{"id":6102,"date":"2026-10-19T09:48:28","date_gmt":"2026-10-19T09:48:28","guid":{"rendered":"https:\/\/phd.hi.is\/doktorsvorn\/doktorsvorn-i-efnaverkfraedi-ebrahim-tayyebi\/"},"modified":"2026-10-19T09:48:28","modified_gmt":"2026-10-19T09:48:28","slug":"doktorsvorn-i-efnaverkfraedi-ebrahim-tayyebi","status":"publish","type":"phd_defence","link":"https:\/\/phd.hi.is\/en\/doktorsvorn\/doktorsvorn-i-efnaverkfraedi-ebrahim-tayyebi\/","title":{"rendered":"Doktorsv\u00f6rn \u00ed efnaverkfr\u00e6\u00f0i – Ebrahim Tayyebi"},"content":{"rendered":"
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V\u00f6rninni ver\u00f0ur streymt:\u00a0 <\/strong>https:\/\/livestream.com\/hi\/doktorsvornebrahimtayyebi<\/a><\/p>\n

Doktorsefni:<\/strong> Ebrahim Tayyebi<\/p>\n

Heiti ritger\u00f0ar:<\/strong> Rafefnafr\u00e6\u00f0ileg CO2 og N2 afoxun \u00e1 m\u00e1lmum og m\u00e1lmox\u00ed\u00f0um (Modeling electrochemical CO2 and N2 reduction reactions on transition metals and metal oxides)<\/p>\n

Andm\u00e6lendur:<\/strong> Dr. Anders Hellman, pr\u00f3fessor vi\u00f0 e\u00f0lisfr\u00e6\u00f0ideild Chalmers-t\u00e6knih\u00e1sk\u00f3la \u00ed Gautaborg, Sv\u00ed\u00fej\u00f3\u00f0
Dr. Lars C. Grabow, pr\u00f3fessor vi\u00f0 efnaverkfr\u00e6\u00f0ideild University of Houston \u00ed Texas, Bandar\u00edkjunum<\/p>\n

Lei\u00f0beinandi:<\/strong> Dr. Egill Sk\u00falason, pr\u00f3fessor vi\u00f0 I\u00f0na\u00f0arverkfr\u00e6\u00f0i-, v\u00e9laverkfr\u00e6\u00f0i- og t\u00f6lvunarfr\u00e6\u00f0ideild H\u00e1sk\u00f3la \u00cdslands<\/p>\n

Einnig \u00ed doktorsnefnd:<\/strong>
Dr. Hannes J\u00f3nsson, pr\u00f3fessor vi\u00f0 Raunv\u00edsindadeild H\u00e1sk\u00f3la \u00cdslands
Dr. Elvar \u00d6rn J\u00f3nsson, s\u00e9rfr\u00e6\u00f0ingur \u00e1 Raunv\u00edsindastofnun H\u00e1sk\u00f3lans <\/p>\n

Doktorsv\u00f6rn st\u00fdrir:<\/strong> Dr. R\u00fanar Unn\u00fe\u00f3rsson, pr\u00f3fessor og deildarforseti I\u00f0na\u00f0arverkfr\u00e6\u00f0i-, v\u00e9laverkfr\u00e6\u00f0i- og t\u00f6lvunarfr\u00e6\u00f0ideildar H\u00e1sk\u00f3la \u00cdslands<\/p>\n

