both the molecular structure of t
 he proton donor and its concentration-dependent solvation behavior in DMSO
  provides a strategy to delineate and access the proton-activity window th
 at maximizes CO2-to-hydrocarbon conversion.\n\nBio : Prof. Boon Siang Yeo
  studied chemistry at the National University of Singapore (NUS)\, where h
 e received his B.Sc. (1st class Honors) and M.Sc. degrees. He obtained his
  Ph.D. in chemistry from the ETH Zurich in 2009\, and then did his postdoc
 toral research at the Lawrence Berkeley National Laboratory. Boon Siang jo
 ined the Department of Chemistry\, NUS in 2012. His research interests lie
 s in developing electrocatalysts and processes for converting carbon dioxi
 de (CO2) into valuable multi-carbon chemicals and fuels like ethanol\, pro
 panol and long-chain hydrocarbons. The ultimate goal of his group’s work
  is to create commercially viable\, environmentally friendly methods for c
 arbon recycling and the production of industrial feedstocks and fuels\, he
 lping to build a sustainable energy economy. Boon Siang is a recipient of 
 the Dean’s Chair (2021-2024) and multiple teaching excellence awards (20
 14\, 2015\, 2016\, 2020) in the NUS. He currently serving as the Deputy He
 ad of the Department\, in charge of education.
LOCATION:Tseuzier https://plan.epfl.ch/?room==I17%204%20K2 https://epfl.zo
 om.us/j/65378030944
STATUS:CONFIRMED
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