Kataliye aad waxtar u leh oo u beddela gaasta propane-ga oo u beddela karbohaydraytyo culus ayaa waxaa soo saartay Jaamacadda Sayniska iyo Tignoolajiyada ee Boqor Cabdallah ee Sucuudiga. (KAUST) cilmi-baarayaal. Waxay si weyn u dedejisaa falcelinta kiimikaad ee loo yaqaan metathesis alkane, taas oo loo isticmaali karo in lagu soo saaro shidaal dareere ah.

Kiciyahu waxa uu dib u habeeyaa propane, kaas oo ka kooban saddex atamka kaarboon, molecules kale, sida butane (ka kooban afar kaarboon), pentane (oo leh shan kaarboon) iyo ethane (laba kaarboon ah). "Ujeedkayagu waa inaan u beddelno alkanes-ka miisaanka kelli ee hoose una beddelno alkanes-naaftada qiimaha leh," ayuu yiri Manoja Samantaray oo ka socda Xarunta Kastiiminta ee KAUST.

Wadnaha kicinta waxa ku jira iskudhisyo ka kooban laba bir, titanium iyo tungsten, kuwaas oo ku xidhan dusha silica iyada oo loo sii marayo atamka oksijiinta. Istaraatiijiyadda la isticmaalay waxay ahayd catalysis by design. Daraasadihii hore waxay muujiyeen in kicinta monometallic ay ku hawlanaayeen laba hawlood: alkane ilaa olefin ka dibna olefin metathesis. Titanium waxaa loo doortay sababtoo ah awoodda ay u leedahay in ay dhaqaajiso curaarta CH ee paraffins si ay u beddesho olefins, iyo tungsten waxaa loo doortay waxqabadkeeda sare ee olefin metathesis.

Si loo abuuro kicinta, kooxdu waxay kululaysay silica si ay meesha uga saarto biyaha ugu badan ee suurtogalka ah ka dibna waxay ku dareen hexamethyl tungsten iyo tetraneopentyl titanium, samaynta budo iftiin-huruud ah. Cilmi-baadhayaashu waxay daraasad ku sameeyeen kicinta iyaga oo isticmaalaya spectroscopy resonance nukliyeerka (NMR) si ay u muujiyaan in tungsten iyo atamyada titanium ay si aad ah isugu dhow yihiin sagxadaha silica, laga yaabee inay u dhow yihiin ≈0.5 nanometers.

Cilmi-baadhayaashu, oo uu hogaaminayey agaasimaha xarunta Jean-Marie Basset, ayaa markaa tijaabiyay kicinta iyaga oo ku kululeynaya 150 ° C propane muddo saddex maalmood ah. Ka dib markii la hagaajiyay xaaladaha falcelinta - tusaale ahaan, iyada oo u oggolaanaysa propane inuu si joogto ah ugu socdo kicinta - waxay ogaadeen in alaabta ugu muhiimsan ee falcelinta ay yihiin ethane iyo butane iyo in mid kasta oo ka mid ah tungsten iyo atomyada titanium ay kicin karaan celcelis ahaan 10,000 wareegyo ka hor. luminaya dhaqdhaqaaqooda. "Lambarka wareegtada" waa kii ugu sarreeyay ee abid laga soo sheego falcelinta metathesis propane.

Guushaan katalose ee naqshadeynta, cilmi-baarayaashu waxay soo jeedinayaan, waxaa sabab u ah saameynta iskaashiga la filayo ee ka dhexeeya labada birta. Marka hore, atamka titanium wuxuu ka saaraa atamka hydrogen ka propane si uu u sameeyo propene ka dibna tungsten atamka deriska ah wuxuu jebiyaa propene ee kaarboon-carbon double bond, abuurista jajabyo isku dari kara hydrocarbons kale. Cilmi-baadhayaashu waxay sidoo kale ogaadeen in budada kicinta ay ku jiraan kaliya tungsten ama titanium ay si aad u liidato; xataa marka labadan budo jidh ahaan la isku daray, wax qabadkoodu ma ahayn mid u dhigma kicinta iskaashiga.

Kooxdu waxa ay rajaynaysaa in ay naqshadeeyaan kataliye ka sii fiican oo leh tiro wareeg ah, iyo cimri dheer. "Waxaan aaminsanahay in mustaqbalka dhow, warshaduhu ay qaadan karaan habkayaga si loo soo saaro alkanes-ka naaftada ah iyo in ka badan guud ahaan naqshadeynta," ayuu yiri Samantaray.