\u00c1grip<\/strong>
Meginmarkmi\u00f0 \u00feessarar ritger\u00f0ar er notkun t\u00f6lvureikninga sem byggja \u00e1 \u00fe\u00e9ttifellafr\u00e6\u00f0i vi\u00f0 ranns\u00f3knir \u00e1 rafefnafr\u00e6\u00f0ilegri afoxun \u00e1 CO2 og N2. Stu\u00f0st er vi\u00f0 n\u00fdlegt l\u00edkan af rafefnafr\u00e6\u00f0ilegum samskeytum rafskauts og rafvaka sem gerir okkur kleyft a\u00f0 rannsaka hreyfifr\u00e6\u00f0i fyrrnefndra afoxunarhvarfa. Fyrst er einfalt varmafr\u00e6\u00f0ilegt l\u00edkan nota\u00f0 vi\u00f0 athuganir \u00e1 rafefnar\u00e6\u00f0ilegri CO2 afoxun \u00e1 12 hli\u00f0arm\u00e1lma-ox\u00ed\u00f0um. Notast er vi\u00f0 yfirbor\u00f0 r\u00fat\u00edl kristalbyggingarinnar til a\u00f0 kanna f\u00fdsileika CO2 afoxunar \u00e1 m\u00e1lmox\u00ed\u00f0a-hv\u00f6tum. Sk\u00f6lun bindiorku mismunandi milliefna er reiknu\u00f0 og notu\u00f0 til \u00feess a\u00f0 leggja fram vi\u00f0mi\u00f0 fyrir bindifr\u00edorku vetnis og h\u00fddrox\u00ed\u00f0s \u00e1 hv\u00f6tum sem s\u00fdna b\u00e6\u00f0i g\u00f3\u00f0a virkni og s\u00e9rt\u00e6kni vi\u00f0 afoxun CO2. \u00de\u00e6r ni\u00f0urst\u00f6\u00f0ur m\u00e1 \u00ed framhaldinu nota vi\u00f0 frekari \u00fer\u00f3un hvata fyrir rafefnafr\u00e6\u00f0ilega CO2 afoxun.
Til a\u00f0 \u00f6\u00f0last frekari inns\u00fdn \u00e1 afoxunarhvarfi CO2 \u00e1 hli\u00f0arm\u00e1lmsox\u00ed\u00f0um \u00fearf a\u00f0 framkv\u00e6ma n\u00e1kv\u00e6mari reikninga. Sl\u00edkir reikningar krefjast mikils t\u00f6lvut\u00edma svo framkv\u00e6md \u00feeirra fyrir \u00f6ll 12 hli\u00f0arm\u00e1lmsox\u00ed\u00f0in er ekki f\u00fdsileg fyrir eitt og sama doktorsverkefni\u00f0. \u00dear af lei\u00f0andi einbeittu menn s\u00e9r a\u00f0 RuO2(110) yfirbor\u00f0i. Framkv\u00e6mdar eru hermanir sem byggja \u00e1 grunnl\u00f6gm\u00e1lum n\u00e1tt\u00farunar til \u00feess a\u00f0 sp\u00e1 fyrir um hreyfifr\u00e6\u00f0i sameinda vi\u00f0 stofuhita, auk reikninga \u00e1 heildarorku kerfisins, til \u00feess a\u00f0 b\u00e6ta b\u00e6\u00f0i l\u00edkani\u00f0 og a\u00f0fer\u00f0afr\u00e6\u00f0ina sem notast hefur veri\u00f0 vi\u00f0 hinga\u00f0 til. \u00deessir reikningar varpa lj\u00f3si \u00e1 hvarfgang rafefnafr\u00e6\u00f0ilegrar CO2 afoxunar \u00e1 RuO2 me\u00f0 \u00fev\u00ed a\u00f0 kanna \u00e1hrif vatns \u00e1 hvarfi\u00f0, auk \u00feess sem rafefnafr\u00e6\u00f0ilegir virkjunarh\u00f3lar eru reikna\u00f0ir. H\u00e6gt er a\u00f0 \u00e1\u00e6tla hlutfallslegt magn mismunandi myndefna, svo sem metans, metn\u00f3ls, CO(g), mauras\u00fdru, metand\u00ed\u00f3ls og vetnis. Talsver\u00f0ur munur finnst \u00e1 virkjunarh\u00f3lum fyrir myndun metans og metan\u00f3ls \u00ed samr\u00e6mi vi\u00f0 tilraunir sem hafa s\u00fdnt metan\u00f3l myndun en ekki metan. Myndun og \u00f3bein \u00e1hrif CO sameindarinnar \u00ed CO2 afoxun er \u00fatsk\u00fdrt. Einnig finnst a\u00f0 vetni er meginmyndefni\u00f0 fyrir \u00e1lag\u00f0a spennu \u00e1 bilinu -0.2 V til -0.9 V, sem er \u00ed g\u00f3\u00f0u samr\u00e6mi vi\u00f0 n\u00fdlegar tilraunir. \u00c1\u00e6tlu\u00f0 yfirspenna fyrir myndun metan\u00f3ls er um -1 V. Reikningarnir s\u00fdna auk \u00feess hvers vegna RuO2 virkar sem hvati fyrir afoxun CO2 \u00ed mauras\u00fdru og CO(g) \u00ed snefilmagni, \u00ed samr\u00e6mi vi\u00f0 tilraunir.
Loks er athugu\u00f0 rafefnafr\u00e6\u00f0ileg myndun ammon\u00edaks \u00e1 Ru yfirbor\u00f0i. Notast er vi\u00f0 \u00fe\u00e9ttnifellafr\u00e6\u00f0ireikninga til a\u00f0 varpa lj\u00f3si \u00e1 hvarfgang niturafoxunar \u00e1 m\u00f3tum rafvaka og Ru(0001) rafskauts. Enginn virkjunarh\u00f3ll annar en varmafr\u00e6\u00f0ilegur fannst fyrir fyrsta pr\u00f3tonu-rafeinda flutnings skrefi\u00f0 \u00fear sem NNH millisameind myndast fr\u00e1 nitursameind, en \u00feetta skref er tali\u00f0 vera spennutakmarkandi fyrir afoxun niturs \u00e1 Ru(0001) yfirbor\u00f0i. Hvarfgangurinn sem sp\u00e1\u00f0 er fyrir afoxun niturs \u00e1 Ru(0001) er \u00fear sem nitursamdeindin sundrast ekki strax heldur afoxast sameindin \u00e1 yfirbor\u00f0inu \u00feanga\u00f0 til \u00ferj\u00fa pr\u00f3t\u00f3nu-rafeinda p\u00f6r hafa bundist \u00e1 ytra niturat\u00f3mi\u00f0. \u00de\u00e1 sundrast N-NH3 tengi\u00f0 og myndar fyrstu NH3 sameindina og nitur at\u00f3m ver\u00f0ur eftir \u00e1 yfirbor\u00f0inu og afoxa\u00f0 a\u00f0 lokum \u00ed amm\u00f3n\u00edak. H\u00e9r kemur \u00ed lj\u00f3s a\u00f0 n\u00e1kv\u00e6m rann\u00f3kn \u00e1 hra\u00f0afr\u00e6\u00f0i hvarfsins, \u00fear sem notast er vi\u00f0 rafefnafr\u00e6\u00f0ilegt rafskauts-v\u00f6kva samskeytal\u00edkan, sp\u00e1ir fyrir um svipa\u00f0an hvarfgang og \u00e1\u00f0ur hefur veri\u00f0 gert me\u00f0 einf\u00f6ldu varmafr\u00e6\u00f0ilegu l\u00edkani.<\/p>\n

Um doktorsefni\u00f0<\/strong>
Ebrahim Tayyebi h\u00f3f bakkal\u00e1rn\u00e1m sitt \u00ed efnaverkfr\u00e6\u00f0i \u00e1ri\u00f0 2005 vi\u00f0 Arak h\u00e1sk\u00f3lann \u00ed Arak, \u00cdran og lauk \u00fev\u00ed \u00e1ri\u00f0 2009. \u00dear vann hann me\u00f0al annars me\u00f0 pr\u00f3fessor Mostafa Keshavarz Moraveji vi\u00f0 a\u00f0 rannsaka \u00e1hrif hitastigs, \u00fer\u00fdstings og mismunandi hj\u00e1lparefna til a\u00f0 mynda loftkennd h\u00fddr\u00ed\u00f0 \u00ed vatni.
A\u00f0 loknu BS-pr\u00f3fi h\u00f3f hann meistaran\u00e1m \u00ed efnaverkfr\u00e6\u00f0i vi\u00f0 Amirkabir t\u00e6knih\u00e1sk\u00f3lann \u00ed Teran, \u00cdran \u00fear sem hann vann me\u00f0 pr\u00f3fessor Hamid Modarress vi\u00f0 a\u00f0 rannsaka e\u00f0lisefna-eiginleika samskeyta milli fasts efnis og v\u00f6kva \u00e1 nan\u00f3skala. Ebrahim brautskr\u00e1\u00f0ist me\u00f0 meistarapr\u00f3f \u00e1ri\u00f0 2012. <\/p>\n

Ebrahim h\u00f3f doktorsn\u00e1m vi\u00f0 H\u00e1sk\u00f3la \u00cdslands \u00e1ri\u00f0 2016. \u00cd doktorsritger\u00f0 sinni notar hann skammtafr\u00e6\u00f0ilega t\u00f6lvureikninga til a\u00f0 rannsaka hvarfgang rafefnafr\u00e6\u00f0ilegrar afoxunar \u00e1 N2 og CO2 sameindunum fyrir \u00e1bur\u00f0ar og eldsneytisframlei\u00f0slu.<\/p>\n<\/div><\/div>","protected":false},"featured_media":1889,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"_phd_date_start":"2020-10-22T14:00:00+00:00","_phd_date_end":"2020-10-22T16:00:00+00:00","_phd_location":"A\u00f0albygging H\u00e1t\u00ed\u00f0arsalur","_phd_admission":"A\u00f0gangur \u00f3keypis","_phd_thesis_title":"Rafefnafr\u00e6\u00f0ileg CO2 og N2 afoxun \u00e1 m\u00e1lmum og m\u00e1lmox\u00ed\u00f0um (Modeling electrochemical CO2 and N2 reduction reactions on transition metals and metal oxides)","_phd_source_url":"https:\/\/gamli.hi.is\/vidburdir\/doktorsvorn_i_efnaverkfraedi_ebrahim_tayyebi","_phd_source_node_id":"368181","_phd_source_type":"vidburdir","_phd_member_id":513,"footnotes":""},"phd_school":[108,93],"phd_discipline":[109],"class_list":["post-6102","phd_defence","type-phd_defence","status-publish","has-post-thumbnail","hentry","phd_school-idnadarverkfraedi-velaverkfraedi-og-tolvunarfraedideild","phd_school-verkfraedi-og-natturuvisindasvid","phd_discipline-phd-i-efnaverkfraedi"],"_links":{"self":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6102","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence"}],"about":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/types\/phd_defence"}],"version-history":[{"count":0,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6102\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media\/1889"}],"wp:attachment":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media?parent=6102"}],"wp:term":[{"taxonomy":"phd_school","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_school?post=6102"},{"taxonomy":"phd_discipline","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_discipline?post=6102"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}